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VERITAS Storage Foundation5.0 for UNIX: Maintenance

100-002353-8

COURSE DEVELOPERS

(;ail Adey

Bill4t.'Gerrits

TECHNICALCONTRIBUTORS ANDREVIEWERS

Jade Arrtngton

Marg) Cassid)l{fI) FreemanJue (;allagherBruce(;arncrTomer (~urantzBill Havey(;l'm,' Henriksen(;l'rald JacksonRavmond KarnsHill LehmanIIflh LucusDartvoue 'IanikhongChrlstian Rabanusnaw I{flgers

Kleber SaldanhaAlbrecht Seriha,\lieh.1 Simoni

Ananda Sil'iscnuPete TtH..-m mes

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No part uf the COIlIL'lIts of this honk Illay be reproduced or transmitted inany lonu or by ilny means without the written permission of the publisher.

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Table of Contents

Course IntroductionVERITAS Volume Manager Maintenance TasksVERITAS Storage Foundation Curriculum .

Lesson 1: Maintaining Data ConsistencyResynchronization Operations .Interpreting State Information for VxVM ObjectsModifying VxVM Object States ..

Lesson 2: Managing Devices Within the VxVM ArchitectureManaging Components in the VxVM Architecture.Discovering Disk Devices... . .Managing Multiple Paths to Disk Devices .

Lesson 3: Encapsulation and RootabilityPlacing the Boot Disk Under VxVM ControlCreating an Alternate Boot Disk ..Removing the Boot Disk from VxVM Control.

Lesson 4: Troubleshooting the Boot ProcessOperating System Boot Processes .Troubleshooting the Boot Process .Recovering the Boot Disk Group ..

Lesson 5: Volume MaintenanceChanging the Volume Layout..... .Managing Volume Tasks... .Analyzing Volume Configurations with Storage Expert .

Lesson 6: Performance MonitoringStorage Performance Analysis Process ..VxVM Performance Monitoring Tools and Techniques

Lesson 7: Point-ln-Tlme CopiesWhat Is a Point-In-Time Copy? ...Types of PITC Solutions in Storage Foundation ..Creating and Managing Volume Snapshots .Using Volume Snapshots for Off-Host ProcessingCreating and Managing Storage Checkpoints .

Lesson 8: Other Enterprise Features OverviewWhat Is Dynamic Storage Tiering? .What Is Intelligent Storage Provisioning? .What Is the Storage Foundation Management Server? .

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Table of Contents

Appendix A: Lab ExercisesLab 1: Maintaining Data Consistency ...Lab 2: Managing Devices Within the VxVM ArchitectureLab 3: Encapsulation and Rootability... .Lab 4: Troubleshooting the Boot Process ..Lab 5 Volume Maintenance. .Lab 6: Performance MonitoringLab 7 Point-in-Time Copies.

Appendix B: Lab SolutionsLab 1 Solutions: Maintaining Data Consistency ..Lab 2 Solutions: Managing Devices Within the VxVM Architecture.Lab 3 Solutions: Encapsulation and Rootability ....Lab 4 Solutions: Troubleshooting the Boot ProcessLab 5 Solutions: Volume Maintenance ...Lab 6 Solutions: Performance Monitoring .Lab 7 Solutions Point-in- Time Copies ..

Appendix C: Boot Processes and VxVM Start-Up ScriptsVxVM and the Solaris Boot Process.VxVM and the HP-UX Boot Process

Index

. A-3· A-13

.... A-25· A-35

. A-43.... A-49

· A-63

. B-3... B-21

. B-37.. B-51

. B-65

. B-75.. B-97

..... C-2....... C-15

VERITAS Storage Founttetion 5.0 for UNIX: Maintenance

Course Introduction

How does VxVM integrate into my systemarchitecture?

· How do I discover new devices?

· How do I manage dynamic multlpathing?

How can I recover critical data?

· How do I resolve disk failure?

· How do I recover a plex?· How do I recover the boot disk?

How can I accelerate access to critical data?

· Where are the performance problems?

· How is my hardware affecting performance?

· How do I tune VxVM and optimize I/O?

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VxVM Maintenance

DeviceManagement

RecoveryManagement

PerformanceManagement

VERITAS Volume Manager Maintenance TasksBefore you perform any maintenance tasks, you should understand the VxVMarchitecture and how to manage devices connected to your system.

When you encounter a problem on a system running VERITAS Volume Manager,you must know how to accurately identify the problem and select the appropriatesolution. By learning how to use Vx VM recovery tools and apply recoverytechniques in appropriate ways, you can troubleshoot problems that may occur inyour environment and minimize the loss of critical data.

A variety or factors. such as hardware. location or data on drives. and theapplication I!O profile. can impact the performance of VlRITAS VolumeManager (VxVM). The pcrtonnancc management techniques discussed in thistraining enable you to idcmily and remove performance bottlenecks withoutdisrupting users. and to accelerate accessto critical infornuuion.

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VERITAS Storage Foundation 5.0 for UNIX' Maintenance

Storage Foundation Curriculum Path

VERITAS StorageFoundation for

UNIX:Fundamentals

••••••VERITAS Storage

Foundation forUNIX:

Maintenance

~------------ ------------~-----v--VERITAS Storage Foundation for UNIX

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VERITAS Storage Foundation CurriculumVERITAS Storag« Foundationfor UNIX: Maintenance training is designed toprovide you with comprehensive instruction on making the most of VERIT ASStorage Foundation.

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Inlro-3Course Introduction

• Lesson 1: Maintaining Data Consistency• Lesson 2: Managing Devices Within the

VxVM Architecture• Lesson 3: Encapsulation and Rootability• Lesson 4: Troubleshooting the Boot

Process• Lesson 5: Volume Maintenance• Lesson 6: Performance Monitoring• Lesson 7: Point-in-Time Copies• Lesson 8: Other Enterprise Features

Overview

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VERITAS Storage Foundation for UNIX: Maintenance Overview

This training provides instruction on device management, troubleshooting,recovery, and performance monitoring lorusers ofVERITAS Storage Foundation.

Objectives

After completing this course. you will be able tu:

Interpret plcx. volume, and kernel states, fix plcx and volume failures by usingVxVM tools. and resolve data consistency problems by analyzing plex states.

Describe the Vx VM architecture and manage the device discovery layer anddynamic multipathing feature.Place the rout disk under Vx Vlvl control and mirror the root disk.

Identify boot processes. debug VxVM during system start-up, and resolve bootdisk problems.

Rccoufigurc volumes online and use the Storage Expert utility to analyzevolume configurations,

Monitor VxVM performance and identify how volume configuratiouscontribute tu performance optimization.

Create and manage Instant volume snapshots and storage checkpoints,

Describe Dynamic Storage Tiering (DST). Intelligent Storage Provisioning(ISP). and the Storage Foundation Management Server (SFMS).

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VERITAS Storage Fountietiot) 5.0 for UNIX: Meintenence

Course Resources

• Lab Exercises (Appendix A)• Lab Solutions (Appendix B)• Boot Processes and VxVM Start-Up Scripts

(Appendix C)

Additional Course Resources

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Appendix A: Lab Exercises

This section contains hands-on exercises that enable you to practice the conceptsand procedures presented in the lessons.

Appendix B: Lab Solutions

This section contains detailed solutions to the lab exercises for each lesson.

Appendix C: Boot Processes and VxVM Start-Up Scripts

This section contains a summary of the scripts involved in VxVM startup.

Course Introduction

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Intro-5

Typographic Conventions Used in This Course

The following tables describe the typographic conventions used in this course.

Typographic Conventions in Text and Commands

Cuuveution

Courier New.bold

Element

Command input.both syntax andexamples

Examples

To display the robot and drive configuration:tpconfig -d1"0 display disk information:vxdisk -0 alldgs list

Courier New.plain

Courier New,Italic. bold orplain

Command outputCommandnames. directorynames. tilenames. pathname'S. usernames.passwords. L RLswhen used within1"1'glll'll'tcxt

paragraphs,

Varia hies incommand syntax.and examples:

Variables incommand inputarc Italic. plain.Variable, incommand (Hit putarc Italic. bold.

In the output:protocol minimum: 40protocol_maximum: 60protocol current: 0Locate the al tnames directory.Cio to http://www.symantec.com.l.nrer the value 300.Log 011 asuser 1.

To install the media server:/ cdrom_ directory/ installTo ~I\•.cessa manual page:man command nameTo display detailed information tor a disk:vxdisk -g disk_group listdisk name

Convention

Typographic Conventions in Graphicailiser Interface Descrlptlons

Arrow

Element Examples~--------------~

Menu navigarion paths Select l-ile- ->Save,

Initial capitalization Hunons. menus. window». Select tire Next button.options. and other interface Open the Task Statusclements window.

Remove the checkmarkfrom the Print File checkbox.

Quotation marks Interface clements withlong names

Select the "Includesubvolumes in object viewwindow' check box.

lntro-B VERITAS Storage Foundation 5.0 for UNIX: Maintenance

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Lesson 1

Maintaining Data Consistency

Lesson Introduction• Lesson 1; Maintaining Data •••.. _Q~n~s~st~'!.£l'______.~ --i

• Lesson 2: Managing Devices Withinthe VxVM Architecture

• Lesson 3: Encapsulation andRootability

• Lesson 4: Troubleshooting the BootProcess

• Lesson 5: Volume Maintenance• Lesson 6: Performance Monitoring• Lesson 7: Point-in-Time Copies• Lesson 8: Other Enterprise Features

Overview

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Lesson Topics and Objectives

Topic After completing this lesson, youwill be able to:

--Topic 1: Resynchronization Describe mirror resynchronizationOperations processes.Topic 2: Interpreting State Interpret plex state and conditionInformation for VxVM flags, volume states, and kernelObjects states.Topic 3: Modifying VxVM Fix plex and volume failures by usingObject States VxVM tools.

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IResynchronization is the process of ensuring that after asystem crash:• All mirrors in a volume contain exactly the same data.

• Data and parity in RAID-5 volumes agree.

Ig~~~:::==~1Did all writes'; complete?

Do all mirrorscontain thesame data?

Types of mirror resynchronization:• Atomic-copy resynchronization• Read-writeback resynchronization

Resynchronization Operations

What Is Resynchronization?

Resynchronization is the process of ensuring that. after a system crash:

All mirrors in mirrored volumes contain exactly the same data.

Data and parity in RAID-5 volumes agree.

Data is written to the mirrors of a volume in parallel. If a system crash occursbefore all the individual writes complete. some writes may complete while otherwrites do not. This system crash can cause 111'0 reads from the same region of thevolume to return different results ifdifferent mirrors are used to satisfy the readrequest. In the case of RA ID-5 volumes. two reads returning different results canlead to rarity corruption and incorrect data rcconstrucuon. VxVM uses volumeresynchronization processes to ensure that all copies of the data match exactly.

VxVM records when a volume is first written to and marks it as dirty. When avolume is closed by all processes or stopped cleanly by the administrator. allwrites have been completed. and Volume Manager removes the dirty flag for thevolume. Only volumes that are marked dirty when the system reboots requireresynchronization.

Not all volumes require resynchronizarion after a system failure. Volumes thatwere never written or that had no active 1/0 when the system failure occurred donot require resynchronization.

The volume is completely accessible during the two modes of resynchronizaiion.

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Atomic-Copy Resynchronization

Atomic-copy rcsynchronizauon refers to the sequential writing of ~II blocks of thevolume to a plcx. This operation is used anytime a new mirror is added to avolume, or all existing mirror is in stale mode and has to be rcsynchronizcd.

Atomic-Copy Resynchronization

Atomic-copy resynchronization involves thesequential writing of all blocks of a volume to a plex.

This type of resynchronization is used in:• Adding a new plex (mirror)• Reattaching a detached plex (mirror) to a volume• Online reconfiguration operations:

- Moving a plex- Copying a plex- Creating a snapshot- Moving a subdisk

Atomic-Copy Resvnchrunizatlon Process1 The plcx being copied to is set tu a write-only state.2 A read thread is started on the whole volume. (Every block is read intcrnally.)

3 Blocks arc written from the "good' plcx tu the stale or new plcx.

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Read-Writeback Resynchronization

Read-writeback resynchronization makes all plexesidentical by alternately copying regions betweenplexes.

This type of resynchronization is used in:• Recovery of mirrors after a system crash• Growing a volume

In this type of resynchronization:• Mirrors marked ACTIVE remain ACTIVE, and the

volume is placed in the SYNC state.

• An internal read thread is started. Blocks are readfrom the plex specified in the read policy, and thedata is written to the other plexes.

• Upon completion, the SYNC flag is turned off.

Read-Writeback Resynchronization

Read-writeback rcsynchronization is a process of ensuring that two plcxes havethe same content.

Because the application must ensure that all writes arc completed. the applicationmust fix any writes that are not completed. The responsibility ofYxYM is toguarantee that the mirrors have the same data.

A database (as an application) usually docs this by writing the original databack to the disk.A tile system checks to ensure that all of its structures are intact. Theapplications using the tile system must do their own checking.

Read-Writeback Resynchronlzatlon ProcessAll plexes that were ACTIVE at the time of the crash are set to the ACTIVEstate again. and the volume is placed in the SYNC state (or the NEEDSYNC stateif the disk group has more than one volume).

2 An internal read thread is started to read the entire volume. and blocks are readfrom whatever plex is in the read policy and are written hack to the otherplexcs, Because the default read policy is Select and this chooses Round Robinover Preferred. blocks are read from one plcx and written to another.alternately.

3 When the resynchronization process is complete. the SYNC flag is turned off(set to ACTIVE).

User-initiated reads are also written to the other plexcs in the volume but otherwisehave 110 effect 011 the internal read thread.

Lesson 1 Maintaining Data Consistency

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1-5

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Impact of Resynchronization

Resynchronization takes time and impactsperformance.To minimize this performance impact, VxVM providesthe following solutions:

• Dirty region logging for mirrored volumes

• RAID-5 logging for RAID-5 volumes

• FastResync for mirrored and snapshot volumes

Minimizing the Impact of Resynchronization

The process of rcsynchronizauon call impact system performance and can taketime. Tu minimize the performance impact otrcsynchronizmion. VxVM provides:

Dirty region lugging lor mirrored volumesRAID-5 logging lor RAID-5 volumesFastResync lor mirrored and snapshut volumesTill; FastResync option requires the lluslrSnup license.

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Dirty Region Logging• For mirrored volumes with logging enabled, DRL

speeds plex resynchronization. Only regions thatare dirty need to be resynchronized after a crash.

• If you resize a volume, the log size does not change.To resize the log, you must delete the log and add itback after resizing the volume.

Dirty Region Logging

You were introduced to dirty region logging (DRL) when you created a volumewith a log. This section describes how dirty region logging works.

How Does DRL Work?

DRL logically divides a volume into a set of consecutive regions and keeps trackof the regions to which writes occur. A log is maintained that contains a status bitrepresenting each region of the volume. For any write operation to the volume. theregions being written are marked dirty in the log before the data is written.

If a write causesa log region to become dirty when it was previously clean. the logis synchronously written to disk before the write operation can occur. On systemrestart, VxVM recovers only those regions of the volume that are marked as dirtyin the dirty region log.

Log subdisks store the dirty region log of a volume that has DRL enabled.Only one log subdisk can exist per plex.Multiple log subdisks can be used to mirror the dirty region log.I f a plcx contains a log subdisk and no data subdisks. it is called a log pier.

Only a limited number of bits can be marked dirty in the log at any time. The dirtybit for a region is not cleared immediately after writing the data to the region.Instead. it remains marked as dirty until the corresponding volume region becomesthe least recently used.

1-7Lesson 1 Maintaining Data Consistency

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ji·}_I·Dirty Region Logging: Example

0123 ...[0010000.-::-0 0 1 0 0 .. 0 0 0 ... 0 0~iiJ01 23 ...

[O!OOOOO ... 00000 .. 000 ... O~

ActiveBitmap

VolumeDRL Before a Crash

J=;;:;::::I 0123

RecoveryBitrnap

IIDRL After a Crash

~ 0123 ...

): : LL_~_~_:_1_~_:_':_:_,,_. _:_:_:_0_0_:_·._:·._:_:_:_·.·.·_.:_O_~_:_:_:_:_I_R_~_~~_~_~_;y---J

Dirty Region Log Size

In the dirty region log:A small number of bytes of the DRL arc reserved for internal use. Theremaining bytes arc used forthe DRL biunap,

The bytes arc divided into two bitmaps: an active biunap and a recoverybiunap.Each bit in the active biunap maps to a single region of the volume.

A maximum of 204S dirty regions per system is allowed by default.

How the Bitmaps Are Used in Dirty Region Logging

Both bitmaps arc zeroed when the volume is started initially, after a cleanshutdown. As regions transition to dirty, the corresponding bits arc set before thewntcs to the volume occur.

I f the system crashes, the activ c map is OR' d with the recovery map.Mirror rcsyuchronizatiun is now limited to the dirty bits in the recovery map.The active map is simultaneously reset, and normal volume \''0 is permitted.

Usage of two biunaps in this way allows VxVM to handle multiple system crashes.


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Why Is It Important to Understand Object States• VxVM uses plex and volume states or condition flags to decide:

- If a volume can be started- If a mirrored volume needs any synchronization- Which copy of data (plex) is to be used as the source if

synchronization is required- If I/O is allowed to different copies of data (plexes)

• You may need to manipulate plex or volume states under certainconditions:- To recover volumes if one or more failures prevent VxVM from

taking automatic recovery actions- To recover from situations where interrupted configuration

tasks leave volumes in unusable states- To take specific copies of data out of the I/O path for

maintenance purposes- Use disk group configuration backups to create specific

configurations

Interpreting State Information for VxVM ObjectsVxVM uses plcx and volume states or condition Ilags to decide which operationscan be performed.

You may need to manipulate plex or volume states under certain conditions.


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How Volumes Are Created

vxassist is a top-down utility-that is, you onlyspecify the properties of the volume you want tocreate-that creates volumes bottom-up:

1. Create subdisks.

2. Associate subdisks to plexes.

3. Associate plexes to a volume.

4. Initialize the volume's plexes.

5. Start the volume.

How Volumes Are Created

In order to troubleshoot and solve problems associated with mirrors, you mustunderstand how volumes arc created. The vxassi st utility is a top-down utility.which means that you specify only the properties of the volume that you want tocreate. However, vxassist actually creates the volumes using a bottom-upapproach. which means that subdisks an: created first and used to build volumes.

To create a volume, vxassi st follows this process:

Determine where you \1 ill place the data and create subdisks on the appropriatedisk drives.

2 Create mirrors and associate each of the subdisks to the mirrors that will beused in the volume.

3 Create the volume and associate the mirrors to the volume. The result is avolume with one or more plcxcs.

4 Initialize the volume's plcxcs by selecting the plcx that represents the data forthe volume. You perform this action by using the vxvol ini t command.

Initializing a volume is similar to using a low-lcvcl lormat command on a diskdrive: it states how to nuvig.uc to the data. (13y default. vxassist createsboth plcxcs as hay ing the data and copies them together-using rcad-writcbacksynchronization. )

5 Start the volume. Starting a volume involves enabling the area that the volumerepresents on disk, and enabling its object in the disk group configurationdatabase. to accept user and system 1,'0.

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Identifying Plex Problems

To identify and solve pie x problems, use thefollowing information:• Plex states• Volume states• Plex kernel states• Volume kernel states• Object condition flags

Commands to display plex, volume, and kernel states:vxprint -g diskgroup -ht [volume_name]

vxinfo -p -g diskgroup [volume]

You can use STATE fields in the output of the vxprint and vxinfo commandsto determine that a problem has occurred, and to assist in determining how to fixthe problem, VxVM displays state information for:

Plcx statesVolume statesPlcx kernel statesVolume kernel states

Identifying Plex Problems

The plex and volume state fields are not always accurate, because administratorscan change them. However. kernel state flags are absolute; that is, only VxVM canchange them. Therefore, kernel state flags arc always accurate.

A particular plex state docs not necessarily mean that the data is good or bad. Theplex state represents VxVM's perception of the data in a plex. VxVM is usuallyconservative; that is, ifVxVM detects that data is not synchronized. then the plcxstates are set accordingly.

Lesson 1 MaintainingData ConsistencyCOOY(1g111 'f) 2006 Symantec Corporation All nqt-ts reserved

1-11

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Displaying Object States

vo I volOlplex voIDl-Q!

plex volOl-02

Esgen

ACTInACTIVE

Sta.rtedvxinfo -p -g datadg volOl

vxprint -g datadg -ht volOlv NAME PVG!VSET/CO KSTATE STATE LENGTH READPOL PREFPLEX

UTYPE

PL NAME VOLUME KSTATE STATE LENGTH LAYOUT NeQL/WID MODE

so NAME PLEX DISK DISKOFFS LENGTH [COLI) OFF DEVICE MODEsv NAME PLEX VOLNAME NVOLLA YR LENGTH tcor./: aFF !>.MINH MODE

v voiOl ENABLED ACTIW 204800 SELECT fsgenpi \10101-01 volO! ENABLED ACTIV!: 205200 CONCAT RWad datadgOl 01 voIOl-O! datadgOl 0 205200 0 diskO 1 ENAp I volOl-02 voiOl ENABLED ACTIVE 205200 CONCAT RWsd datadg02-01 volOl-02 datadg02 0 205200 0 diskO 2 ENA

Example of vxinfo and vxprint

If you do not specify the volume name on the command line for the vxprint orvxinfo commands, information on all the volume, within the specified diskgroup is displayed.


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Plex States and Condition FlagsEMPTY

• CLEAN (SNAPDONE)

ACTIVE (SNAPDONE) Pl:ENABLED/ACTIVEP2:ENABLED/ACTIVE[V: ENABLED/ACTIVE]

I vxvol start ~J Eval stopviKey

~

Pl:DISABLED/CLEANP2:DISABLED/CLEAN[V: DISABLED/CLEAN]

iP1: 1st Plex States jP2: 2nd Plex States 1[v: Volume States} i

Interpreting Plex States

Plex StatesEMPTY: When you creme a volume, all of the plexes and the volume are set to theEMPTY state. This state indicates that you have not yet defined which plex has thegood data (CLEAN). and which plcx does not have the good data (STALE). You canonly achieve the EMPTY state by creating a new volume using vxmake. or byusing related administrative commands.

CLEAN: The CLEAN state is normal and indicates that the plex has a copy of thedata that represents the volume. CLEAN also means that the volume is not startedand is not currently able to handle 110 (by the administrator's control).

ACTIVE: The ACTIVE state is the same as CLEAN. but the volume is or wascurrently started, and the volume is or was able to perform 110.

SNAPDONE: The SNAPDONE state is the same as ACTIVE or CLEAN, butSNAPDONE is a plcx that has been synchronized with the volume as a result of avxassist snapstart operation. After a reboot or a manual start of thevolume. a plcx in the SNAPDONE state still exists. It is persistent.

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Plex States and Condition FlagsSTALE (SNAPATT)OFFLINE

TEMP

Key

~P1: tst Plex StatesP2: 2nd Plex States[V: Volume States)

STALE: The STALE state indicates that VxVM detects that the data in the plcx isnot synchronized with the data in the CLEAN plcxcs. This state is usually causedbytaking the plcx offline (110 can still be going to the other plcxcs, making themunvynchronizcd) or by a disk tailurc-c-which means that the plcx was not updatedwhen new writes came into the volume.

SNAPATT: The SNAPATT state indicates that the object is a snapshot that iscurrently being synchronized but docs not yet have a complete copy of tile data.

OFFLINE: The OFFLINE stare indicates that the administrator has issued thevxmend of f command on the plcx. The plcx does not participate in any I/O whenit is offline, so actively writing to the volume causes the contents to becomeoutdated. When the administrator brings the plcx back online using the vxmendon command, the plcx changes to the STALE state.

TEMP: The TEMP state flags (TEMP, TEMPRM, TEMPRMSD) usually indicate that thedata was never a copy olthc volume's data, and it is recommended that you not usethese plcxcs. These temporary states indicate that the plcx is currently involved ina synchronization operation with the volume,

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Note: If the volume is nonredundant at the time thatyou reattach the drive, the plex state changes fromNODEVICE to FE COVER instead of IOFAIL.

Condition Flags

If a plcx is not synchronized with the volume and VxVM has information aboutwhy it is not synchronized. then a condition flag is displayed. Multiple conditionflags can be set on the same plex at the same time. Only the most informative flagsare displayed in the state field of the vxprint output. For example, if a disk failsduring an I/O operation, the NODEVICE, IOFAIL, and RECOVER flags arc all setfor the plex, but only the NODEVICE flag is displayed in the state field.

NODEVICE: NODEVICE indicates that the disk drive below the plcx has failed.

REMOVED: REMOVED has the same meaning as NODEVICE. but the systemadministrator has requested that the device appear to have failed (for example. byusing the vxdiskadm option. "Remove a disk for replacement").

IOFAIL: IOFAIL is similar to NODEVICE, but it indicates that an unrecoverablefailure occurred on the device, and VxVM has not yet verified whether the disk isactually bad. (110 to both the public and the private regions must fail to change thestate from IOFAIL to NODEVICE.)

RECOVER: The RECOVER flag is set on a plcx when two conditions arc met:

A failed disk has been fixed (by using vxreattach or the vxdiskadmoption, "Replace a failed or removed disk").

The plex was in the ACTIVE state prior to the failure,

This flag indicates that even after fixing the volume, additional action tlIay berequired. The data may be lost and must be recovered from backup, or theadministrator must verify that the data on the disk is current by using utilitiesprovided by the application that uses that volume.

Lesson 1 Maintaining Data Consistency 1-15

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Volume States

• EMPTY } These volume states have the same• CLEAN meanings as they do for plexes.

ACTIVE

• NEED SYNC This state is the same as SYNC, butthe internal read thread has notbeen started.

• SYNC Plexes are involved in read-writeback or RAIO-5 paritysynchronization.

• NODEVICE None of the plexes have currentlyaccessible disk devicesunderneath the volume.

Interpreting Volume States

Volume States

EMPTY, CLEAN. and ACTIVE: The EMPTY. CLEAN. and ACTIVE volume stateshave the same meanings as they do for plcxcs.

NEEDSYNC: The NEEDSYNC volume state is the same as SYNC, but the internalread thread has not been started. This state exists so that volumes that use the samedisk arc not synchronized at the same time, and head thrashing is avoided.

SYNC: The SYNC volume state indicates that the plcxcs arc involved in read-writcback or RAID-S parity synchronization:

Each time that a read occurs from a plcx, it is written back to all the otherplcxcs that arc in the ACTIVE state.

An internal read thread is started to read the entire volume (or, alter a systemcrash. only the dirty regions ifdirty region logging (DIU.) is being used).forcing the data to be synchronized completely. On a RAID-S volume, thepresence ofa RAID-S log decreases the time ofa SYNC operation.

Starting an empty mirrored volume by using the vxvol start command placesthe volume in SYNC mode.

NODEVICE: The NODEVICE volume state indicates that none of the plcxcs havecurrently accessible disk devices underneath the volume.


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Kernel StatesKernel states represent VxVM's ability to transfer 110to the volume or plex.

• ENABLED The object can transfer both system110and user 110.

The object can transfer system 110,but not user 110(maintenance mode).

No 110can be transferred.

Kernel states represent VxVM\ ability to transfer 1/0 to the object.Volume kernel stat 1': VxVM's ability to transfer I/O to the volumePlex kernel state: VxVM's ability to transfer I/O to the plex

ENABLED: The ENABLED kernel state indicates that the object is currently able totransfer system I/O to the private region and user I/O to the public region.

DETACHED: The DETACHEDkernel state indicates that the object can currentlytransfer system I/O. but 110t user [/0. This state is also considered the maintenancemode where internal plex operations and ioct 1 functions arc accepted.

DISABLED: The DISABLED state is the offline state for the volume or the plex.When all object is in this state. no I/O is transferred.

• DETACHED

• DISABLED

Interpreting Kernel States

Kernel States


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1-17

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Example Scenarios• SCENARIO 1:

- You are planning to go through an upgrade procedure that maycorrupt data. You want to keep one safe copy in case things gowrong.

- You do not have enough space to add snapshot volumes, soyou take one plex out of the 110 path during the upgrade .

• SCENARIO 2:- You are mirroring a critical application data across disk arrays

in multiple sites.- A disaster first causes your remote site to be temporarily

disconnected and then causes the primary copy to be lostpermanently before you can recover from the temporaryfailure.

- You now have the option of using the remote site data, whichis several minutes old, or recovering from last night's backup.

Modifying VxVM Object States

Example Scenarios

Determine the best action 1'01' the: scenarios that arc described on the slide.

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Solving Plex Problems

Commands used to fix plex problems include:

• vxrecover

• vxvol -f start

• vxmend fix

• vxmend off Ion

Resolving Plex Problems

When resolving disk and plcx problems, after you fix the underlying disk drives byusing the disk commands, you must fix plcx problems by using the followingcommands:• vxrecover• vxvol -f start• vxmend fix• vxmend off Ion

Copvnuht (' 2006 Syraantec Corporation. All nqhts reserved


When vxrecover is executed. VxVM notes the state of the plcxcs in the volume.lfboth ACTIVE and STALE plcxcs exist. the ACTIVE plcxcs issue unconditionalblock writes over the STALE plcxcs, If there arc only ACTIVE plcxcs. thercad-wriicback copy procedure is performed.

Recovery is performed only on volumes that require recovery (such as volumesmarked as dirty before a sudden system failure). During the recovery process. thevolume remains online and started. When the synchronization process is complete,the volume and all of its plcxcs arc ACTIVE and ENABLED.

Running vxrecover without specifying a volume name can cause asynchronizauon operation to be started in parallel on all volumes that needrecovery. One synchronization operation runs on each drive (if necessary), andvolumes on different drives are synchronized in parallel.

Synchronization can affect system performance. If you have many volumes thatneed to be recovered. you may prefer to:

Start the volumes without recovery by using vxrecover - sri.

Note: The - s option is only used when the volume is stopped.2 Recover individual volumes or recover all of the volumes when I/O traffic is

lo« by u,ing vxr e cove r.

Note: As lung as one CLEAN or ACTIVE. non-volatile plcx (a plcx with no Ilagsset) is available inside a volume. you can start the volume using that plcx. Theadministrator can recover any other plcxcs in the volume immediately. or deferrecovery to a later time.

Recovering Volumes

vxrecover -g diskgroup -8 [volume]• Recovers and resynchronizes all plexes in a started

volume

• Runs the vxvol start and vxplexattcommands (and sometimes vxvol resync)

• Works in normal situations• Resynchronizes all volumes that need recovery if a

volume name is not included

• Examples:vxrecover -svxrecover -s vol0l

The vxrecover Command

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vxvol -g diskgroup -f start volume name

• This command ignores problems with the volumeand starts the volume.

• Only use this command on nonredundant volumes.If this command is used on redundant volumes,data can be corrupted unless all mirrors have thesame data.

• Example:

vxvol -g datadg -f start volOl

vxvol -f start volume name

When you force a volume to start:

Ifall plexes have the same state. then read-writcback synchronization isperformed.

If the pie xes do not have the same state. then atomic-copy rcsynchronization isperformed.

The vxvol start Command

If a volume does not start with this command. it usually indicates that there is aproblem with the underlying plcxes.

Forcing a Volume to Start

If you add the - f flag. YxYM ignores the underlying problem and forces thevolume to start:

Caution: Force-starting a volume can have catastrophic resuits. Use extremecaution when force-starting a mirrored volume after a disk failure andreplacement. Forcing a mirrored volume to start can unconditionally synchronizethe volume using a rcad-writeback method of alternating between plex blocks.NULL plex blocks may overwrite good data in the volume. corrupting the data.Only perform a forced start 011 a nonredundant volume.


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Modifying Plex and Volume States Manuallysyrnaniec

• The volume that the plex is associated with must be in DISABLEDmode to modify the plex state.

• You may need to move a plex to STALE state as an intermediatestep before changing to CLEAN or ACTIVE state.

• Use this command as a last resort if none of the other recoveryoptions help.

vxmend -g diskgroup fix option object• stale• clean

• active

• empty(only used on a volume)

Examples:vxmend -g datadg fix stale volOl-Olvxmend -g datadg fix clean volOl-Ol

The vxmend Command

To manually reset or change the stare ofa plcx or volume, you can use the vxme ndfix command.

Use this command if you know more about a plcxs data than YxYM docs. Youcan only set plcx states with vxrne nd fix when the host volume or the plcx isstopped.

Caution: Use caution and discretion when issuing the vxmend fix commandand its options. The vxmend fix command changes states set and clearedautomatically by the vxconfigd daemon. Ifused incorrectly. this command canmake the plcx, its volume, and its data inaccessible, and you may have to restorethe data Irom backup.

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VERITAS Storage Foundation 5.0 for UNIX: Maintenance

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vxmend -g diskgrollp on plex_name

Taking Plexes Out of the 1/0 Path

When analyzing plexes, you can temporarily takeplexes offline while validating the data in another plex .

• To take a plex offline, use the command:vxmend -g diskgrollp off plex_name

• To take the plex out of the offline state, use:

vXIIlend off Ion

When analyzing plex problems to determine which plex has the correct data. youmay need to take some plcxes offline temporarily while you are testing a particularplex by using this command.

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Example: If the Good Plex Is Not Known

The volume is disabled and not startable, and you do notknow what happened. There are no CLEAN plexes.

To resolve:

1. Take all but one plex offlineand set that plex to CLEAN.

2. Run vxrecover -so

3. Verify data on the volume.

4. Run vxvol stop.

5. Repeat for each plex untilyou identify the plex withthe good data.

P1 RvolOl-Ol: volOl-02:

DISABLED/STALE :DISABLED/STALE

Analyzing Plex Problems

Example: If the Good l'Icx Is :'IIot Known

What if both plcxcs are in the STALE state? Regardless of what happened to theplcxcs or the disks underneath. it is not sale to guess which plcx has the morerecent (or good) data and start the volume.

I I' you arc not sure which plcx has good data, then the salest solution is to test eachplcx one by one.

1 Take all but one plcx online and set that plcx to CLEAN.

2 Run vxrecover - s.

3 Verify data on the volume. Mount the file system as read-only so you do nothave to run a file system check.

4 Run vxvol stop.

S Repeat for each plcx until you identity the plcx with the good data.

This process requires step-by-step attention 10 all volume and plcx object details.Use vxprint -ht to monitor any volume and plcx state changes that occur as aresult of your vxmend commands.

Without a method to test the validity of the datu, you must restore the data frombackup. For example. if your application is staning. call you guarantee that thedata it contains is the 1110strecent With a Iilc system. is f sck enough to guaranteethat the data in a file is there'! Even if you can mount the file system. you can losethe data in some files in the process.

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If the Good Plex Is Not Known: Example

In the example, you can resolve the problem by using the following commands.

Set the good plex to CLEAN.

vxmend -g diskgroup off volOl-02

vxmend -g diskgroup fix clean volOI-OI

Verity that data is on the plcx by using the volume:

vxrecover -s volDIvxvol -g diskgroupstop volOI

vxmend -g diskgroup -0 force off voIOI-Ol(lastcleanplexinthe volume)

vxmend -g diskgroupon volOl-02

vxmend -g diskgroupfix clean volOl-02

Verity that data is on the plcx by using the volume:vxrecover -s volOI

If the current plex (vol01-02) has the correct data:

vxmend -g diskgroupon volOl-Ol

vxrecover volOI

If vol 01- 01 had the correct data:

vxvol -g diskgroup stop volOl

vxmend -g diskgroup fix stale volOl-02

vxmend -g diskgroup on volOl-Ol

vxmend -g diskgroup fix clean volOI-OIvxrecover -s volDI


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Appendix l3 provides complete lab instructions and solutions. "1 ab 1 S"luiiull''':\lJiIIL}ljJl[l~ !)~!u{ I)li,j'li,.'n<..'l P~!~'..'H··~

Lesson Summary

• Key PointsThis lesson described mirror resynchronizationprocesses. This lesson also introduced the variousstates in which Volume Manager objects. such asvolumes and plexes. can exist and described thetools that you can use to solve problems related todata consistency by analyzing and changing thesestates.

• Reference Materials- VERITAS Volume Manager Administrator's Guide- VERITAS Volume Manager Troubleshooting Guide

Lab 1

Lab 1: Maintaining Data ConsistencyIn this lab, you practice recovering from avariety of plex problem scenarios, andoptionally, observe the benefits of a dirtyregion log during a system crash.To investigate and practice recoverytechniques, you will use a set of interactivelab scripts.

For Lab Exercises, see Appendix A.For Lab Solutions, see Appendix B.

Labs and solutions for this lesson JI'C located on the: Iollo« ing pages:

Appendix A provides complete lab instructions. "1 dh i \Llililciiillnc:: ):i1:1

{·on"i'\kHt.·~,'· pa~i,l'/\"'~


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Lesson 2

Managing Devices Within the VxVMArchitecture

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Lesson IntroductionLesson 1: Maintaining DataConsistency

• ~:~Y;Y~;~~r&;!~~~~ices ~ithin ..-

Lesson 3: Encapsulation andRootabilityLesson 4: Troubleshooting the BootProcessLesson 5: Volume MaintenanceLesson 6: Performance MonitoringLesson 7: Point-in-Time CopiesLesson 8: Other Enterprise FeaturesOverview

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Lesson Topics and ObjectivesTopic After completing this lesson. you will be

able to:Topic 1: ManagingComponents in the VxVMArchitecture

Manage components of the VxVM architecture,including the VxVM configuration database,the configuration daemon, and volboot.

Topic 2: Discovering DiskDevices

Describe the VxVM device discovery function.

Topic 3: Managing MultiplePaths to Disk Devices

• Describe how dynamic multipathing workswith active/active and active/passive diskarrays.

• Prevent multipathing for a specific device.• Disable a specific 110 path.• Control the DMP restore daemon.

2-2 VER/TAS Storage Foundation 5.0 for UN/X: Maintenance

VxVM Architecture

User Applications

File Operating SystemBlock Device Switch [dak]

Character Device Switch (rdsk)

VxVM ConfigDatabases

Managing Components in the VxVM Architecture

VxVM Architecture

VxVM is a device driver that is placed between the UNIX operating system andthe SCSI device drivers. When VxVI'v1 is running. UNIX invokes the VxVMdevice drivers instead of the SCSI device drivers. YxVM determines which SCSIdrives are involved ill the requested I/O and delivers the I/O request to the drives.

VxVM Daemons

YxYM relies on the following constantly running daemons for its operation:vxconfigd- The VxVM configuration daemon maintains disk and groupconfigurations. communicates configuration changes to the kernel. andmodifies contigurution information stored on disks. When a system is booted.the vxdctl enable command is automatically executed to startvxconfigd. YxVM reads the /etc/vx/volboot file to determine diskownership and automatically imports disk groups owned by the host.vxiod The VxYM 1/0 daemon provides extended 1/0 operations withoutblocking calling processes.Several vxiod daemons arc usually started at boottime. and they continue to run at all times.vxrelocd~~vxrelocd is the hot-relocation daemon that monitors eventsthat affect data redundancy. I f redundancy failures are detected. vxrelocdautomatically relocates affected data from mirrored or R!\ID-5 subdisks tospare disks or other free space within the disk group.

~~~~~- --~--~~----Lesson 2 ManagingDevicesWithin the VxVM Architecture 2~3

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VxVM Configuration Database• Contains all disk, volume, plex, and subdisk

configuration records

• Is stored in the private region of a VxVM disk

• Is replicated to maintain a copy on multiple disks ina disk group- VxVM maintains an appropriate number of active

copies per disk group.- Copies are stored across enclosures to maximize

redundancy.

• Is updated by the vxconfigd process

VxVM Configuration Database

The Vx VM configuration database stores all disk. volume. plcx. and subdiskconfiguration records. The vxconf ig device (/ dev/vx/ conf ig) is theinterface through which all changes to the volume driver state are performed. Thisdevice can only be opened by one process at a time. and the initial volumeconfiguration is downloaded into the kernel through this device.

The coufigurution database is stored in the private region ofa VxVM disk. Eachdisk that has a private region holds an entire copy of the configuration database forthe disk group. The size of the configuration database for a disk group is limited bythe size of the smallest copy of the configuration database on any of its memberdisks.

Tile VxVM configuration is replicated within the disk group to protect against lossof the configuration in case of physical disk failure. vxconf igd activelymonitors live or more copies of the configuration database for each disk group.VxYM balances their locations based on the number of controllers. targets anddisks in the disk group.

With VxVM 3.2 and later. VxVM configuration copies are placed across theenclosures spanned by a disk group to ensure maximum redundancy acrossenclosures,

The vxconf igd configuration daemon. is the process that updates theconfiguration through the vxconf ig device. The vxconf igd daemon wasdesigned to be the sole and exclusive owner ofthis device.

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Displaying VxVM Configuration Database Information

ivxdg list acctdgGroup: acctdg _ .. _~gid: . 1023996467.1130. trainsrCOnfi9UrationImpo r t= Ld . 0.1129 database size

config copy 1 len=48144 state=clean onlineconfig disk c1t1dOs2 copy 1 len=48144 state=clean onlineconfig disk c1t2dOs2 copy onlineconfig disk c1t3dOs2 copy 1config disk c1t9dOs2 copyconfig disk c1t10dOs2 copy 1 onlineconfig disk c1t11dOs2 copy 1log disk c1tOdOs2 copy 1 1en=7296log disk c1t1dOs2 copy 1 len=7296

i Not active "I

copies:config:

Displaying Disk Group Configuration Data

To display the status of the configuration database for a disk group:

vxdg list diskgroup

Ifno disk group is specified, information from all disk groups is displayed in anabbreviated format. When you specify a disk group. a longer format is used todisplay the status of the disk group and its configuration.

In the example, live disks have active configuration databases (online). and twodisks do not have an active copy of the data (disabled). The configurationdatabase for a disk group is the size of the smallest private region in the disk group.

Log entries are on all disks that have databases. The log is used by the VxVMkernel to keep the state of the drives accurate if the database cannot be keptaccurate (for example, if the configuration daemon is stopped).

By default. for each disk group, VxVM maintains a minimum of live activedatabase copies on the same controller. In most cases. VxVM also attempts toalternate active copies with inactive copies. In the example. clt3dO and clt9dOare disabled. If different controllers are represented on the disks in the same diskgroup, VxVM maintains a minimum of two active copies per controller.

In the output on the slide, the Configuration database size (pe rml en«) is next toa field named f r e e«. The free= field can be used to check how fast theconfiguration database is filling lip so that action can be taken before the diskgroup runs out of database space.

lesson 2 Managing Devices Within the VxVM Architecture 2-5Copyright '," 2006 Symanter Corporancn. ,\.11nallis reserved

Displaying Disk Header Information

The terms displayed in the output oi'vxdisk list include:

Term Descriptionf----------+-Full LNIX de\ ice name otdiskDevice

Device name used by VxVM to refer to the physical disk

type Method of placing the disk under VxVM control~------------4------------------------------------------------

devicetag

hostid Name of system that manages the disk group (If blank, no host iscurrently controlling this group.)

Disk group name and internal ID

disk VM disk media name and internallD

info

group

flags

Disk fonnat. private region offset, and partition numbers forpublic and private regions

------------------------Settings that describe status and options till' the disk

Paths for block and character device tiles of the public region "I'the disk

pubpaths

iosize The iosize range that the disk accepts

version Version number of header format

public,private

Partition (slice) number. offset trorn beginning of the partition.length of the partition. and disk offset

2--6

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config priv 000256-048207 [047952] :copy=Oloffset=000192 enabledlog priv 048208-055503 [007296] :copy=01offset=OOOOOOenabledlockrgn priv 055504-055647[000144] :part=Ooffset=OOOOOO

configurationdatabase copies,logs, and lock

;-i="7'===~=:;;;;;:7':~:::::7.~;;;;;;;;;:;;;;;;;;;;~~Last update to the private regionand location of header (sector 0)and offset to header copies

~~~~"":~~=-r.~7'Z''1''Trr----1 (sector 240)

Defined regions:config priv 000048-000239 [000192] :copy=01 Location ofoffset=OOOOOOenabled

Multipathing information:numpaths: 2cltOdOs2 state=enabledc2tOdOs2 state=disab

The following is a continuation of vxdi sk 1 i st output descriptions:

Term Description

update Date, time, and sequence number ofthe last update to the private

ssb region

headers Offset to two copies of the private region header

configs Number of configuration database copies kept in the privateregion

logs Number ofkerncllogs kept in the private region

Defined Location ofconfiguration databases, kernel logs, and lock regionsregions in the private region

Because the database or logs can be split, there can be multiplepieces. Therefore, the otlset is the starting location within theprivate region where this piece of the database begins. Copyrepresents the copy of the database to which this piece belongs.

Multipathing ltdynamic multipathing is enabled and there are multiple paths to

Lnf orrna t i on the disk, this item shows information about the paths and theirstatus.

Lesson 2 Managing Devices Within the VxVM Architecture 2-7COi1yrlght;!':, 21)06 Symanter. Corporaton All (lall\S reserved

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Disk Types and Disk Formats

Disk types and formats include:auto indicates that when the vxconf igd daemon has been started. YxYMautomatically COli figures a disk accessrecord for the disk based on a list ofknown disk device addressesobtained trom the operating system. Auto-configured disks arc displayed with their type aud qualified by their format.For example, auto: cdsdisk indicates an auto-configured disk that isformatted as a cross-platform data sharing (CDS) disk that is suitable lormoving between different operating systems. This is the default format lormost disks on a system, hut not lor hoot. root, or swap disks.If a disk is automatically configured by YxYM as a simple or sliced disk, youwill seedisk types and formats, such as auto: simple and auto: sliced.auto:none indicates that the disk is not Iormaucd lor YxYM.cdsdisk indicates that the public and private regions are contiguous on thesame partition and suitable lor moving between different operating systems.sliced indicates that the public and private regions are separate partitions.none indicates that there an: no public or private regions on the disk.

VxVM Disk Types and Formats• auto: Automaticaffy configured by VxVM

auto: cdsdisk (Default for 4.x and higher)• auto:simple• auto: hpdisk (Only on HP-UX)• auto:none

• cdsdisk: Public and private regions are contiguous on thesame partition and suitable for moving between differentoperating systems.

• sliced: Public and private regions are on separate partitions.

• hpdisk: HP-UX specific disk format is used for system diskand before version 4.x.

• none: There are no public and private regions.Notes:

You can change the default format by using the vxdiskadmoption."Change/Display the default disk layouts" or in /etc/vx/disk.

Non-boot sliced disks can be converted to CDS disks by using thevxcdsconvert command.

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,a",VxVM Configuration Daemon

vxconfigd:Maintains the configuration databaseSynchronizes changes between multiple requests,based on a database transaction model:

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All utilities make changes through vxconfigd.

Utilities identify resources needed at the start of thetransaction.

Transactions are serialized, as needed.Changes are immediately reflected in all copies.

Does not interfere with access to data on diskMust be running for changes to be made to theconfiguration database

If vxconfigd is not running. VxVM operates, but configurationchanges are not allowed and queries of the database are notpossible.

The VxVM configuration daemon must be running in order for configurationchanges to be made to the VxVM configuration database. Ifvxconfigd is notrunning, VxVM operates properly. but configuration changes are not allowed andqueries of the database arc not possible.

The vxconf igd daemon synchronizes multiple requests and incorporatesconfiguration changes based on a database transaction model:

All utilities make changes through vxconf igd.

Utilities must identify all resources needed at the start of a transaction.Transactions arc serialized. as needed.Changes are immediately reflected in all copies of the configuration database.

The vxconf igd daemon does nut interfere with user or operating system accessto data on disk.

Controlling the VxVM Configuration Daemon

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2-9Lesson 2 Managing Devices Within the VxVM Architecture

VxVM Configuration Daemon

• vxconfigd reads the kernel log to determinecurrent states of VxVM components and updatesthe configuration database.

• Kernel logs are updated even if vxconfigd is notrunning. For example, upon startup, vxconfigdreads the kernel log and determines that a volumeneeds to be resynchronized.

• vxconfigd modes:- Enabled Normal operating state- Disabled Most operations not allowed

Booted Part of normal system startupwhile acquiring the boot disk group

vxconfigd Modes

vxconfigd reads the kernel log to determine current states ofVxVMcomponents ami updates the configuration database. Kernel logs arc updated evenifvxconfigd is not running. For example, upon startup, vxconfigd reads thekernel log and determines that a volume needs to be rcsynchronizcd.

vxconf igd operates in one of three modes:

EnabledEnabled is the normal operating mode in which most configuration operationsarc allowed. Disk groups arc imported. and Vx"M begins to manage devicenodes stored in / dev /vx/ dsk and / dev /vx/ rdsk.

Disabled

In the disabled mode, most operations arc not allowed. vxconf igd docs notretain configuration information lor the imported disk groups and docs notmaintain the volume and plcx device directories. Certain failures, mostcommonly the loss of all disks or configuration copies in the boot disk group,cause vxconf igd to enter the disabled state automatically.

Buotcd

The booted mode is part of normal system startup. prior to checking the rootfile system. The booted mode imports the boot disk group and waits tor arequest to enter the enabled mode. Volume device node directories arc notrnauuaincd, because it may not be possible to \I rite to the root file system.

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~mManaging the VxVM Configuration Daemon

Use vxdctl to control vxconfigd.vxdctl mode Displays vxconf igd statusvxdctl enable Enables vxconfigdvxdctl disable Disables vxcon f igd

vxdctl stop Stops vxconfigd

vxdctl -k stop Sends a kill - 9vxconfigd Starts vxconfigd

vxdctl license Checks licensingvxdctl support Displays version information

The vxdctl Utility

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vxconf igd is invoked by startup scripts during the boot procedure. To managesome aspects ofvxconf igd, you can use the vxdct 1 utility.

Displaying vxconfigdStatus

To determine whether the configuration daemon is enabled. you use the vxdct 1mode command. This command displays the status of the configuration daemon,If the configurauon daemon is not running. it must be started in order to makeconfiguration changes. Disk failures arc also configuration changes, but there isanother way of tracking them if the daemon is down (kernel logs).

Enabling vxconfigdIf vxc on f igd is running, but not enabled, you use vxdct 1 enable to enablethe configuration daemon. This command forces the configuration daemon to readall the disk drives in the system and to set up its tables to reflect each known drive.When a drive fails and the administrator fixes the drive. this command enablesYxYM to recognize the drive.

Disabling vxconfigdTo prevent configuration changes from occurring, you can disable the daemon byusing vxdctl disable.

vxconf igd records all commands executed. whether through the YEA or theCLI. These commands are stored in /var/adm/vx. The veacmdlog tilerecords YEA commands and the cmdlog tile records ell commands.

Lesson 2 Managing Devices Within the VxVM Architecture

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syrnantec

This host ID is used to ensure that two or more hosts that can access disks on ashared SCSI bus do not interfere with each other in their use of those disks. Thishost ID is important in the generation of unique ID strings that arc used internallylor stamping disks and disk groups.

The volboot liic also contains the name of the system-wide default disk group ifthis has been configured. If the boot disk is under V-xVM control, the vol bootfile also contains the name of the boot disk group to which the boot disk belongs.

Caution: Never edit the volboot file manually. If you do so. its checksum isim alidated.

The volboot File

/etc/vx/volboot contains:• The host 10that is used by VxVM to establish ownership of

physical disks .

• The values of defaultdg and bootdgif these valueswere set by the user

Caution: Do not edit volboot, or its checksum is invalidated.

To display the contents of volboot:vxdctl list

To change the host 10in volboot:vxdctl hostid newhostidvxdctl enable

To re-create volboot:vxdctl init llostid

Note: The hostid field in /etc/vx/valboot is not returned by theUNIX hostid command, but rather by the hostnamecommand.

Managing the volboot File

Viewing the Contents of volboot

To view the decoded contents of the vol boot file:

vxdctl list

volboot fileve rs i on : 3/1seqno: 0.1cluster protocol version: 70hostid: trainl


Curyroqlll lO[)6 Svm.sruec Curp'H,11I011 All nor.ts reserveo

symaniec

Device Discovery Layer (DOL)vxdiskconfig (Solaris only)vxdisk scandisksvxdctl enable

User process level

Device discovery is theprocess of locating andidentifying disksattached to a host.

Kernel process level

VxVM Kernel

Device discovery occursautomatically whenever youadd a new disk array.

Discovering Disk Devices

What Is Device Discovery?

Device discovery is the process of locating and identifying the disks that areaccessible to a host. YxYM 3.2 and later features. such as dynamic multipathing(DMP). depend on device discovery. Device discovery enables you to dynamicallyadd support for disk arrays from a variety of vendors without rebooting the system.

Discovering and Configuring Disk Devices

To dynamically discover new devices, use the vxdiskconf ig utility. Thisutility scans for disks that were added since YxYM's configuration daemon waslast started and dynamically configures the disks to be recognized by YxYM. Thevxdiskconf ig utility invokes OS utilities, such as devf sadmon Solaris, toensure that the OS recognizes the disks. vxdi skconf ig then invokes vxdct 1enable, which rebuilds volume node directories and the DMP internal databasetu reflect the new state of the system.

DOL enables YxYM to use more descriptive names when using enclosure-basednaming, for example. emcO_1 rather than Di sk_l.

Note: The vxdi skconf ig utility docs nut exist on IIP-UX.

Lesson 2 Managing Devices Within the VxVM Architecture 2-13Copynqbt ~~ 2006 Syrnantec Corporal Ion I\I! nqhts reserven

Adding Support for a New Disk Array

With V x VM version 3.1 and later. to add support for a new type of disk array thatis developed by a third-party vendor, you must add vendor-supplied libraries byusing plauorm-spccific package installation commands. The new disk array docsnot need to be connected to the system \\ hen the package is installed. You mayneed to scan tor new devices by issuing plauonn-spccilic commands. Theil runvxdctl enable to ensure that VxVM updates the device list.

Adding Disk Array Support

• To add support for a new type of disk array, add vendor-supplied libraries. For example:

pkgadd -d /edrom/pkgdir SEAGTda (Solaris)

swinstall -5 /edrom/depotdir SEAGTda (HP-UX)

installp -ae /edrom/pkgfile SEAGTda (AIX)rpm -ihv /edrom/pkgdir SEAGTda,rpm (Linux)

Scan for new devices:

vxdetl enable- This command invokes vxconfigd to scan lor all disk devices,

updates the device list, and reconligures DMP.- You do not need to reboot the host.

Note: VxVM supports many arrays "out-of-the-box."See vxddladm listsupport lor a complete list.

To remove support for a disk aITaY. you remove the vendor-supplied librarypackage by using the OS-spcci lie command. For example, to remove support lorthe SEAGTda disk array:

Sularis

Removing Support for a Disk Array

pkgrm SEAGTdaHP-UX

swremove SEAGTdaAIX

I.iIlUXinstallp -u SEAGTda

rpm -ev SEAGTda

Ir the arrays remain physically connected to thc host alter support has beenremoved. they arc listed in the OTHER_DISKS category. and the VOIUllh:S remainavailable.

2-14 VERITAS Storage Foundation 5. a for UNIX: Maintenance

Cooynght 2006 Symantec CorPOfil!lQf1 All rights reserved

svmantcc

You can use the vxdisk scandiskscommand to scanpart of the OS device tree, as follows:• Discover newly added devices previously unknown to VxVM:

vxdisk scandisks new

• Discover fabric devices:vxdisk scandisks fabric

• Scan for the specific devices:vxdisk scandisks device=cltldO,c2t2dO

• Scan for all devices except those that are listed:vxdisk scandisks !device=cltldO,c2t2dO

• Scan for devices that are connected to logical or physicalcontrollers:vxdisk scandisks ctlr=cl,c2

• Discover devices that are connected to the specified physicalcontroller:vxdisk scandisks pctlr=/pci@lf,4000/scsi@3/

Partial Device Discovery

VxVM supports partial device discovery where you can include or exclude sets ofdisks or disks attached to controllers from the discovery process. Partial devicediscovery reduces redundant discovery operations by scanning only a part of theOS device tree.

The vxdisk scandisks command rescans the devices in the OS device treeand triggers a DMP rcconfiguration. You can specify parameters to vxdi skscandisks to implement partial device discovery.

Lesson 2 Managing Devices Within the VxVM Architecture 2-15Ccpynqht r 2006 Svruantec Corporauon All nqtus reserved

Managing Multiple Paths to Disk DevicesThe dynamic multipathing (OMP) feature or Vx VM provides greater reliabilityand performance for your system by enabling path Iailovcr and load balancing.

Dynamic Multipathing (DMP)DMP: A method VxVM uses to manage two or morehardware paths to a single drive

(?!Il.......,ru ••• !!H:],( Fibre Channelswitche~/ j

Dynamic muhipathing is the method that VxVM usesto manage two or morehardware paths directing 1:0 to a single drive. VxVM arbitrarily selects one ofthetwo names and creates a single del ice entry. and then transfers data across bothpaths to spread the 1:0.

V,VM detects multipath systems by using the universal world-wide deviceidentifiers (WWD IDs) and manages mulupaih targcts. such as disk arrays. whichdefine policies for using 1I10rcIIJ:.lnone p.uh.

1=Host I• Mapped

==>by DMP

Single OMPMetanode

Benefits or DM P include:High availabitityDMP provides greater reliability using a path Iailovcr mechanism. When oneconnection to a disk is 1051. the system coni inucs to accessthe critical data overthe other sound connections 10 the disk until you replace the railed path.Improved performance

DMP provides greater I/O throughput by balancing the I/O load uniformlyacross multiple I/O paths to the disk device.

2-16

IfBcsiOILfBCBil~

rnn 1IIIIIIb~~~o;ure

LOiskis disk15 or disk27,dependingon the path.

What Is Dynamic Multipathing?

Benefits of DMP

Copvnqnt ;:; 2006 Syrnamec Corpcranon All rights reSf'rved


'symanlCC.

Types of Multiported Arrays

Active/Active I• Active/Passive If

I Path2

I PassiveI Path

+- (Secondary)

Pathl Path2 Pathl

ActivePath

(Primary)

ActivePath

ActivePath

Used for:• Load balancing• Path failover

Used for pathfailover only

What Is a Multiported Disk Array?

A multiported disk array is an array that can be connected to host systems throughmultiple paths. The two basic types of multiported disk arrays are:

Active/active disk arraysActive/passive disk arrays

For each supported array type, V.xVM usesa multipathing policy that is based onthe characteristics of the disk array.

Active/Active Disk Arrays

Active/active disk an'ays permit several paths to be used concurrently for 110.Withthese arrays, DMP provides greater I/O throughput by balancing the I/O loaduniformly across the multiple paths to the disk devices. If one connection to anarray is lost, DMP automatically routes I/O over the other available connections tothe array.

Active/Passive Disk Arrays

Active/passive disk arrays permit only one path at a time to be used for 1/0. Thepath that is used for I/O is called the active path. or primary path. An alternatepath, or secondary path. is configured for use in the event that the primary pathfails. If the primary path to the array is lost. DMP automatically routes I/O over thesecondary path or other available primary paths.

Lesson 2 Managing Devices Within the VxVM Architecture 2-17Copyright ." 2006 Symantec Ccrocranoo 1\11 nqt-ts reservec

syrnantec

Setting 1/0 Policies and Path Attributes

To change the 1/0 policy for balancing the 1/0 load acrossmultiple paths to a disk array or enclosure:vxdmpadm setattr enclosure enc name iopolicy=policy

• adaptive• balanced• minimumq

• priority• round· robin• singleactive

To set path attributes for a disk array or enclosure:vxdmpadm setattr path path_name pathtype=type

• active • primary• nomanual secondary• nopreferred • standby• preferred

Setting the 1/0 Policy for an Enclosure

Alter analyzing statistics. you can use the vxdmpadm setat tr command withthe iopolicy option to change the 1/0 policy for balancing the 110load acrossmultiple paths to a disk array or enclosure.

You can set policies loran enclosure (Iorcxumplc. HDSOI). for all enclosures olaparticular type (for example. HDS). or for all enclosures ora particular array type(AlA lor active.active. or Ail' for active/passive).

adapti ve automatically determines the paths that have the least delay andschedules I/O Oil paths that arc expected to curry a higher load.

balanced takes the track cache into consideration when balancing I/Oacrosspaths.

minimumq sends 110 on paths that have the minimum number of 1/0 requestsin the queue. This is suitable lor low-end disks or .IBODs where a signi Iicanttrack cache does not cxist.

priori ty assigns the path with the highest load carrying capacity as thepriority path.

round-robin sets a simple round-robin policy tor 1/0.

singleac ti ve channels liO through the single active path.

To display the current I/Opolicy:

vxdmpadmgetattr enclosure enclosure name iopolicy


Setting Path Attributes

You can set the following attributes of the paths to an enclosure or disk array byusing the command:vxdmpadmsetattr path path_name pathtype=type

active changes a standby path to active.nomanual restores the original primary or secondary attributes of a path.nopreferred restores the normal priority of the path.preferred [priori ty=N] specifies a preferred path and optionallyassigns a priority value to it. This indicates a path that is able to carry a higherI/O load. The priority value must be an integer greater than or equal to I.Larger priority values indicate a greater load carrying capacity.,,"ote: Marking a path as a preferred path does not change its I/O loadbalancing pol icy,primary assigns a primary path for an Active/Passive disk array.secondary assigns a secondary path for an Active/Passive disk array.standby marks a path as not available for normal I/Oscheduling. This pathis only invoked if there are no active paths available for 110.

See the 1'ERITAS 1'olume MOl1ager Administrator 's Guide and thevxdmpadm (1m) manual page for more information.


Copyr,ght s: 2006 Symantec Corporation All nqhts resr,rved

2-19

Displaying 1/0 Statistics for Pathssyrnantec

1. Enable the gathering of statistics:vxdmpadm iostat start [memory=sizeJ

2. Reset the I/O counters to zero:vxdmpadm iostat reset

3. Display the accumulated statistics for all paths:vxdrnpadrn iostat show all

cpu usage = 7952us

OPERATIONSper cpu memory = 8192b

BYTES AVG TIME(ms)PATHNAMEcOtOdO

c2t1l8dO

c3 t1l8dO

READSWRITES READSWRITES1088 557056 0

READS WRITES0.009542 0.000000

0.001194 0.000000

0.000000 0.000000

87

o44544

o• The displayed statistics can be filtered by path name, DMP

node name, and enclosure name.• You can also specify the number of times to display the

statistics and the time interval.

Displaying 1/0 Statistics for Paths

You can use the vxdmpadmiostat command to gather and display JiO statistics1'01' a specified DMP node, enclosure, or path.

The statistics that arc displayed arc the CPU usage and amount 01' memory pCI'CPU used to accumulate statistics. the number 01' read and write operations, thenumber ofblocks read and written. and the average time in milliseconds pc:r readand write opcrat ion.

The interval and count attributes may be used to specify the interval in secondsbetween displaying the I/O statistics. and the number of lines to be displayed. Theactual interval may be smaller than the value specified if insufficient memory isavailable to record the statistics.

2-20 VER/TAS Storage Foundation 5.0 for UNIX. Maintenance

Cunynqlu '<:U06 Swuarnec Corpcrauon All nqnts reserved

IPreventing DMP for a Device m;--------If an array cannot support DMP, you can preventmultipathing for the device by using vxdiskadm:

~~~en~ multipathing/s~press d~~ces ~rom VX~~S Vie~

Allow multipathing/Unsuppress devices from VxVM's Vie~

List currently suppressed/non-multipathed devices

I Warning: IIf you do not prevent DMP for unsupported arrays:

Commands like vxdisk list show duplicate sets of disks asONLINE, even though only one path is used for 1/0.

Disk failures can be represented incorrectly.

Preventing Multipathing for a Device

If you have an array that cannot support the use ofDMP, or if you want to useSun's Alternate Pathing driver with Vx VM. you can suppress DI'vIP for some or alldevices by using the vxdiskadm menu. Suppressing DMP for a device preventsmultipathing without removing the DMP layer.

It is important for you to suppress DMP for devices that do not support OM!'. Ifyou do not prevent DMP for unsupported arrays:

A VxVM command, such as vxdisk list, shows duplicated sets of disks asONLINE for each path, even though the command is only using one path for110.

Disk failures can be represented or displayed incorrectly by VxVM if DM!' isrunning with an unsupported, unsuppressed array.

To manage the devices that participate ill DMP. you call use vxdiskadm.


Copyright '$ 2()06 Syrnantec Corporation 1\11nonts reserved

2-21

syrnanrec

Preventing DMP for a DeviceWhen you select the option to prevent multipathing in thevxdiskadm main menu, you have these choices:

,

I,i. suppre-;;'';ii' paths th;ough a controller from ]. VxVM's view

Suppress a path from VxVM's view

Suppress disks from VxVM's view by specifying aVID:PID combinationSu resa all but one aths to a di.~s~k ~Prevent multipathing of all disks on a controller

l __ .:::by£-V:;X::.VM:.::.. •• _Prevent multipathing of a disk by VxVMPrevent multipathing of disks by specifying aVID:PID combinationList currently suppressed/non-multipathed devices

Similar choices exist when you reinclude devices for DMP.

Excluding Devices from Multipathing

When you select the option to prevent mulupathing in the vxdi skadmmainmenu, the Exclude Devices submenu is displayed.

Both of the following options send the command vxdmpadmdi sable to thekernel:

The option "Suppress all paths through a controller from VxVM's view"coutinucs to allow the I/O to use both paths internally. Aller a reboot, vxdisk1i s t dues not show the suppressed disks.

"Prcvcnt multipathing of all disks on a controller by VxVM" docs not allowthe l.O to use intcrnal muliipathiug. The vxdisk list command shows alldisks as ONLINE. This option has no effect on arrays that arc not performingdynamic multipathing or that do not support VxVM DM!'.

Including Devices for Multipathing

Fur previously excluded devices. if you later decide that you want to rcincludc thedevice in muluparhing. then you select the vxdiskadm option "Allowmulripathing.Unsupprcss dcv iccs lrom VxVM's view." A similar set of options isavailable in the Include Devices submenu.

2-22Copvnqht " 20!)6 Syrnantec Corpo-auon All r'lj~lls reserved

VERITAS Storage Foundation 5.0 for UNIX.' Maintenance

You can disable 1/0 to a controller to performmaintenance, for example:• To replace a system board• To test path failover

Use the following commands:

• To disable 1/0 to a particular controller:vxdmpadm disable ctlr=ctlI~name

• To disable 1/0 to a particular enclosure:vxdmpadm disable enclosure=enc_name

• To reenable 1/0 to a particular controller:vxdmpadm enable ctlr=ctlr_name

In VEA: Select Actions->Disable (or Actions->Enable)and complete the associated dialog box.

symantcc.

Enabling or Disabling 1/0 to a Controller

By disabling 110 to a host disk controller. you can prevent DMP from issuing 110through a specified controller. You can disable I/O to a controller to performmaintenance on disk arrays or controllers attached to the host. For example. whenreplacing a system board. you can stop all 110 to the disk controllers connected tothe board before you detach the board.

For active/active disk arrays. when you disable [/0 to one active path, all 1'0shifts to other active paths.

For active/passive disk arrays. when you disable I/O to one active path. all 110shifts to a secondary path or to an active primary path on another controller.

You cannot disable the last enabled path to the root disk or any other disk.On IIP-UX. you can disable the last enabled path to any other disk (without usingthe -f (force) option).

When you disable 1/0 to a controller. disk. or path. you override the DMP restoredaemon's ability to reset the path to ENABLED.

When you enable I/O to a controller:

For active/active disk arrays. the controller is used again tor load balancing.

For active/passive disk arrays. the operation results in tailback of I/O to theprimary path.

Enablingor Disablinga Controller: VEA

To disable or enable a controller in YEA. select the controller. select Actions>Disablc or Actions >Enable. and complete the associated dialog box.

Copvnont 'f 20D6 Svmamer- Corporation All nqhts reservec

2-23Lesson 2 Managing Devices Within the VxVM Architecture

The [)MP restore daemon is an internal process that monitors DMP paths andautomatically enables paths that were previously disabled due to hardware failuresafter the paths arc back online.

Controlling the Restore Daemon

The DMP restore daemon is an internal process thatmonitors DMP paths. To check its status:

vxdmpadm stat restoredThe number of daemons running: 1The interval of daemon: 300The policy of daemon: check_disabled

To start the [)MP restore daemon, you use the start restore option in thevxdmpadm command.

vxdmpadm start restore [interval=intervall[policy=check_disabledlcheck_alll

The restore daemon unalyzcs the health olpaths every interval seconds. The:default interval is 300 seconds. Decreasing the interval can adversely affectperformance.

You can specify one oftwo types olpolicics:If the policy is check_disabled, the restore daemon checks the health ofpaths that were previously disabled due to hardware failures and revives themif they arc back online.

If the policy is check_all, the restore daemon analyzes all paths in thesystem, revives the paths that arc back online, and disables the paths that arcinaccessible.

interval: Frequency of analysis (default: 300seconds)check disabled: Only checks disabled paths (default)

To change daemon properties:• Stop the DMP restore daemon:

vxdmpadm stop restore

• Restart the daemon with new attributes:vxdmpadm start restore interval=400policy=check_all

I check all: All paths are checked.

Controlllnq Automatic Restore Processes

Starting the DMP Restore Daemon

The default policy is check_disabled.


Copyr.qnt 2006 Svmantec Corpoeanon All nqhts reservec

symantcc.

Lesson Summary

• Key PointsThis lesson described components in the VxVMarchitecture and the device discovery process anddescribed how to administer dynamic multipathing.

• Reference Materials- VERITAS Volume Manager Administrator's Guide- VERITAS Storage Foundation Release Notes- VERITAS Volume Manager Hardware Notes

svmantcc

Labs and solutions for this lesson are located on the following pages:

Appendix A provides complete lab instructions. 'Tab 2: r..LlIu~ing Dc\ ices \\11I:il1the Y \ \'\ I :\rL'ililccrllll'," 1',1ic\' ,\_1,1

Appendix B provides complete lab instructions and solutions, "I ah :: '.;,'!u!iU!h:M:llll1:2i!l)1 Dcvic •.> Withl11 the \'\ \'\1 .vnhirccturc.' pagl 11·: I

Lab 2

Lab 2: Managing Devices Within the VxVMArchitectureIn this lab, you explore the VxVM tools used tomanage the device discovery layer (DOL) anddynamic multipathing (DMP). The objective ofthis exercise is to make you familiar with thecommands used to administer multipatheddisks.


Lesson 2 Managing Devices Within the VxVM Architecture 2-25


CllJlYfI!-lot!' 2006 Symamec Cor{lor;;llul"' All fights reserved

Lesson 3

Encapsulation and Rootability

'symankc.

Lesson Introduction• Lesson 1; Maintaining Data

Consistency• Lesson 2: Managing Devices Within

the VxVM Architecture

• ~~~~~~i~~yEnCapsulati::_a.:~~ ._~



Overview

symantec.



Topic 1: Placing the Boot Place the boot disk under VxVMDisk Under VxVM Control control.

..

Topic 2: Creating an Create an alternate boot disk byAlternate Boot Disk mirroring the boot disk that is under

VxVM control.Topic 3: Removing the Remove the boot disk from VxVMBoot Disk from VxVM control.Control


Placing Disks with Data Under VxVM Control

• On Solaris, encapsulation is the process ofconverting partitions into volumes to bringthose partitions under VxVM control.

• On HP-UX, conversion is the process ofenabling LVM physical volumes to be usedbyVxVM.

SOlarisl HP-UXI

Placing the Boot Disk Under VxVM Control

What Is Encapsulation or Conversion?

symantcc.

On Solaris. encapsulation is the process of converting partitions into volumes tobring those partitions under VxVM control. On IIP-UX, conversion is the processof enabling LVM physical volumes to be used by Vx VM, A Her a disk has beenencapsulated or converted. the disk is handled like an initialized disk,

Placing Disks with Data Under VxVM Control: Solaris

Encapsulation is the process of converting partitions into volumes to bring thosepartitions under Vx Vlvl control. For example. if a system has three partitions onthe disk drive and you encapsulate the disk to bring it under VxVM control. therewill be three volumes ill the disk group,

Solaris Encapsulation Requirements

Disk encapsulation cannot occur unless these requirements arc met:Partition table entries must be available on the disk for the public and privateregions, During encapsulation. you are prompted to select the disk layout. Ifyou choose a CDS disk layout. then only one partition is needed. However, ifencapsulation as a CDS disk fails. you can specify that a sliced layout be usedinstead, in which case you will need two free partitions,The disk must contain an s2 slice that represents the full disk (The s2 slicecannot contain a tile system),2048 sectors of unpartitioned free space. rounded up to the nearest cylinderboundary. must be available. either at the beginning or at the end of the disk,

Lesson 3 Encapsulation and Rootability

COPYright ~~ 2006 Syrnanter- Corporaucn All nqms reserved

3-3

Encapsulateddata disk

,---._,_ Private region -......--~1~-·-;1----+I homev~ engvol

eng --- '-----

acct -----_'[~ jBW~--.---~~dist ~~

Solaris: Encapsulating a Data Disk

vxdiskadm:

"Encapsulate one or more disks"

Follow the prompts by specifying:

Name of the device to add

Name of the disk group to which the disk will be added

vxencap:

/etc/vx/bin/vxencap -g diskgroup access name

Run the script:

/etc/init.d/vxvm-reconfig access name

Solaris: Reversing the Encapsulation ProcessLimitations:

There arc no tools to help with uncncapsulation. (The system disk is anexception to this.)

Encapsulation should not be attempted if:

Volume layouts have been altered in any way (for example, hotrclocauon ).

Volumes have mirrors.

The disk has been used for parts of other volumes.

The partition table before encapsulation is stored in:

/etc/vx/reconfig.d/disk.d/device/vtocFollow this procedure to encapsulate:

a Stop applications.

b Remove volumes on the disk and take the disk out of VxVM control.

c Re-create thc partition table as provided ill the stored vtoc tile.d Manually modify /etc/vfstab (itnecessary).

e Reboot or manually mount the partitions and start applications.


CIJPynghl;: 2006 Svmautec Corrorauou All nqtus reservecr

Placing Disks with Data Under VxVM Control: HP-UX

Conversion is the process of enabling LVM physical volumes to be used byVxVM. You can convert:

Unused physical volumesPhysical volumes in volume groups

UnusedPhysicalVolume ~ .•..... - ...'..•... '.U

[VXVM Disk Group Ii,y .-k_·4JWJi8L'!£&;;.'*~#Jiik" ~. '

LVM Physical Volumes VxVM Disks

HP-UX: Limitations of LVM Conversion

LVM configurations that you cannot convert to VxVM include:A volume group with insufficient space for mctadataA volume group containing the root volumeA volume group containing the lusr file systemA volume group with any dump or primary swap volumesA volume group disk used in ScrviceGuard clustersA volume group with any disks that have bad blocks

HP-UX: Converting Unused Physical Volumes1 View group membership information to ensure that then: is no data on the

LVM disk:pvdisplay disk_namepvdisplay /dev/dsk/c4tldO

2 Remove LVM disk information:pvremove disk_namepvremove /dev/dsk/c4tldO

3 Initialize the disk for VxVM use,

Lesson 3 Encapsulationand Rootability 3-5Copyright? 2006 Svrnantar Corporation All nqtus reserved

UP-LJX: Cunverting Volume Groups

vxvmconvert

Volulne Manager SUPPOI"( OperationsMenu: Volume Manager/LvM_Conversion

listlistvg

Allalyze LVM Volume Groups for Conversionconvert LVM Voillme G~oups to VxVMRoll back tram VxVM to LVMList disk informatioIlList LVM Volume Group inforntation

??Display help about menuDisplay help about the menuing systemEx i t f iorn menusq

Select an operation to perfOrl":

UP-LJX: Conversion PrOC('SS(LV'I to VxV'I)

1 Identify volume groups.2 Analyze volume groups.3 l3ack lip LV M data.4 Plan for new names.5 Stup applications.6 Unrnount the file system.7 Convert volume groups.8 Make name changes.9 Restart applications.10 Customize the configuration.

IIP-LJX: Restoring LVi\! Volume Group Cunfiguration

Roll Back Using vxvmconvert

Full LVM Restoration fur the Volume Group

LVM Volume Group VxVM Disk Group

LVM Physical Volumes VxVM Disks


CIlPVflljlllL 2006 Syruantec Corpnratrcu All r.ghts reserved

HP-UX: Roll Back Using vxvmconvert

vxvmconvert Option 3, roll hack from \',\',\1 to 1.\',\1

Select Volume Group(s) to rollback:[<pattern-list>,all,list,listvg,q,?) vg08

Roll back this Volume Group? [y,n,q,?) (default: y)

Rolling back LVM configuration records for Volume Group vg08

Selected Volume Groups have been restored.

Hit RETURN to continue.

Rollback other LVM Volume Groups? [y,n,q,?) (default: n)

UP-lIX: Full L\'l\l Restoration for the Volume Group

To restore LVM internal data:mkdir /dev/vol group_namemknod /dev/vol_group_name/group c 64 oxoeoooovxdg destroy diskgroup

For each disk in the volume group:vxdiskunsetup disk_namevgcfgrestore -F -f pathname/filename raw_device_namevgimport -s -m pathname/mapfilename vol grp_nameraw device namevgchange -a y vol group_name

To restore user or application data:mount -F fstype /dev/vol group_name/lvname /mount po~ntfrecover -r -f /dev/rmt/cOtOdOBEST

------------------------------------------------------


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3-7

What Is Rootability?Rootability is the process of placing the root file system,swap device, and other file systems on the boot disk underVxVM control.On Solaris, you encapsulate the system disk.

Encapsulatedboot disk II

Partitions are mapped to subdisksthat are used to create the volumes

¥ that overlay the original partitions.

W:---""Sii1l Private region1I\r---"':!III / ------<\1:? -?i1/usr----------~====~-'------

~-----~;::;~ ~

Note: Only sliced layout is allowed.

What Is Rootability?

Rooiability is the process ofplncing the root file system. swap device, and otherfile systems on the boot disk under VxVM control.

Solaris

On Solaris, VxVM converts existing partitions ofthe boot disk into VxVMvolumes. The system can then mount the standard boot disk file systems (that is./, /usr. ami so 011) from volumes instead of disk partitions.

Boot disk encapsulation has the same requirements as data disk encapsulation, butrequires two Ircc partitions (for the public and private regions). Whenencapsulating the boot disk. you can create the private region from tile swap area,which reduces the swap area by the size otthc private region. The private region iscreated at the beginning of the swap area. and the swap partition begins onecylinder from its original location.

When creating new boot disks, you should start the partitions on the new hootdisks on the next cylinder beyond the 2048 default used tor the private region.

ur-ux011 HP-UX. rootability is carried out by creating a coJlY of the system disk onanother VxVM disk.

Copvnqhr 'C' 20U6 Svmantec Co-poianon 1\11nqnts reserved

VERITAS Storage Foundation 5.0 for UNIX: Maintenance3-8

symantec.

Why Put the Boot Disk Under VxVM Control?On Solaris:• You should encapsulate the boot disk only if you plan

to mirror the boot disk.

• Benefits of mirroring the boot disk:-Enables high availability-Fixes bad blocks automatically (for reads)-Improves performance

• There is no benefit to boot disk encapsulation for itsown sake. You should not encapsulate the boot disk ifyou do not plan to mirror the boot disk.

On HP-UX:Single storage virtualization tool for system disk anddata disks.

It is highly recommended that you encapsulate and mirror the boot disk. Some ofthe benefits of encapsulating and mirroring root include:

High availability

Encapsulating and mirroring root sets up a high availability environment forthe boot disk. Ifthe boot disk is lost. the system continues to operate on themirror disk.

Bad block revecturingIf the boot disk has bad blocks. then YxYM reads the block from the other diskand copies it back to the bad block to fix it. SCSI drives automatically fix badblocks on writes, which is called bad Mock rvvcctoring.

Improved performance

By adding additional mirrors with different volume layouts. you can achievebetter performance. Mirroring alone can also improve performance if the rootvolumes arc performing more reads than writes, which is the case on manysystems.

Why Put the Boot Disk Under VxVM Control?

When Not to Encapsulate Root

If you do not plan to mirror root. then you should not encapsulate it. Encapsulationadds a level of complexity to system administration, which increases thecomplexity of upgrading the operating system.


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3-9

Limitations of the VxVM Boot Disk

• Placing the boot disk under VxVM control addssteps to OS upgrades on Solaris platform.

• A system cannot boot from a boot disk that spansmultiple devices.

• Never grow or change the layout of boot diskvolumes. These volumes map to a physicalunderlying partition on disk and must becontiguous.

HP-UX Note: HP-UX supports OS installations on aVxVM disk. However, the version of VxVM that isinstalled from the HP-UX installation media for 11iv2is 3.5.

Limitations of the VxVM Boot Disk

A system cannot boot from a boot disk that spans multiple devices.

You should never expand or change the layout of boot volumes, No volumeassociated with an encapsulated boot disk (r oot.vo l , usr. var. opt. swapvoL,and so on) should be expanded or shrunk. because these volumes map to a physicalunderlying partition on the disk and must be conuguous,

If you attempt to expand these volumes. the system can become unbootublc ifitbecomes necessary to reven back to slices in order to boot the system. Expandingthese volumes can also prevent a successful OS upgrade. and a fresh install can berequired.

Solaris

Additionally. the upgrade_start script (USedin upgrading VxVM to a newversion) may Jail.

Note: You can add a mirror ofa dillcrcut layout, but the mirror is not bootablc.


Copyright! 2006 Symantec Corporation All uqhts reserved

symantec.Th-File System Requirements: Solaris Only

For root, usr, var, and opt volumes:• Use UFS file systems. (VxFS is not available until later in the

boot process.)

• Use contiguous disk space. (Volumes cannot use striped,RAID-5, concatenated mirrored, or striped mirrored layouts.)

• Do not use dirty region logging on the system volumes. (Youcan use DRl for the opt and var volumes.)

For swap volumes:• The first swap volume must be contiguous, and, therefore,

cannot use striped or layered layouts.

• Other swap volumes can be noncontiguous and can use anylayout. However, there is an implied 2-GB limit of usable swapspace per device for 32-bit operating systems.

HP.UXI

File System Requirements for Root Volumes: Solaris Only

To boot from volumes. follow these requirements and recommendations for thefile systems on root volumes:

For the root. usr. var. and opt volumes:

Use lJFS file systems: You must use UFS file systems for these volumes.because the VERITAS File System (VxFS) package is not available until laterin the boot process when the scripts run in /etc/rc2.d (multiuser mode).

Use contiguous disk space: These volumes must be located in a contiguousarea on disk. as required by the OS. For this reason. these volumes cannot usestriped. RAID-S. concatenated mirrored. or striped mirrored layouts.

Do not use dirty region logging for root or uar: You cannot use dirty regionlogging (DRL) on the root and usr volumes. If you attempt to add a dirtyregion log to the root and usr volumes. you receive an error.

Note: The opt and var volumes call use dirty region logging.

Swap Space Considerations: If you have swap defined, then it needs to becontiguous disk space. The first swap volume (as listed in the /etc/vEstabtile) must be contiguous and. therefore. cannot use striped or layered layouts.

Additional swap volumes can be noncontiguous and can use any layout.

Note: You can add noncontiguous swap space through VxVM. However,Solaris automatically uses swap devices in a round-robin method. which mayreduce expected performance benefits of adding striped swap volumes.

For 32-bit operating systems. usable space per swap device is limited to 2 GB.For M-bit operating systems. this limit is much higher (up to :zi,,l - I bytes).

lesson 3 Encapsulation and Rootability

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3-11

Volume Requirements: HP·UX

All volumes on the root disk must be in thc disk group that you choose to be thebootdg disk group.

The names otthc volumes with entries in the LIF LABEL record must bestandvol, rootvol, swapvol, and dumpvol (ifpresent). The names ofthevolumes for other file systems on the root disk arc generated by appending vol tothe name of their mount point under /.

Any volume with an entry in the LI F LABEL record must be contiguous. Thcvolume can have only one subdisk. and it cannot span to another disk.

The root vol and swapvol volumes must have the special volume usage types,root and swap respectively.

Only the disk access types auto with hpdisk and simple formats arc suitable1(lJ" use as Vx VM root disks, root disk mirrors, or as hot-relocation spares for suchdisks.

The volumes on the root disk cannot use dirty region logging (DRL).

3-12 VERITAS Storage Foundation 5.0 for UNIX: Mamtenance

Copyright 2006 Svmautec Corroranon 1\11nylliS reserve-s

Before Placing the Boot Disk Under VxVM ControlPlan your rootability configuration:

Plan your rootabjlltv conflguration. bootdg is a system-wide reserved diskgroup name that is an alias for the disk group which contains the volumes that arcused to boot the system. When you place the boot disk tinder VxVM control.VxVM sets bootdg to the appropriate disk group. You should never attempt tochange the assigned value nfbootdg: doing so may render your systemunbooiable. An example configuration is to place the boot disk into a disk groupnamed sysdg. and add at least two more disks to the disk group: one for a bootdisk mirror and one as a spare disk. VxVM then sets bootdg to sysdg.

Solaris

Encapsulated Boot diskboot disk mirror

Spare disks

Enable boot disk aliases. On Solaris. before encapsulating your boot disk. set theEEPROM variable use -nvramrc? to true. This enables VxVM to takeadvantage of boot disk aliases to identify the mirror of the boot disk if areplacement is needed. If this variable is set to false. you must determine whichdisks are bootable yourself

On Solaris, set this variable to true as follows:

On Solaris:Enable boot disk aliases:eeprom "use-nvramrc?=true"

• Record the layout of the partitions on the unencapsulated boot diskto save for future use.

On HP-UX:Set the primary or alternate boot path from the boot menu or from thecommand line:Main Menu: Enter command or menu: co pa alt pathsetboot -p primary_path -a alternace __path

Save the LVM volume group configuration for vgOO.

Before Placing the Boot Disk Under VxVM Control

eeprom "use-nvramrc?=true"

Save the layout of partitions before you encapsulate the boot disk. Forexample. on Solaris. you can use the prtvtoc command to record the layout ofthe partitions on the unencapsulated boot disk (/ dev / rdsk/ cO t OdOs2 in thisexample):

prtvtoc /dev/rdsk/cOtOdOs2

Record the output from this command fur future reference.


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3-13

Placing the Boot Disk Under VxVM Control: Solarissymantcc

vxdiskadm:"Encapsulate one or more disks"

To encapsulate one or more disks, follow theprompts by specifying:

• Name of the device to add

• Name of the disk group to which the disk will be added

• Sliced disk format (The boot disk cannot be a CDS disk.)

vxencap:/etc/vx/bin/vxencap -g diskgroup \

-c diskgl'oup#=access_name

Run the script:/ etc/ ini t. d/vxvm-reconfig access name

HP.ux.1

Placing the Boot Disk Under VxVM Control

Encapsulating the Boot Disk: Solaris

vxdiskadm on Solaris

You cun use vxdi skadm fur encapsulating data disks as well as the boot disk. Toencapsulate the boot disk:

From the vxdiskadm main menu, select the "Encapsulate one or more disks"option.

2 When prompted. specify the disk device name ofthe boot disk. lfyou do notknow the device name ofthe disk to be encapsulated. type list at the promptfor a complete listing ofavailable disks.

3 When prompted, specify the name of the disk group to which the boot disk willbe added. The disk group docs not need to already exist.

4 When prompted. accept the default disk name and confirm that you want toencapsulate thc disk.

5 I f you arc prompted to choose II hcthcr the disk is to be formatted as a CDSdisk that is portable between different operating systems. or as a nonportablcsliced disk, then you must select sliced. Only the sliced format is suitable loruse with root. boot, or swap disks.

6 When prompted, select the default private region size. vxdiskadm thenproceeds to encapsulate the disk.

7 A message confirms that the disk is encapsulated and states that you shouldreboot your system at the curlicxt possible opportunuy.

3-14 VERITAS Storage Foundatioll5.0 for UNIX: Maintenance

C()l'ynyl'l 2006 Svtuantec Corpcrauon All rlyhts ff)served

vxencapon Solaris

The vxencap script identifies any partitions on the specified disk that could beused for file systems or special areas such as swap devices, and then generatesvolumes to cover those areas on the disk.

If the file system if unmounted. no reboot is necessary. If the file system ismounted, the system reboots immediately.

For more specific information on using the vxencap command. see the manualpages.

Creattng a VxVl\1 Boot Disk from an LVI\1 Boot Disk: HP-liX

The vxcp_1vmroot command sets tip a VxVM root disk.The command should be executed at inir level I {single user model./\ bootable mirror can also be created at the same time.A user-specified disk is initialized as a VxVM root disk with therootdisk## disk name.

The following example shows how to set up a VxVM root disk on cOt IdO and itsmirror on c1t4dO:

/etc/vx/bin/vxcp Ivrnroot -g dg -m clt4dO -v -b cOtldO

This process can be accomplished in two steps. as follows:/etc/vx/bin/vxcp Ivrnroot -g dg -v -b cOtldO

/etc/vx/bin/vxrootmir -g dg -v -b clt4dO-v: verbose- b: set primary and alternate hoot paths 10 the given devices

Lesson 3 Encapsulation and Rootabitity 3-15

Solaris

syrnantec

After Placing the Boot Disk Under VxVM Control

After boot disk encapsulation, you can view operatingsystem-specific files to better understand theencapsulation process.

Solaris:• VTOC• fete/system• /ete/vfstabLinux:• /ete/fstab

HP-UX: (Boot up on the VxVM boot disk to see the differences.)• /etc/fstab• /stand/bootconf

SolarisI Linux IAfter Placing the Boot Disk Under VxVM Control

Viewing EncapsulatedDisks

To better understand encapsulation ofthe boot disk, you can examine operatingsystem files lor the changes made by the VxVM root encapsulation process,

Alter encapsulating the boot disk. if you view the VTOC, you notice that Tag 14 isused for the public region, and Tag 15 is used lor the private region. The partitionslor the root. swap,US1', and var partitions arc still on the disk, unlike on datadisks where all partitions an: removed, rile boot disk is a special case. so thepartitions arc kept.

/I prtvtoc /dev!rdsk!cOtOdOs2 VTOC I* First Sector Last* Partition Tag Flags sector Coun t Sector edount. ...

0 2 00 0 4916016 49160151 3 01 4916016 2040256 69642112 5 00 0 11801280 118012193 14 01 0 11801280 118012194 15 Ot 11198256 3024 118012196 4 00 6964212 4301136 112654011 1 00 11265408 4505160 1~111161

As part olthc root encapsulation process. the fete/system file is updated toinclude intormauun that t..:lls VxVM to boot lip on the encapsulated volumes:

rootdev:/pseudo/vxio.O:O

3-16Copynyht r. 2006 Svruauter. Coeroranon All f'ghlS reserved


set vxio:vol rootdev is volume=l

VxVM also updates the /etc/vfstab tile to mount volumes instead ofpartitions.

r------------ ...---.---------------------i #deviceI #to mount

Ii Idevlvxldsklbootdg/swapvolI/devlvxldsklbootdg/rootvoli Idevlvxldsklbootdg/usr!

device mount FS fsck mountto fsck !;f;t~bl point type pass at boot

swap noIdevlvxlrdsklbootdg/rootvol ufs no/devlvxlrdsklbootdg/usr lusr ufs no

Linux

After you encapsulate the boot disk, you can view the changes in the etc/fstabtile.

Lesson 3 Encapsulation and Rootability 3-17Copyrlght:~ 2006 Symarnar CmpOf'lIIOIl All rlqtJts reve-veo

syrnantec.

Creating an Alternate Boot DiskRequirements:o An alternate boot disk is a mirror of the entire boot

disk. An alternate boot disk preserves the bootblock in case the initial boot disk fails.

o The requirements for creating an alternate boot diskare that:- The boot disk is under VxVM control.- Another disk is available with enough space to

contain all of the boot disk partitions.- All disks are in the boot disk group.

o The root mirror places the private region at thebeginning of the disk. The remaining partitions areplaced after the private region.

Solaris I HP.UXI

Creating an Alternate Boot Disk

Creating an Alternate Boot Disk: VEA1 Select a disk that is at least as large as the boot disk. and add the disk to the

boot disk group.

2 In the main window. highlight the boot disk. and then select Acrions=-c-MirrorDisk.

3 In the Mirror Disk dialog box. verify the name of the boot disk. and specify thetarget disk to use as the alternate boot disk.

4 Click Yes in the Minor Disk dialog box to complete the mirroring process.

5 Aller the root mirror is created. verify that the root mirror is booiablc.

Creating an Alternate Boot Disk: vxdiskadm1 Select a disk that is at least as large as the boot disk. and add the disk to the

boot disk group.

2 In the vxdi skadm main menu. select the "Mirror volumes on a disk" option.

3 When prompted. specify the name of the disk containing the volumes to bemirrored (that is. the name of the boot disk).

4 When prompted. specify the name of the disk to which the boot disk will bemirrored.

5 A summary of the action is displayed. and you arc prompted to confirm theoperation.

6 Aller the root mirror is created. verify that the root mirror is bootablc.


Copyrly~ll_~ 20U6 S}'nl,-lnl.-H Corporation All nqhls reserved

Creating an Alternate Boot Disk: CLI for Solaris1 Select a disk that is at least as large as the boot disk, and add the disk to the

boot disk group.

2 To create a mirror for the root volume only, use the vxrootmir command:

vxrootmir alternate diskwhere al ternate_disk is the disk name assigned to the other disk.

vxrootmir invokes vxbootsetup (which invokes installboot). so thatthe disk is partitioned and made bootable. (The process is similar to usingvxmirrorandvxdiskadm.)

3 To mirror all other concatenated, nonmirrored volumes on the primary bootdisk to your alternate boot disk, you can use the command:

vxmirror boot disk alternate disk- -4 Other volumes on the boot disk can be mirrored separately using vxassist.

For example, if you have a /home file system on a volume homevol, you canmirror it to al terna te_ disk using the command:

vxassist mirror homevol alternate disk(I' you do not have space for a copy ofsome of these file systems on youralternate boot disk, you can mirror them to other disks. You can also span orstripe these other volumes across other disks attached to your system.

5 After the root mirror is created, verify that the root mirror is bootablc.

You can also use the vxbootsetup command. The vxbootsetup utilityconfigures physical disks so that they can be used to boot the system.

Note: Before vxbootsetup is called to configure a disk, mirrors of the root.swap, /usr and /var volumes (if they exist) should be created 011 the disk.

To set up system boot information on a YxYM disk, type:

/etc/vx/bin/vxbootsetup

Creating an Alternate Boot Disk: CLI for HP-UX

To mirror the system disk:

vxrootmir -v -b alternate disk

Alternatively, to set up the system boot information and to mirror individualvolumes manually:

vxdisksetup -iB alternate_disk format=hpdisk

vxdg -g bootdg adddisk rootdisk##=alternate_disk

vxassist -g bootdg mirror standvol dm:rootdisk##

vxvmboot -v /dev/rdsk/alternate_disk

lesson3Encapsulation and Rootability

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3-19

Boot Disk Error Messages

Stale root volume Ivxvm: vxconfigd: Warning: Plex rootvol-Ol forroot volume is stale or unusable

, Fail~d startup Jvxvm: vxconfigd: Error: System startup failed:

;.Root plex not valid Ivxvm: vxconfigd: Error: System boot disk doesnot have a valid root plex

Please boot from one of the following disks:Disk: diskOl Device: cOtldOsO

Alternate boot disks are listed. I

syrnantec.

Possible Boot Disk ErrorsRoot plex is stale or unusable

vxvm:vxconfigd: Warning: Plex rootvol-Ol for rootvolume is stale or unusableSystem startup failed

vxvm:vxconfigd: ERROR: System startup failedSystem boot disk does 1I0t have a valid root plexvxvm:vxconfigd: ERROR: System boot disk does not have avalid root plexPlease boot from one of the following disks:Disk: diskname Device: device ...

In the third message, alternate boot disks containing valid root mirrors arc listed aspart of the error message. Try to bout from one of the disks named in the errormessage.

You may be able to boot using a device alias for onc of the named disks. Forexample. use this command:

ok> boot vx-disk name

Copynght ~ 2D06 Syruantec Corporation All r-yhls reserved


A:..!Booting from an Alternate Mirror: Solaris

To boot the system using an alternate boot disk afterfailure of the primary boot disk:1. Set the eeprorn variable use-nvramrc? to true:

syrnantec

ok> setenv use-nvramrc? trueok> reset

This variable must be set to true to enable the use ofalternate boot disks.

2. Check for available boot disk aliases:ok> devaliasvx-rootdisk Output displays the name of thevx-diskndme boot disk and available mirrors.

3. Boot from an available boot disk alias:ok> boot vx-disk_name

Booting from an Alternate Mirror: Solaris

If the boot disk is cncapsularcd and mirrored. you can use one of its mirrors to bootthe system if the primary boot disk fail>.

Booting from an Alternate Mirror: HP-UX

To boot the system using an alternate boot disk after failure of the primary bootdisk:

Interrupt the automatic boot process:To discontinue, press any key within 10 seconds.

2 Check the alternate boot disk path:Main Menu: Enter command or menu> co alt paVerify that the alternate disk path is the one you want to boot from. Ifnot, set itlIsing the co a 1 t pa path command.

3 1300tusing the alternate disk path:Main Menu: Enter command or menu> bo altInteract with IPL (Y, N, or Cancel)? n

Lesson 3 Encapsulation and Roolability 3-21Copyngl\l ,(.) 201)6 Svmantec Corncrauon All nqhts reserved

syrnaruec.

Removing the Boot Disk from VxVM Control: Solaris

• To unencapsulate a boot disk, use vxunroot.

• Requirements:Remove all but one plex of rootvol, swapvol, usr, var,opt, and home.

• Use vxunroot when you need to:- Boot from physical system partitions.- Change the size or location of the private region on the

boot disk.

H~.uxl

Removing the Boot Disk from VxVM Control

Thevxunroot Command: Solaris

To couvert the root file systems back to being accessible directly through diskpartitions instead or through volume dcv ices. you use the vxunroot utility. Otherchanges that were made to ensure the booting or the system from the root volumearc also removed sO that the system boots with no dependency on VxVM.

For vxunroot to work properly. all but one plcx or r ootvo L, swapvol. usr,va r, opt. and home must be removed (using vxedi tor vxplex).

II'this condition is not met. the vxunroot operation fails, and volumes arc notconverted back to disk partitions.

When 10 UsevxunrootUse vxunroot when you need to:

1300t from physical system partitions.

Change the size or location ofthe private region on the boot disk.


The vxunroot Command: Solaris

1. Ensure that the boot disk volumes only have oneplex each:vxprint -ht rootvol swapvol usr var

2. If boot disk volumes have more than one plex each,remove the unnecessary plexes:vxassist -g bootdg remove mirror volume!rootdisk

3. Run the vxunroot utility:vxunroot

Unencapsulating the Boot Disk: Solaris

The vxunroot command changes the volume entries in /etc/vEstab to theunderlying disk partitions for the root vol. swapvol. u s r, and var volumes.The command also modifies / etc / system and prompts for a reboot so that diskpartitions are mounted instead of volumes for the root, swap,usr. and varvolumes.

Creating a LVM Boot Disk from a VxVM Boot Disk: HP-UX

After booting to single user mode using a VxVM boot disk. you can completelyremove the LVM boot disk ifdesircd:

/etc/vx/bin/vxdestroy Ivmroot -v cOtldO

If you choose to keep the LVM disk. ensure that you update it with any changes tothe system disk.

This example shows how to create an LVM root disk on the cOt IdO physical diskafter removing the existing LVM root disk configuration from that disk.

/etc/vx/bin/vxdestroy_lvmroot -v cOtldO/etc/vx/bin/vxres_lvmroot -v cOtldO

If you want to take the boot disk completely out ofVxVM control. you then needto boot from the LVM root disk and use Volume Manager commands to removethe old boot disk from Vx VM control.


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3-23

svrnantec

Appendix 13provides complete lab instructions and solutions, "1,:1113 S"lu!ioIlS:

1'_l1C;lp"uLi1i~;n ~I!id l·~\Hl!;lhd!l~.. " !~;I.:::C I)

Lesson Summary

• Key PointsThis lesson described the disk encapsulationprocess and how to encapsulate the boot disk onyour system. Methods for creating an alternateboot disk and unencapsulating a boot disk werecovered.

• Reference Materials- VERITAS Volume Manager Administrator's Guide- VERITAS Storage Foundation Installation Guide

syrnantec

3-24

Lab 3

Lab 3: Encapsulation and RootabilityIn this practice, you create a boot disk mirror,disable the boot disk, and boot up from the mirror.Then you boot up again from the boot disk, breakthe mirror, and remove the boot disk from theboot disk group.Finally, you reencapsulate the boot disk and re-create the mirror.

'-;::L'F~Lab Exercises, see Appendix A.For Lab Solutions, see Appendix B.

Labs and solutions for this lesson arc located Oil the following pages:

Appendix A provides complete lab instructions. "Lib .l: l.ucap-ul.uion "!Iii

!\l,,{)uhlil~,"rJ;t~.~i..~.:\- ..:5

';op),n4"[ I. 2006 Sylll:mtec CurporH(IUI1 All "gilts -eservec


Lesson 4

Troubleshooting the Boot Process

Lesson Introduction• Lesson 1: Maintaining Data


the VxVM Architecture• Lesson 3: Encapsulation and

Rootability

• Lesson 4: Troubleshooting the Boot .'Process ,


Overview

syrnantec



Topic 1: Operating System Describe how VxVM integrates intoBoot Processes operating system boot processes.Topic 2: Troubleshooting Troubleshoot the boot process.the Boot ProcessTopic 3: Recovering the Recover the boot disk group forBoot Disk Group different boot disk failure scenarios.


symantec

OS Boot Processes

• Boot processes and VxVM startup scripts vary byplatform.

• Select the button at the bottom of the screen toreview the particulars for each platform.

SOlarlsl HP·UX I AlX I Linux.1

Operating System Boot ProcessesThe VxVM startup scripts and the way in which they integrate with the operatingsystem vary by platform. These processes are outlined in the "Boot Processes andVxVM Startup Scripts" appendix. For this portion of the training. tum to theappropriate portion of this appendix to follow along with the instructor.

4-3Lesson 4 Troubleshooting the Boot Process

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syrnantec

Files Used in the Boot Process

• jete/system (50Iari5). /stand/system (HP-UX)./ete/sysetl.eonf (Linux)Contains VxVM entries

• /ete/vfstab (50Iari5). /ete/fstab (HP-UXand Linux)Maps mount points to devices

• /ete/vx/volbootContains disk ownership data

• /ete/vx/lieenses/lie. /ete/vx/elmContains license fites

• /var/vxvm/tempdb (50Iari5). /ete/vx/tempdb (HP-UX)Stores data about disk groups

• /ete/vx/reeonfig.d/state.d/install-dbIndicates that VxVM is not initialized

• /VXVMII. II. II-UPGRADE/. start_runed (501ari5)Indicates that the VxVM upgrade is not complete

Troubleshooting the Boot Process

Files Used in the Boot Process

During the boot process, the VxVM startup scripts use information contained inspecific files. If any of these liles are missing. misplaced. or misconfigurcd, thenproblems can occur. Troubleshooting the boot process depends on these files:

/ete/system (Solaris only), /stand/system (HP-UX),/ ete/ sysetl. eonf (Linux)

On Solaris. contains VxVM entries indicating if the root disk has beenencapsulated. On all platforms, may contain Storage Foundatiun information,such as kernel module entries and tunable parameters

/ete/vfstab (Solarls), /ete/fstab (HP-IJX and Linux)

Maps Ii lc system mount points to actual device names

/ete/vx/volboot

Contains the host ID that was on the system when you ran vxinstall

/ete/vx/lieenses/lie./ete/vx/elm

Contains the files that represent installed VtRITAS license kcys

/var/vxvm/tempdb, (Solaris), /ete/vx/tempdb (lfP-IJX)

Stores temporary information about currently imported disk groups• /ete/vx/reeonfig.d/state.d/install-db

Indicates that VxVM packages have been added. but vxinstall has not run

• /VXVM#.#.#-UPGRADE/.start runedIndicates that a VxVM upgrade has been started but not completed

4-4 VERITAS Storage Foundation 5.0 for UNIX: MaintenanceCopyright 20Ot. Symantec COfIJO'<JI.on AII"QhIS reserved

Problem: Boot device cannot be opened.

symantec.

Troubleshooting: The Boot Device Cannot Be Opened

Possible causes:o Boot disk is not powered on.o Boot disk has failed.

SCSI bus is not terminated.o Controller failure has occurred.o Disk is failing and locking the bus.

To resolve:o Check SCSI bus connections.

- On Solaris. use probe-scsi-alL- On Linux use non- fast or verbose boot in the BIOS.- On HP-UX. use sea from the main menu.

o Boot from an alternate boot disk.

Troubleshooting: The Boot Device Cannot Be Opened

If the boot device cannot be opened. the system is unable to read the boot programfrom the boot disk. C0l11111oncauses for this problem include:

The boot disk is not powered on or has failed.

The SCSI bus is not terminated.

There is a controller failure.

A disk is failing and locking the bus. preventing any disks from identifyingthemselves to the controller. and making the controller assume that there are nodisks attached.

To troubleshoot the problem:

Check carefully that everything on the SCSI bus is properly connected.

I f disks are powered off or the SCSI bus is untcrminated, correct theproblem and reboot the system.

If one of the disks has failed, remove the disk from the SCSI bus andreplace it.

If no hardware problems are found, the error is probably due to data errors onthe boot disk. Attempt to boot from an alternate boot disk that contains a mirrorof the root volume.

If you arc unable to boot from an alternate boot disk. then you may still have sometype of hardware problem. Similarly, itswitching the tailed boot disk with analternate boot disk does not allow the system to boot. this condition also indicateshardware problems.


Copyngnl «J 2()06 Symantec Corporauon fill ncnts reserved

Troubleshooting: Startup Scripts ExitProblem: VxVMstartup scripts exitwithout initialization.Possible causes:Either of the following files are present:

• /etc/vx/reconfig.d/state.d/install-db

This file indicates that VxVM software packages have beenadded, but VxVM has not been initialized with vxinstall.Therefore, vxconfigd is not started.

• jvXVM#. #. # - UPGRADE/. start _runed (Solarts]This file indicates that a VxVM upgrade has been startedbut not completed. Therefore, vxconf igd is not started.

Troubleshooting: VxVM Startup Scripts Exit Without Initialization

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In the boot process. the YxYM startup scripts exits without initializing YxYM ifeither of the following flag files arc present:

• /etc/vx/reconfig.d/state.d/install-dbThe presence of this file indicates that YxYM software packages have beenadded. but YxVM has not been initialized with vxinstall. This file isinstalled when you add the YxYM software packages and is removed by thevxvm-reconfig script alter the configuration specified by vxinstall hasbeen performed.

The existence of this file communicates to the YxYM device drivers thatYxYM has not yet been initialized (vxinstall) and vxconf igd will notbe started. Therefore, if this file is present on the system. then the YxYMstartup scripts exit without pcrlonuing any initialization.

/VXVM#.#. #-UPGRADE/.start runed (Solaris)The presence ofthis [ilc indicates that a YxYM upgrade has been started butnot completed.

This file is created by the upgrade_start script specific to a particularVxYM version (for example, /VXVM3.5 - UPGRADE/ . start_runed) and isremoved by the upgrade_f ini sh script when an upgrade is completed.

If a file with this path is present. then the YxYM startup scripts exit withoutperforming any iuitialization, and vxconf igd is not started.

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Troubleshooting: Conflicting Host 10in volboot

Problem: A conflicting host 10 exists inthe /etc/vx/volboot file.

The volboot file contains the host IDthat was on thesystem when you installed VxVM.

If you manually edit this file. VxVM does not function.

• To change the host name in the vol boot file:vxdctl hostid net,'hostname

• To re-create the volboot file:vxdctl init (hostname1

Troubleshooting: Conflicting Host 10 in the volboot File

The /etc/vx/volboot tile contains the host 10 that was on the system whenyou first ran vxinstall. The host 10 in the volboot file is matched against thehost lD contained in the disk group header stored on every disk to identity thedisks belonging to this host.

Caution: Never attempt to manually edit the volboot tile. If you attempt tomanually edit the file. YxYM cannot function. The volboot file must be aspcci fie size (512 bytes on Solaris, 1024 bytes on II P-UX). If the tile is edited, forexample, by using the vi editor. and is not the correct size, the system will not boot.

To modify the vol boot file, you use the vxdctl command.To change the host name in the vol boot tile:vxdctl hostid newhostnameThis command places the new hust name (Y,YM host 10) in vol boot. Thenew host name is then flushed to the private region ofthe disks.To re-create the volboot tile:vxdctl init [hostname]If you must re-create this file, use the same host name (YxVM host 10) that theprevious vol boot tile contained.

Lesson 4 Troubleshooting the Boot Process

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Troubleshooting: License ProblemsProblem: License keys are corrupted, missing, or expired.

Save /etc/vx/licenses/lic/* to a backup device.

If the license files are removed or corrupted, you can copy thefiles back.License problems can occur if:• The /etc/vx/licenses/lic files become corrupted.• An evaluation license was installed and not updated to a full

license.

To resolve license issues:• vxlicinst• vxiod set 16• vxconfigd

Installs a new licenseStarts the I/OdaemonsStarts the configurationdaemon

Troubleshooting: Corrupted, Missing, or Expired License Keys

The /etc/vx/licenses/lic and /etc/vx/elmdircctorics contain the filesrepresenting the installed VERITAS license keys. You can encounter licenseproblems itthese files become corrupted or if~1I1evaluation license was installedand not updated to a full license.

During the boot process. if the system encounters a missing or invalid license key.YOli rccci vc error messages.

Replacing an Expired License

To replace an expired license. you can enter a new license by using the command:

vxlicinst

You must inform the configuration daemon (or reboot):

vxdctl enable


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Troubleshooting: Missing /tempdb

Problem: The /var/vxvm/tempdb (Solaris), /etc/vx/tempdb(HP-UX) directory is missing, misnamed, or corrupted.

This directory stores configuration information aboutimported disk groups.

The contents are re-created after a reboot.

If this directory is missing, misnamed, or corrupted,vxconf igd does not start.

To remove and re-create this directory:vxconfigd -k -x c1eartempdir

Troubleshooting: Missing or Misnamed /var/vxvm/tempdb

The /var /vxvm/tempdb directory is used to store configuration informationabout currently imported disk groups. The contents of this directory are re-createdafter a reboot. If this directory is missing. misnamed, or corrupted (due to disk 1/0failure), then vxconf igd does not start, and you receive an error message thatstates:

Cannot recover temp database

To remove and re-create the /var /vxvm/tempdb directory. you can use thecommand:

vxconfigd -k -x cleartempdir

Caution: You should kill any running operational commands (vxvol. vxsd. orvxmend) before using the -x cleartempdir option. You can use this optionwhile running VEA. or while VxVM background daemons are running(vxsparecheck. vxnot ify. or vxrelocd).

Note: Ifthe /var /vxvm (Solaris) or / et c /vx (II P-LJX) directory docs not exist,this command does not correct the problem.

For more information, see the vxconf igd (1m) manual page.

Lesson 4 Troubleshooting the Boot Process 4-9Cop,Tignt ?' 2006 Svmamec Corporation. All 'Igllts rsservso

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Troubleshooting: Debugging with vxconfigd

Running vxconfigd in debug mode:

vxconfigd -k -m enable -x debug_level• debug-tevet = 0 No debugging (default)• debug-tevet = 9 Highest debug tevet

Some debugging options:

• -x log Log all console output to the/var/vxvm/vxconfigd.log file.Use the specified tog fite instead.

Direct all consote output throughthe syslog (I interface.

Attach a date and time-of-daytimestamp to all messages.Log all possible tracinginformation in the given file.

-x logfile=name

• -x syslog

timestamp

-x tracefile=name

Troubleshooting: Debugging with vxconfigd

The vxconfigd Daemon

The V.xVM vxconf igd configuration daemon maintains disk configurations anddisk groups and is also responsible for initializing VxVM when the system isbooted. VxVM docs not start anything ilvxconf igd cannot be started during aboot-up. Under normal circumstances, this daemon is automatically started by theVxVM start-up scripts. However, if there is a problem. it may not be possible tostart vxconf igd. or the daemon may be running in disabled mode.

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Problem: The fete/system file isinvalid or missing.The fete/system file is used in the kernel initialization

and / sbin/ ini t phases of the boot process.

This file is a standard Solaris system file to which VxVMadds entries to:• Specify drivers to be loaded .• Specify root encapsulation.

If the file or these entries are missing. youencounter problems in the boot process.

Always maintain backup copies of this file.

.iL.:Troubleshooting: Invalid or Missingjete/system File (Solaris Only)

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Troubleshooting: Invalid or Missing fete/system File (Solaris Only)

The fete/system file is used in the kernel initialization phase as well as ill the/sbin/ init phase of the boot process. If this tile is missing. or if its entries aremissing. then you encounter problems at boot time.

The jete/system file is a standard Solaris system file. VxVM adds entries tothis file that are placed between the tags:

*vxvm START (do not remove)

*vxvm END (do not remove)

It is strongly recommended that youmaintain a backup copy of the /ete/system file so that you can recover your root volume if the system becomesunbootable. !fthe system cannot read the jete/system file. then you can use theboot -a command to specify a different copy of the jete/system tile to use onbooting.

VxVM entries in / ete/ system that begin with foreeload: specify drivers tobe loaded by V-xVM. For example:

foreeload: drv/peiforeeload: drv/dadforeeload: drv/vxdmpforeeload: drv/vxioforeeload: drv/vxspee


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Troubleshooting: Invalid or Missing / etc / sys tern File(Solaris Only)-----------,--ok> boot -a

When booting from an alternate system file, donot go past the maintenance mode. Boot up onthe alternate system file, fix the VxVM problem,and then reboot with the original system file.Re s e t t f nq

Reboot i nq w i t h command: boot aBoot device: /pcLlf,O/pCl.d,1I1ded/disk',Q,Q File and args:Enter filename {kernel/unix]: (Press Return.)Enter default directory for modules l!platform!SUNW,Ultra·S lO/kernel

Iplatform!sun4u/kernel Ikernel /usr/kernel): (Presl Return.)SunOS ReLease 5 6 ve i-s i on Generic_lOSI81-03[UNIX(RI Sys t em V Release 4 1]

Copyri qht 1983-19')7, Sun ni croeys t ems. Inc.Nameof system file (ete/system1: etclsystem.preencaproot filesystem type [uEsl: (Press Return.)Enter physical name of root device

[/pci@lf, O/pci@l, 1/ide@3/disk@O, 0: al: (Press Return.)VxVI') st ert ing ill boot mode.;

Ty-pe Ct rl vd to proceed with not-mal startup,(01' q i ve root passv.c.rd for syst.em mei nt enance.r:Ent er i nq System t+a intenence node

Using an Alternate sys tern Hle (SlIlaris only)

When using an alternate system file. you will probably not be able to boot intomultiuser mode and will end in maintenance: mode.

Note: Do not go past the maintenance mode while booting on this system file.1300t lip on the alternate system file. fix the VxVM problem, and then rebootwith the original system file.

The system boots on the partition. not on the volume. When you enter into themaintenance mode. you will notice that the volume rootvol is not started.

Aller you arc: finished, unmount /mnt and reboot the system under the normalsystem IIIe.

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Using Interactive Mode (Linux only)

• On Linux, you can boot into Interactive modeby pressing i after the boot loader windowdisplays.

• You are then prompted for additionalinformation.

Using Interactive Mode (Linux only)

On Linux, you can boot into Interactive mode by pressing i after the boot loaderwindow displays.

You are then be prompted for information similar to the Solaris boot - acommand.

Lesson 4 Troubleshooting the Boot Process 4-13

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Recovering the VxVM Boot Disk (HP-UX Only)

Stop the failed boot process using ctlr-b.

Reset the system <r s>,

Press any key within 10 seconds when you receive the message:"To discontinue. resa an ke within 10 seconds."

Boot from a specified path cbo pri>.

Enter y to interact with tPL.

Enter bpux -vm to access the Maintenance Mode Boot (MMB).

Start VxVM manual! usin the vx emerg start command.

Use CBR or various VxVM commands to complete the recovery.

Recovering the YxV:\1 Bool Disk (lIl'-LJX only)

011HP-UX. you call recover the VxVM boot disk by following the steps displayedon the slide.

4-14Cor-vnqnt ~ 2006 Svmaritec Corooranon All nqtus reserved


Temporarily Importing the Boot Disk Group

Through a temporary import, you can bring the boot diskgroup to a working system and repair it there:

1. Obtain the disk group 10 of the boot disk group:vxdisk -s list

diskid:954254545.2009.train06dgname: sysdgdgid: 952435045.1025.train06hostid:train06

2. On the importing host, import and temporarily rename the diskgroup:vxdg -tC -n tmpdg import 952435045.1025.train06

3. Fix and replace the files and volumes as necessary.4. Deport the disk group back to the original host:

vxdg -h train06 deport tmpdg

Recovering the Boot Disk Group

Temporarily Importing the Boot Disk Group

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By temporarily importing the boot disk group. you can bring the boot disk groupfrom a failed system to a working system and repair it there. Use this method whenyou have an encapsulated boot disk and do not have a backup system file andemergency boot disk.

To temporarily import the boot disk group:

1 Find the disk group lD of the boot disk group.

2 On the importing host, import and temporarily rename the disk group.

3 Repair files and volumes as needed.

4 Deport the disk group back to the original host.

~ut(': This is useful if you can boot 011'an array.

Repairing the Failed Root

By temporarily importing the boot disk group on another host. you can repair thefailed root. Mount the volume and replace tiles as needed:

vxrecover -g tmpdg -s rootvol

mount /dev/vx/dsk/tmpdg/rootvol /mnt


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Boot Disk Failure Scenarios

o In the next slides, several disk failure scenarios arepresented that involve the boot disk or disks in theboot disk group.

o For each of the following failure scenarios,determine the impact of the failure and a recoverystrategy.

Boot Disk Group Failure and Recovery Scenarios

The recommended practice for managing your boot disk is to place the boot disktinder YxYM control and mirror the boot disk. However. if you place the boot diskunder YxYM control and do not mirror the boot disk. then you must develop anunderstanding of the impact of disk failure involving the boot disk or other disks inthe boot disk group. and the associated recovery strategies.

In this section. several disk failure scenarios arc presented that involve the bootdisk or disks in the boot disk gruup. For each of the following failure scenarios.determine the impact of the failure and a recovery strategy. Base your answers onyour understanding of recovery procedures. the boot process, and the filesassociated with booting the operating system and YxYM.

Solutions for each recovery scenario are presented at the end of this section.

4-16Cupyrlgnt~, 2006 Symantec COfpor"IIOIl All notus reserved

VERITAS Storage Foundation 5.0 for UNIK Maintenance

Scenario 1datadg

Because the hoot disk is encapsulated and mirrored. there is no negative impactand nothing is lost. The only recovery necessary is to replace the failed disk, aswith any other failed disk.

www~~~

What is the impact ofthe failure?What systeminformation or softwareis lost?

• What is your recoverystrategy?

The boot disk is underVxVM control, plusmirrored, and fails.

B = Boot diskD = Data diskV = Volume

Scenario I: Boot Disk Failure (Encapsulated)

In this scenario:

The boot disk is under VxVM control and mirrored.

The boot disk fails.


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Scenario 2datadg

The boot disk is notunder VxVM controland fails.

wwwlmrnJrnJ• What is the impact of

the failure?What systeminformation or softwareis lost?What is your recoverystrategy?

B = Boot diskD = Data diskI V = Volume

Scenario 2: Boot Disk Failure (:'IIot encapsulated)

In this scenario:

The boot disk is not under VxVl'vl control.

The boot disk lails.

Answer the following questions:

What is the immediate impact of the I~i lure?

On the system?

On disk groups?

On vxconf Lqd?

What software or configurution data has been lost or is inaccessible?Disk group configurations?Data·)

What is your recovery strategy"

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Scenario 3datadg

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sysdg

WW

The boot disk is underVxVM control, but notmirrored, and fails. Noother disks exist in theboot disk group.

What is the impact ofthe failure?What systeminformation or softwareis lost?What is your recoverystrategy?B = Boot disk

D = Data diskV = Volume

Scenario 3: Boot Disk Failure with Onlv One Disk in the Boot Disk Group

In this scenario:

The boot disk is tinder YxYM control. but not mirrored,

The boot disk fails,

The boot disk is the only disk in the boot disk group,

Answer the following questions:

What is the immediate impact of the failure?On the system')

On disk groups'?

On vxc on f iqd"

What software or configuration claw has been lost or is inaccessible'?

Disk group configurations'?Data')

What is your recovery strategy'?

4-19Lesson 4 Troubleshooting the Boot ProcessCopyrog~)lC: 2006 Syeuantec Corporanon. All fight!'. reserved

Scenario 4

datadg

mWLYJ@j@jtQj

VxVM control, but notmirrored, and fails. Otherdisks exist in the bootdisk group.

• What is the impact ofthe failure?What systeminformation or softwareis lost?What is your recoverystrategy?

B = Boot diskD = Data diskV = Volume

Scenario 4: Boot Disk Failure with Other Disks in the Boot Disk Group

In this scenario:The bout disk is under VxVM control. but not mirrored.The boot disk fails.Other disks exist in the boot disk group.

Answer the Iollowing questions:What is the immediate impact of the failure'

On the system"On disk groups"On vxconfigd'.'

What software or configuration data has been lost or is inaccessible'!Disk group configurations')Data'!

What is your recovery strategy"

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Scenario 2: Impact of the Failure

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The boot disk is not under VxVM control and fails.

What is the immediate impact of the failure?

On the system? System disk has failed.

On the disk groups? Disk groups are not available.

On the vxconfigd? vxconf igd is not accessible.

What software and configuration data has been lost?

Disk group configurations?Still stored in private regions on disks within each disk group

Data?Data in all disk groups is still present, but it must be checkedfor integrity before use.


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Scenario 3: Impact of FailureThe boot disk is under VxVM control, but not mirrored,and fails. No other disks exist in the boot disk group.


On the system? The system fails when 1/0On the disk groups? to a boot disk volume isOn the vxconf igd? attempted.

What software and configuration data has been lost?Disk group configurations?Bool disk group configuration is lost. Other disk groupconfigurations are still stored in private regions on diskswithin each disk group.

Data?Data stored on the boot disk is lost. Data in other disk groupsremains on the disk and is accessible after volumes can bestarted. The data requires integrity checking.


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Scenario Recovery Strategy (This recovery strategy applies to scenarios Z,3, and 4.)

With a boot disk that is under VxVM control and mirrored. you can replace the failed diskusing standard disk replacement procedures. When the boot disk is not under V xVMcontrol. or not mirrored. and fails, your recovery strategy involves the following:

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Scenario 4: Impact of Failure

The boot disk is under VxVM control, but not mirrored,and fails. Other disks exist in the boot disk group.


On the system?On the disk groups?On the vxconfigd?

The system fails when 1i0to a boot disk volume isattempted.

What software and configuration data has been lost?Disk group configurations?Boot disk group configuration is stili stored in private regionsof other disks in the boot disk group. Other disk groupconfigurations are still stored in private regions on diskswithin each disk group.Data?Data stored on the boot disk is lost. Data on other volumeswithin the boot disk group. or any other imported disk groups.remains intact. The data requires integrity checking.

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4-22 VERITAS Storage Foundation 5.0 for UNIX- Maintenance

Scenario 4: Recovery StrategyThis recovery strategy applies

1. Physically replace the failed disk. to scenarios 2, 3, and 4.2. Reinstall the OS using the same host name as before the failure.3. Reinstall Storage Foundation using the installation scripts.4, Run vxd Lak list. to see if your disks are up and running.

The disk groups are imported automatically after vxcon t Lqd is started.If you did not reboot your system after the reinstallation. you must executevxr ecov ex - s to start the volumes in any data disk groups.

5. Clean up the configuration:• MOllnt file systems that should be mounted. (To mount VxFS file systems,

you must have rebooted the system after reinstalling Storage Foundation.)• Restore application binaries and config files that reside on the boot disk.• Reboot the system if necessary.

6. If the boot disk was under VxVM control, reconfigure rootability (forScenarios 3 and 4):• Remove old volume records for root volumes.• Remove the old disk media record for the boot disk.• Put the boot disk under VxVM control and mirror the boot disk.

Copvnqht 2006 Svmantec Co-porauon /'III "ghls reserved

Creating an Emergency Boot Disk (Solaris Only): Self Study

Why Create an Emergency Boot Disk?

Encapsulating and mirroring the boot disk ensures that if your boot disk is lost, thesystem continues to operate on the mirror disk. You can provide further protectionfor your system by creating an emergency boot disk that contains the operatingsystem and VxVM software.

You can use an emergency boot disk:

To repair encapsulated boot failure

When there is no backup system file

When UNIX does not boot

An emergency boot disk boots up on a Volume Manager-knowledgeable disk.

"IlIte: YOII cannot boot from SAN disks unless you have a special boot prom fromSun supporting the SAN device.

Solaris: Emergency Boot Disk Creation

To create an emergency hoot disk:

Format a disk, place a mot partition and a swap partition on the disk, and labelthe disk. Make the root partition large enough to hold us r, va r, and opt.

2 Create a file system:

newfs /dev/rdsk/eOtldOsO3 Mount and copy files to the new boot disk:

mount -F ufs /dev/dsk/eOtldOsO /mntfind / /usr /var /opt -local -mount -print I epio \-pmudv /mntThe find utility recursively searches the given directory paths and prints (tothe standard output) the path names of all the files that arc local to that filesystem.

The cpio -p command reads the standard input to obtain a list of path namesof tiles that are then created and copied into the destination directory tree,which is the /mnt mount point.

4 Place a boot block on the disk:

/usr/sbin/installboot /usr/platform/-uname \-i-/lib/fs/ufs/bootblk /dev/rdsk/eOtldOsOThe installboot command installs the specified platform-dependent bootblocks to the given disk partition.

S Edit the /mnt/etc/system file to comment out the non-forceload linesrelated to VxVM.

6 Edit the /mnt/etc/vfstab file to remove references to the root volumes(rootvol. /usr, /var, /opt, and so on), and place an entry for theemergency boot device as the root device.

7 Create the /mnt /tmp, /mnt /proc. and /mnt /mnt directories:


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mkdir /mnt/tmp /mnt/proc /mnt/mnt8 Unmount /mnt:

umount /mnt9 Write down the Solaris device name for the emergency boot disk. For example:

ls -1 /dev/dsk/cOtldOsO/deviees/pei.lf,O/peiil/sesi~3/sd~e,O:aFor booting. you need the device name:

/peiilf,O/pei~1/sesia3/diskle,O:a10 Run the following command:

init 011 Boot from the emergency boot disk. For example:

boot /pci@lf,O/pci@1/scsi@3/disk@e,O:a

Solaris: Booting from an Emergency Boot Disk

After you have an emergency boot disk. you can boot YOllr system on the disk byusing the full Solari, device name. lhcn, you can mount the volume onto adirectory:

vxrecover -s rootvo1

mount -F ufs /dev/vx/dsk/bootdg/rootvo1 /mnt

You can now replace any missing files. I I'you have to run vxlieinst, copy thecreated files in the /ete/vx/lieenses/lie directory to the/mnt / ete/vx/l ieenses/ lie directory. When you arc finished. unmount thevolumes, and reboot the system on the regular boot disk.

Ifvxeonf igd has problems starting up. try starting VxVM manually by runningthe following commands:

vxiod set 10

vxconfigd

vxrecover -s

You can also specify debugging options to the vxeonEigd command to identifythe problem.

Linux: Creating Bootable CDs or Floppy DisksOn l.inux , the emergency boot disks arc booiablc CD-ROMs or floppy disks. Forexample. i I' you have CD I of Red Hat. YOll call bout and select Rescue mode andthen you can mount root.

You can create a boot lloppy disk. hut it is not a rescue floppy disk. It is simplyanother way to load the initrd and kernel. The boot Iloppy disk loads and thenmounts root.

VERITAS Storage Foundation 5.0 for UNIX. Maintenance4--24

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Lesson Summary

• Key PointsThis lesson described how VERITAS Volume Managerintegrates into the operating system boot processes,the key scripts and files used in the boot process, andtips on troubleshooting the boot process. This lessonalso provided procedures for recovering from variousboot disk failures.

• Reference Materials- VERITAS Volume Manager Administrator's Guide- VERITAS Volume Manager Troubleshooting Guide

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Appendix A provides complete lab instructions. "I "hi: Irllllbksll,,(lril\l~ the' B,")1Procc-.s." p::lgc f\··_~5

Lab 4

Lab 4: Troubleshooting the Boot ProcessIn this lab, you practice recovering fromencapsulated boot disk failure scenarios.On the Solaris platform, to investigate andpractice recovery techniques, you will use a set ofinteractive lab scripts. Each script simulates afailure in the encapsulated boot disk (and itsmirror, if required) and reboots the system.

For Lab Exercises. see Appendix A,For Lab Solutions. see Appendix B.

Appendix 13provides complete lab instructions and solutions. "lnl: of SOllli,,'!]S:

I'rollhk,h,)(lling the Hout I'II)(C" .." l':l~L'H-~!


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Lesson 5

Volume Maintenance

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Lesson Introduction" Lesson 1: Maintaining Data

Consistency" Lesson 2: Managing Devices Within

the VxVM Architecture" Lesson 3: Encapsulation and

Rootability" Lesson 4: Troubleshooting the Boot

Process_"_!:esson 5: Vo/urn! Ma!!!~n~nce. _" Lesson 6: Performance Monitoring" Lesson 7: Point-in-Time Copies" Lesson 8: Other Enterprise Features

Overview

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Topic 1: Changing the Change the volume layout while the~~ume Layout volume remains online.Topic 2: Managing Volume Manage volume maintenance tasksTasks with VEA and from the command line.Topic 3: Analyzing Analyze volume configurations byVolume Configurations using the Storage Expert utility.with Storage Expert

5-2C"pynyllt, 2006SvmautecCorpnranonAll foyllis reserved


1,.1JiIIi::----~~1--'::;l"iI£2Jlt-----Changing the Volume Layout

Online relayout: Change the volume layout orlayout characteristics while the volume is online.

volume

Examples:• Change concatenated to mirror-concat to achieve redundancy.

• Relayout RAID-5 to mirrored for better write performance.Relayout mirrored to RAID-5 to save space.

• Change stripe unit size or add columns to achieve desiredperformance.

Convert a mirror-concat to a stripe-mirror to increase redundancyand performance while decreasing the recovery time.

Changing the Volume Layout

What Is Online Relayout?

You may need to change the volume layout in order to change the redundancy orperformance characteristics of an existing volume.

The online rclayout feature ofVxVM enables you to change from one volumelayout to another by invoking a single command. You can also modify theperformance characteristics of a particular layout to reflect changes in yourapplication environment. While iclayour is in progress, data on the volume can beaccessed without interruption.

Online relayout eliminates the need tor creating a new volume in order to obtain adifferent volume layout. Relayout allows you to modify an existing volume into allthose layouts you can select when creating a volume.

Supported Transformations

By using online rclayout, you can change the layout of an entire volume or aspecific plex. Use online relayout to change the volume or plex layout to or from:

ConcatenatedStripedRAID-.'Striped mirroredConcatenated mirrored

Lesson 5 Volume Maintenance

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The transformation of data from one layout to another involves rearranging thedata in the existing layout into the new layout. Data is removed from the sourcesubvolumc in portions and copied into a temporary subvolumc, or scratch pcu].The temporary storage space is taken from the free space in the disk group. Dataredundancy is maintained by mirroring any temporary space used.

The area in the source subvolumc is then transformed to thc new layout, and datasaved 111 the temporary subvolumc is written back to the new layout. Thisoperation is repeated until all the storage and data in thc source subvolumc arctransformed to the new layout. Read/write access to data is not interrupted duringthe transformation.

How Does Relayout Work?

Data is copied one chunk ata time to a temporary area.

TemporarySubvolume(scratch pad)

l lull of the plexes in the volume have identical layouts. VxVM changes all plcxesto the new layout. If the volume contains plcxcs with different layouts. you mustspecify a target plcx. VxVM changes the layout of the target plcx and docs notchange the other plcxcs in the volume,

File systems mounted on the volumes do not need to be unmounted to performonline rclayout, as long as online rcsizing operations can be performed on the lilesystem.

If the system i~lils during a transformation, data is not corrupted. Thetranstormauon continues alter the system is restored and read/write access ismaintained.

I Data is returned from the temporary-----'....:.J...---" area to a new tayout area.

By default:• tf votume size is tess than 50 MB, the temp area = votume size.• If the votume size if greater than 50MB, temp area is 10% of the votume

size with a minimum value of 50MB and a maximum value of 1GB.Note: Additional temporary or permanent space may be required forcertain relayout changes, for example if the number of columns of astriped volume is modilied.

How Does Online Relayout Work?

5-4 VERITAS Storage Foundation 5.0 for UNIX: Mall1tenance

Temporary StorageSpace

YxYM determines the size of the temporary storage area. or you can specify a sizethrough YEA or vxassist. Default sizes arc as follows:

If volume size is less than 50 M13. the size of the temporary area is equal to thesize of the volume.Ifthe volume size is larger than 50 MB. the temporary area is 10 percent of thevolume size with a minimum value of SOMB and a maximum value of I CiB.

Specifying a larger temporary space size speeds up the layout change process.because larger pieces of data are copied at one time. If the specified temporaryspace size is too small. YxYM uses a larger size.

:\ote: There may be other temporary spare requirements depending on the change.for example. while increasing the column length of a striped volume.

Lesson 5 Volume Maintenance 5-5

Online Relayout Notes

• You can reverse online relayout at any time.• Some layout transformations can cause a slight

increase or decrease in the volume length due tosubdisk alignment policies. If volume lengthincreases during relayout, VxVM resizes the filesystem using vxresize.

• Relayout does not change log plexes.

• You cannot:- Create a snapshot during relayout.- Change the number of mirrors during relayout.- Perform multiple relayouts at the same time.- Perform relayout on a volume with a sparse plex.

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Notes on Online RelayoutReversing online relayuut: You can reverse the online rclayout process at anytime, but the data may not be returned to the exact previous storage location.Stop existing transformauon in the volume before pcrfurming a reversal.

Volume length: Some layout transformations can cause a slight increase ordecrease in the volume length due to subdisk alignment policies. If the volumelength changes during online rclayout, V.xVM uses vxresize to shrink orgrow a IiI.: system mounted on the volume.

Log plexes: When you change the layout of a volume. the log plcxcs arc notchanged. Bellm; you change the layout of a mirrored volume with a log, thelog plcxcs should be removed and then re-created alter the rclayout.

Volume snapshots: You cannot create a snapshot ola volume when there is anonline rclayout operation running on the volume.

"lumber of mirrors: During a transformation. you cannot change the numberor mirrors in a volume.

"u/tipl!' relayouts: A volume cannot undergo multiple rclayouis at the sametime.Sparse plexes: Online rclayout cannot be used to change the layout of avolume with a sparse plcx.

Suhdisks: After a rclayout. subdisks may need to be 1110\ cd andjoined.

5-6Copyright' 20()6 SvruamecCorporauou All flyills -e se-vec


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Changing the Layout: VEA

volume natl\~:Id",t,3\.oIOI

layoul:

r. Ccoceceneted

r Striped

r RAI~5

r 5tripedMirrorl!'d

I r Ret"", .'oIumesizelit completion

l Temp space SIZI!: I ~

ID1sks:1

Temp<I>k(s):Ii------------

I rercet plex:,;--------------er=-o"-'-.,-,-j

Set relayout options,

Browse."

Btowse ..

Changing the Volume Layout: VEA

Select: The volume 10 be changed to a di tferent layout

Navigation path: Actions->Change Layout

Layout: Select the new volume layout and specify layout detailsas necessary.

Options:To retain the original volume size when the volume layoutchanges. mark the "Retain volume size at completion' check box,

To specify the size of the pieces of data that arc copied totemporary space during the volume relayout. type a size in the"Temp space size" field.

To specify additional disk space to be used for the new volumelayout (if needed). specify a disk in the Diskis) field or browse toselect a disk.

To specify the temporary disk space to be used during the volumelayout change. specify a disk ill the "Temp diskts)" field orbrowse to select a disk,

If the volume contains plcxcs with different layouts. specify theplex to be changed to the new layout in the "Target plex" field,

Input:

Lesson 5 Volume Maintenance 5-7

svmamec.

Changing the Layout: VEA

Relayout Status Monitor Window

st.tus StatusVolume nerne: d4t.volOl InformationIr.itloll.yout: CONCAT

Desaed levout: STRIPED-MIRROR, columns=2, stwidth=128stetus: Executin9 (Rel.youtl

% Complete: .•... - .. __ ._ - . 5%

C:p;;;Jiej!Abort I

. Relayoutcontrols

When you launch a rclayout operation. the Rclayout SWills Monitor window isdisplayed. This window provides intormatiou and options regarding the progressor the rclayout operation.

Volume Name: The name of the volume that is undergoing rclayout

I nitial Layout: The original layout or the volume

Desired Layout: The new layout (or the volume

Status: The status or the rclayout task

0;', Complete: The progress or the rclayout task

The Rclayout Status Monitor window also contains options that enable you tocontrol the rclayout process:

Pause: To temporarily stop the rclayout operation, click Pause.

Abort: To cancel the rclayout operation, click Abort.

Continue: To resume a paused or aborted operation. click Continue.

Reverse: To undo the layout changes and return (he volume to its originallayout. click Reverse.


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Changing the Layout: CLIvxassist relayout

Is used for non layered relayout operations

• Is used for changing layout characteristics, such as stripewidth and number of columns

vxassist convert

• Changes nonlayered volumes to layered volumes, andchanges layered volumes to non layered volumes

• Does not require data movement

Note: vxassist relayout cannot create a nonlayered mirroredvolume in a single step. The command always creates a layeredmirrored volume even if you specify a nonlayered mirroredlayout. Use vxassist convert to convert the resulting layeredvolume into a nonlayered volume.

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From the command line, online relayout is initiated using the vxassistcommand.

The vxassist relayout command is used for all non layeredtransformations, including changing the layout of a plex, stripe size. and/ornumber of columns.The vxassist convert command is used to change the resilience level ofavolume; that is. to convert a volume from nonlayered to layered. or fromlayered to nonlayered.Use this option only when layered volumes are involved in the transformation.

The vxassist relayout operation involves the copying of data at the disklevel in order to change the structure of the volume. The vxassist convertoperation does not copy data: it only changes the way the data is referred to.

Note: vxassist relayout cannot create a nonlayercd mirrnrt'dvolume in asingle step. The command always creates a layered mirrored volume even if youspecify a non-layered mirrored layout, such as mirror-stripe or mirror-concat. Usethe vxassist convert command to convert the resulting layered mirroredvolume into a nonlayered mirrored volume.

Changing the Volume Layout: CLI


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vxassist relayoutsyrnantec

vxassist -g diskgroup relayout vOlumelplexlayout=layout ncol=[+I-]ncol stripeunit=size

To change to a striped layout:vxassist -g datadg relayout datavol layout=stripe ncol=2

To add a column to striped volume datavol:vxassist -9 datadg relayout datavol ncol=+l

To remove a column from datavol:vxassist -9 datadg relayout datavol ncol=-l

To change stripe unit size and number of columns:vxassist -9 datadg relayout datavol stripeunit=32k ncol=5

To change mirrored layouts to RAID·5, specify the plex to be converted(instead of the volume):vxassist -g datactg relayout datavolOl-Ol layout=raidS \strlpeunit=32k ncol=)

The vxassist relayout CommandWhen changing to a striped layout. you should always specify the number ofcolumns. or the operation Illay Iail with the following error:

vxvm:vxassist: ERROR:Cannot allocate space for 51200 blockvolumevxvm:vxassist: ERROR:Relayout operation aborted.

Any layout can be changed to RAID·S itsuflicicnt disk space and disks exist in thedisk group. If the neol and stripeunit options arc 110tspecified, the defaultcharacteristics are used.

When using vxassist to change the layout ola volume to RAID·S, VxVM mayplace the RAID·S log on the same disk as a column, lor example. when there is noother free space available. To place the log on a different disk, you can remove thelog and then add the log to the location of your choice.

If you convert a mirrored volume to RAID·S. you must specify which plcx is to beconverted. All other plcxcs are removed when the conversion has finished.releasing their space lor other purposes. I l you convert a mirrored volume to alayout other than RAID·S. the unconverted plcxcs arc not removed.

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vxassist convert

Use vxassist convert to convert:• mirror-stripe to stripe-mirror

• stripe-mirror to mirror-stripe

• mirror-concat to concat-mirror

• concat-mirror to mirror-concat

To convert the striped mirrored volume datavol to alayered stripe-mirror layout:vxassist -g datadg convert datavol \layout=stripe-mirror

The vxassist convert Command

To change the resilience level ofa volume, that is, to convert a nonlayered volumeto a layered volume, or a layered volume to a nonlayered volume, you use thevxassist convert option. Available conversion operations include:

mirror-stripe 00 stripe-mirror

stripe-mirrorOOmirror-stripe

mirror-concattoconcat-mirror

concat-mirrorwmirror-concat

The syntax for vxassist convert is:

vxassist -g diskgroup convert volume name layout=layout

Lesson 5 Volume Maintenance 5-11Copynqnt f 2006 Svmanter. Corporation /1.11nants reserv&(j

Managing Volume Tasks: VEARelayout Status Monitor Window

Displays automatically when you start relayout• Enables you to view progress, pause, abort, continue, or reverse the

relayout task• Is also accessible from the Volume Properties window

Task History Window• Displays information about the current-session tasks

• Can be accessed by clicking the Tasks tab at the bottom of the mainwindow

Enables you to right-click a task to abort, pause, resume, or throttle atask in progress

Task Log• Contains a list of tasks performed in the current session• Can be accessed by clicking the Logs tab to the left of the main windowCommand Log File

Contains history of current- and previous-session tasks• Is located in /var / adm/vx/veacmdlog

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Managing Volume Tasks

Managing Volume Tasks: VEA

Relayout Status Monitur Winduw

Through the Rclayout Statu, Monitor window, you can view the progress of therclayoui task alld also pausc. abort. continue, or reverse the rclayout task. You canalso access the Rclayout Status Monitor through the Volume Properties window.

Task Hlstory ''''indow

The Task History window displays a list or tasks performed in the current sessionand includes the name ofthe operation performed, target object, host machine,start time. status. and progress. To display the Task History window, click theTasks tab at the bottom or the main window.

When you right-click a task in the list and select Properties, the Task Propertieswindow is displayed. In this window. you can view the underlying commandsexecuted to pcrtorm the task.

Command Log File

The command log file. located in /var / adm/vx/veacmdlog, contains ahistory or V 1-.A tasks performed in the current session and in previous sessions.The file contains task descriptions and properties. such as date, command. output,and exit code. All sessions since the initial VEA session arc recorded. The log rileis not sclt-Iimiting and should therefore be initializcd periodically to preventexcessive use of disk space.


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Managing Volume Tasks: ell

What is a task?• A task is an operation, such as online

relayout, that is in progress on the system.• Task ID is a unique number assigned to a single task.

• Task tag is a string assigned to a task or tasks bythe administrator to simplify task management. For mostutilities, you specify a task tag using:-t task_tag

Use the vxtask command to:

• Display task information.

• Pause, continue, and abort tasks.

• Modify the progress rate of a task.

Managing Volume Tasks: ell

To monitor and control volume maintenance operations from the command line,you use the vxtask and vxrelayout commands.

Task tag is a string assigned to a task or tasks by the administrator to simplify taskmanagement. For example.:

vxassist -g datadg -t CreateMirrorVo1umeTask datavo1109 1ayout=mirror


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vxtask list

To display information about tasks:vxtask [-ahlprJ list !task_idltask_tagJ

Starting, ending, andcurrent offset

type

, Affected, VxVM object

Displaying Task Information with vxtask

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To display information about tasks. such as rclayout or rcsynchronizationprocesses, you use the vxtask list command. Without any options. vxtasklist prints a one-line summary for each task running on the system. lnformauonin the output includes:

TASKID The task identifier assigned to the task by VxVM

The ID olthc parent task. ilany

I lthc task must be completed before a higher-level task iscompleted, the higher-level task is called the purenttusk .

TYPE/STATE The task type and state

PTID

The type is a description or the work being performed. suchas RELAYOUT. The statc is a single letter representing oneor three suucs:

-R: Running

-P: Paused

-A: Aborting

ThL' percentage or the operation that has been completedto this pointThc starting. ending. and current offset 1'01' the operation,separated by slashes. a description or thc task. and namesor objects that arc affected

peT

PROGRESS

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vxtask list OptionsTo display task information in long format:vxtask -1 list

To display a hierarchical listing of parent/child tasks:vxtask -h list

To limit output to paused tasks:vxtask -p list

To limit output to running tasks:vxtask -r list

To limit output to aborted tasks:vxtask -a list

To limit output to tasks with a specific task 10 or task tag:vxtask list convertopl c··············,! Task tag I

Options forvxtask list

Several options for vxtask 1 ist arc illustrated in the slide.


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symantec

vxtask monitorTo provide a continuously updated list of tasks runningon the system, use vxtask moni tor:

vxtask [-c count] [-In] [-t time]

[-w interval] monitor [task_idj task_tag]

-1: Displays task information in long format

-n: Displays information for tasks that are newly registered while theprogram is running-c count: Prints count sets of task information and then exits

• - t time: Exits program after time seconds

-w inr erveJ: Prints ..waiting ... " after interval seconds with noactivity

When a task is completed, the STATE is displayedas EXITED.

Monitoring a Task with vxtask

To provide a continuously updated listing oftasks running on the system. you usethe vxtask monitor command. (The vxtask list output represents a pointin time and is not continuously updaicd.) With vxtask monitor, you can trackthe progress Dr a task on an ongoing basis. By default. vxtask monitor prints aone-line summary for each task running on the system.

vxtask monitorTA5KID PTID TYPE/STATE

RELAYOUT/R

peT PROGRESS

58.~8% 0/20480111976 RELAYOUT datavol198

The output is the same as for vxtask 1 ist, but changes as information about thetask changes.

When a task is completed, the STATE is displayed as EXITED.


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Using pause, abort. and resume

For example, you can pause a task when the system is under heavy contentionbetween the sequential l/O of the synchronization process and the applicationstrying to access the volume. The pause option allows an indefinite al11011l1toftime for an application to complete before using the resumeoption to continuethe process.

The abort option is often used when reversing a process. For example, if youstart a process and then decide that you do not want to continue, you reverse theprocess. When the process returns to 0 percent, you use abort to stop the task.

Note: After you abort or pause a relayout task, you must at some point eitherresume or reverse it.

vxtask

To abort, pause, or resume a task:vxtask abort [pauseI resume task~id I t:ask~tag

To pause the task with the task 10198:vxtask pause 198

To resume the task with the task 10198:vxtask resume 198

To abort the task with the task tag convertop1:vxtask abort convertop1

Controlling Tasks with vxtask

You can abort. pause, or resume a task by using the vxtask command. Youspecify the task ID or task tag to identify the task.

Lesson 5 Votume Maintenance

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5~17

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Controlling Relayout Tasks with vxrelayout

The vxrelayout command can alsu be used to display the status otrclayoutoperations and to control rclayout tasks.

The s tat us option displays the status of an ongoing or discontinued layoutconversion.

vxrelayout

The vxrelayout command can also be used todisplay the status of, reverse, or start a relayoutoperation:vxrelayout -9 diskgroup statuslreverselstartvolume name

Note: You cannot stop a relayout with vxrelayout. Only thevxtask command can stop a relayout operation.

vxrelayout -g da~~s-t-a-t-u--s--d-a-t-a-V-Q-l-.-_~; Source layout I. ..L

58.48% completed. ~estination layout

Percentage of task Icompleted j·. .------i

The reverse option reverses a discontinued layout conversion. Before youuse this option. the rclayout operation must be stopped using vxtask abort.

The start option continues a discontinued layout conversion. Before you usethis option, the rclayout operation must have been stopped using vxtaskabort.

For example. to display information about the rclayout operation being performedon the datavol volume. which exists in the datadg disk group:

vxrelayout -g datadg status datavolSTRIPED, columns=5, stwidth=128 --> STRIPED, columns=6,stwidth=128

Relayout running, 58.48% completed.

The output displays the characteristics or both the source and destination layouts(including the layout type. number of columns. and stripe width). the status of theoperation. and the percentage completed.

In the example. the output indicates that an increase from live to six columns for astriped volume is more than halfway completed.


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Controlling Task ProgressTo control the 1/0 rate for mirror copy operationsfrom the command line, use vxrelayout options:-0 slow=iodelay

Use this option to reduce the system performance impactof copy operations by setting a number of milliseconds todelay copy operations.

• The process runs faster without this option.

-0 iosize=size• Use this option to perform copy operations in regions with

the length specified by si ze.

• Specifying a larger number typically causes the operationto complete sooner, but with greater impact on otherprocesses using the volume.

ContrOlling the Task Progress Rate

VxVM provides additional options that you can use with the vxrelayoutcommand to pass usage-type-specific options to an operation. These options canbe used to control the 110 rate for mirror copy operations by speeding up orslowing down rcsynchronization times.

The iodelay option reduces the system performance impact of copy operations.Copy operations are usually a set of short copy operations on small regions of thevolume (normally from 10K to 118K). This option inserts a delay between therecovery of each such region. A specific delay can be specified with iodelayas anumber of milliseconds. The process runs faster when you do not set this option.The default value of the delay is 150ms.

The iosi zeoption performs copy operations in regions with the length specifiedby size, which is a standard VxVM length number. Specifying a larger numbertypically causes the operation to complete sooner, but with greater impact on otherprocesses using the volume. The default I/O size is I MH.

Caution: Be careful when using these options to speed up operations. becauseother system processes may slow down. It is always acceptable to increase theslow options to enable mort: system resources to be used for other operations.


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Controlling Task Progress: VEARight-click a task in the Task History window,and select Throttle Task.

10.180.208.182 - Th

You can also set the slow attribute in the vxtask command by using the syntax:vxtask [-i task_idl set slow=value

Throttlng velue: Ii jJ I ';":'I:::':"~:" :'''1' I ~L .1.....'. I ,J I I I .! ..,~...! Set the throttling

: value in the Throttle: Task dialog box.

You can reduce the priority of any task that is time-consuming. Right-click the taskin the Task History window, and select Throttle Task. In the Throttle Task dialogbox, use the slider to set a throttling value. The larger the throttling value, the moreslowly the task is performed.

n The iorgO( tho throttling volue is, the slower the.., taskwne.

(""".1 Help

5-20

01(

Slowing a Task with vxtask

Throttling a Task with VEA

Copvnqtu '~- 2006 Syruautec Corporation Ail fights reserved

VERITAS Storage Foundation 5.0 for UNIX. Maintenance

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What Is Storage Expert?

VERITAS Storage Expert (VxSE) is a command-line utilitythat provides volume configuration analysis.

Storage Expert:• Analyzes configurations based on a set of "rules" or VxVM

"best practices"• Produces a report of results in ASCII format

• Provides recommendations, but does not launch anyadministrative operations

Analyzing Volume Configurations with Storage Expert

What Is Storage Expert?

As your environment grows. your volume configurations become increasinglycomplex. You should monitor your configurations to ensure appropriate faulttolerance. layout. recovery time. and utilization of storage. Checking each volumemanually to verify that you have appropriate storage layouts can be a time-consuming task.

The VERITAS Storage Expert (VxSE) utility is designed to help you locate poorvolume configurations. monitor your volumes. and provide advice on how toimprove volume configurarions Storage Expert is a command-line utility that isincluded as part ofVxVM. Storage Expert provides volume configuration analysisbased on a set of configuration rules that compare your volumes and disk groups toVxVM "best practice" management policies. Storage Expert reports the status ofyour volumes compared to the rules and makes recommendations, but docs notlaunch any VxVM administrative operations.

Storage Expert consists ofa set of scripts (called rules), an engine that runs thescripts (the 1"II/!!.1 eIIgille). and a report generator. When you run a Storage Expertrule, the utility:

Gathers information about your VxVM objects and configuration2 Analyzes the data by comparing it to predefined VxVM best practices3 Produces a report in ASCII format containing the results and recommendations

for your configuration

Administrator:Are al\ of my logsmirrored?Are al\ of myvolumes redundant?Should my mirror-stripebe a stripe-mirror?

Report:INFO

VIOLATIONPASS


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What Are the Rules?

Storage Expert contains 23 rules. Rules provide answers toquestions about:• Resilience

Do my mirrored volumes have DRLs? (vxse_drll)

- Is my RAID-510g appropriately sized? (vxse_raid51og2)

• Disk groups and associated objects- Are all of my disk groups of the current version? (vxse_dg4)

- Are all of my volumes redundant? (vxse _redundancy)

- Is my disk group configuration database too full? (vxse_dgl)

Striping- Are my stripes an appropriate size? (vxse_ stripesl)

- Do my striped volumes have too few or too many columns?(vxse_stripes2)

• Spare disks- Do I have enough spare disks? (vxse_spares)

- Do I have too many spare disks? (vxse _spares)

What Are the Storage Expert Rules?

Storage Expert currently contains 23 rules. Each rule performs a different check onyour storage configuration. A complete list of Storage Expert rules, theircustornizablc aunbutcs. and default values is included at the end ofthis section.


Copyr:gnt ;,:006 Svruanter- Corpornucn 1\11fOg/Its reserved

symantec.~.<Running Storage Expert Rules

• VxVM and VEA must be installed.• Rules are located in !opt!VRTS!vxse!vxvm. Add this path to

your PATH variable.

• Syntax:rule_name [options] {info llist I check I run}

In the syntax:- info- list- check

Displays rule descriptionDisplays attributes of ruleDisplays default valuesRuns the rule- run

• In the output:- INFO

- PASS- VIOLATION

Information is displayed.

Object met rule conditions.Object did not meet conditions.

Running a Storage Expert Rule

Storage Expert rules are located in the / opt /VRTS /vxse / vxvm directory. Addthis path to your PATH environment variable before running a rule.

Notes:By default. output is displayed on the screen. but you can redirect the output toa tile using standard UNIX redirection.You can also set Storage Expert to Dill as a cron job to notify administratorsand automatically archive reports.


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To run vxse_raid51og1 on the datadgdisk group:

vxse_raidSlogl -g datadg run

Running Storage Expert: Examples• To display adescription of the vxse_raid51oglrule:

vxse_raidSlogl info

VxVM vxse:vxse_raidSlogl: INFO: vxse_.raid51og1 -DESCRIPTION

This rule checks for RAID-S volumes which do not havean associated log

VxVM vxse:vxse_raidSlogl: INFO: vxse_raid51og1 - RESULTS

vxse raidSlogl VIOLATION:Disk-group (datadg) RAIDS volume (raidSvol) does nothave a log

Examples of Rules

Displaying Tunable Attributes of a Rule: Example

SOIllC rules compare:V.xVM object characteristics against a set ofdefined attributevalues. For example. the:vxse_spares rule checks that the number of sparedisks in a disk group is within the VxVM best practices threshold.

To determine what that threshold is. you can display information about theattributes of the rule by using the list keyword. For example:

vxse spares list

Displaying Default Attribute Values of a Rule: Example

To display the default value of the attributes for the vxse_spares rule. use thecheck keyword:

vxse spares check

The:output indicates that when you run the vxse_apa r e s rule. you receive awarning i I' the number of sparc disks in the disk group is less than 10 percent orgreater than 20 percent.


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Customizing Rule Defaults

You can run a rule against different attribute values by:• Specifying an attribute value in the run command:

vxse_drll run mirror_threshold=4g

• Running Storage Expert against a user-created defaultsfile:vxse_drll -d /etc/vxse.myfile run

Modifying the Storage Expert defaults file:

1. Open the /etc/defaul t/vxse defaults file.

2. Delete the comment symbol (II) from the line thatcontains the attribute you want to modify.

3. Type a new default value and save the file.

Customizing Rule Default Values

You can customize the default attribute values used by Storage Expert rules tomeet the needs of your environment by using om: of several methods.

To run a rule with an attribute value other than the default. YClU can specify therule attribute and its new value on the command line when you run the rule.

For example. in the vxse_drll rule. the mirror_threshold attribute is IGB by default. This rule issues a warning if a mirror is larger than I GB anddocs not have an attached dirty region log. To run the vxse_drll rule with adifferent mirror threshold value of 4 GB:

vxse drll run mirror threshold=4gTo run Storage Expert niles against a user-created defaults tile. you create anew defaults tile with customized attribute values. then specify the tile in thecommand line using the -d option.

For example, to run the vxse_drll rule against the user-created/etc/vxse .myfile defaults tile:

vxse drll -d let c/vxse.myfile runTo change the default value of an attribute in the Storage Expert defaults tile:

a Open the /etc/default/vxse defaults tile.

b Delete the comment symbol (#) from the beginning of the line that containsthe attribute that you want to modify. (You can also specify values that areto be ignored by inserting a # character at the start ota line.)

c Type a new value for the attribute and save the file.When you run the rule again. the new value is used for that rule by default.

----------------.--------------------------------


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syrnantec

Lesson Summary

• Key PointsThis lesson described how to perform onlineadministration tasks, such as changing the layout of avolume, and how to analyze volume configurationswith the Storage Expert utility.

• Reference Materials- VERITAS Volume Manager Administrator's Guide- VERITAS Storage Foundation Release Notes

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Lab 5: Volume MaintenanceIn this lab, you practice volume maintenanceactivities, such as changing volume layoutsand using the Storage Expert utility.Optional exercises provide additional practiceon managing VxVM tasks.

I For Lab Exercises, see Appendix A.~or Lab Solutions, see Appendix B.

Labs am! solutions tor this lesson arc located 011the following pages:

Appendix A provides complete lab instrucuons. "I.nb ': Volll",e \hilliVlld!lc·"'"p,lgi..' r\""f)

Appendix B provides complete lab instructions and solutions. "Lub " S,.ittll<Olh:\"ulumc \'hi!ltl:ll~!ilL'~:," pill:1l' d·,(1)

5-26COp/Jly!l! c;, 2on6 Syuvanter. Corporation All rights reserved

VERITAS Storage FOlilldation 5.0 for UNIX: Maintenance

Lesson 6

Performance Monitoring

syrnante,

• Lesson 1: Maintaining DataConsistency




• Lesson 5: Volume Maintenance~J:!!!.s..~'!..~:_p'!!!!..O!.man~~M_~!torin~_• Lesson 7: Point-in-Time Copies• Lesson 8: Other Enterprise Features

Overview

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Lesson Topics and ObjectivesTopic After completing this lesson, you

will be able to:Topic 1: Storage Identify the main steps in a storagePerformance Analysis performance analysis process.ProcessTopic 2: VxVM Monitor disk and application 110 byPerformance Monitoring using the vxstat and vxtraceTools and Techniques utilities.

6-2Conyf!Jnt!, 2006 Symasuec Corror.mon All flghls reserved


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Storage Performance Analysis Process

IIUnderstand your I Identify the

application I complete dataworkload and .j..; I/O path from IIperformance application toobjectives. disk.

)

Determinetheoretical

performancecharacteristics

for eachcomponent.

Measureperformance of

each componentusing available

tools.

These steps are detailed on the following slides.

Storage Performance Analysis Process

Performance Analysis Process

Storage performance analysis involves these main steps:Understand your application workload and your performance objectives foreach application workload.

2 Identify all components of the data transfer model of your storage architecture,that is. the complete I/O path of your data from application to disk.

3 Determine the theoretical performance characteristics of each component foreach of the hardware components in your architecture.

4 Use performance monitoring and workload generation tools to measureperformance for each of the components in your configuration.

Lesson 6 Performance Monitoring

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Step 1: Understanding Your Application Workload

Workload Type I/O Size? Random or ReadlWrlte Mix?SequentialI/O?

Email server Small Random Mixed reads andwrites

Online Small (typically a single Random Mixed reads andTransaction database block for reads; writesProcessing a small set of database(OLTP) blocks for writes)

Decision Support Large Sequential ReadsSystem (OSS)

Backup and Small Sequential Reads for backupRestore operations; writes

for restoreoperations

Image/scientific Large Sequential Mixedprocessing

Web server Small (although some Random Readsgraphics may be large)

Step 1: Understanding Your Application Workload

Your best guidance in performance tuning comes from understanding how yourapplications work. Which applications arc you running and what arc thecharacteristics of the application workloads')

Example application types and workload characteristics arc displayed in the slide.

Before you begin to analyze storage performance, you should know the answers tothe following questions about your applications:

What is the [/0 size'!

Is the 1·0 operation-intensive ur data content-intensive?

Is the 1/0 pattern random or sequential"

What is the mix of reads vs. writes')

Does the application work to file system interfaces. raw purtiuous. or both?

Arc shared data access implcmcntauons involved?

What arc the performance objcctiv cs tor each application workload?


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's)~;~tec.

Step 2: Understanding the ItO Data Transfer PathDirect-

AttachedDisk

Direct-Attached

Array

SharedAccessArray

StorageArea

Network

f····tJApp

DataBus

. Disk 1"'(lAPPDataBus

Disk,Disk,

App

DataBus

ArrayCtlr

DataBusDisk

Disk,L- __ -' Disk,

Step 3: Determine the theoreticalperformance characteristics ofeach component in yourconfiguration.

Disk

Disk

Step 2: Understanding Your I/O Data Transfer Path

In addition to understanding your applications. you must also have acomprehensive understanding of your storage architecture and the complete 1/0path from the application to the underlying disks.

Example data transfer models are displayed in the slide. including direct-attacheddisk, direct-attached array, shared access array. and SAN models.

Each hardware or software layer in the data flow presents a possibility forperformance analysis and tuning. You determine overall performance byexamining all components within the path of an 1,'0.

Step 3: Identifying Theoretical Performance Limits

For each of the physical components in the data flow, you can identify thetheoretical performance characteristics. These performance characteristics areusually included in the hardware product data sheets of the products. Thesetheoretical limits can be used as a baseline for further performance analysis.

lesson 6 Performance Monitoring

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Step 4: Using Performance Analysis Tools

• Use performance analysis tools to generate sampleloads and identify performance limits for eachcomponent in your configuration.

• Two types of tools are available:- Workload generators: Used to simulate a typical

workload of an applicationExamples: vxbench,PostMark, dd, tar, custom Cprogram, bpbkar (NetBackup)

- Performance statistics tools: Used to monitorperformance and measure how fast 110movesthrough a configurationExamples: vxstat, vxtrace, vmstat, iostat, sar,sag,switch port stats, array tools

Step 4: Using Performance Analysis Tools

The ideal performance analysis involves running the actual application that usesthe hardware to generate an I/O load that you can analyze. However, due to thecomplexity of I/O patterns, analyzing performance by running the actualapplication can be difficult.

By using tools to generate 1/0 loads. you can investigate and combine particularaspectsof the 1/0 in a controlled manner. Examples of load generators include:

dd: Although not ideal for a complete analysis, dd provides a quick way togenerate sequential 1/0 operations using specific l.O sizes.vxbench: vxbench is a free utility created by VERITAS that you can usein performance analysis to generate a wide variety of workloads (random.sequential. mixed. multithreaded. and so on). This utility hasmany options thatenable you to control the generated IiO. vxbench is available from:ftp://ftp.veritas.com/pub/support/vxbench.tar.ZC program: You can create your own C program to generate 1/0.

Other benchmarking tools. such as PostMark. arc available as shareware.

VxVM utilities (covered later in this lesson) that you can use to analyzeperformance include:

vxstat: You can display statistics lor volume. plcx, subdisk. and disk activityfor specific intervals of time by using the vxstat utility.vxtrace: You can display information about individual I/O operationsperformed on a volume. disk group. or other named object or device by usingthe vxtrace utility.

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~.~-..,The vxstat Utility

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Analyze performance for the disk used by the testOl volume:vxstat -i 1 -d testOl

OPERATIONS BLOCKS AVGTIME (ms)

TYP NAME READ WRITE READ WRITE READ WRITEI".'-''"--''~

, After the firsti invocation of Tue 30 Jul 2004 09:35:25 PM eST! the 1/0 dm datadg01 64 0 4096 0 15.8 0.0I program Tue 30 Jul 2004 09:35:26 PM eST

dm datadg01 62 0 3968 16.1 0.0

After four -. f Tue 30Jul'2004 09: 35: 38 PM eST

[ Invocations dm datadg01 78 0 4992 51. 2 0.0Tue 30 Ju1 2004 09:35:39 PM eSTdm datadg01 78 0 4992 51. 5 0.0 ,---- _____ ~_~___.J

After sixTue 30 Jul 2004 09:35:46 PM eST

invocationsdIn datadg01 78 4992 76.5 0.0Tue 30 Jul 2004 09:35:47 PM 8STdm datadg01 76 0 4864 78.9 0.0

VxVM Performance Monitoring Tools and Techniques

The vxstat Utility

To display statistical information on volumes. plcxes. suhdisks. or disks. you canuse the vxstat command. The vxstat utility analyzes completed VolumeManager-initiated II0s per sample time increments. The first output from vxstatdisplays information since the last reboot or the last reset operation.

When performing hardware benchmarking, you should use vxstat to displaystatistics for disk devices.Displaying the statistics for plexcs and volumes is notvaluable because the number of I/O operations fur plexes and volumes isconstrained by the underlying disks. Yon can use the output ofvxst at incalculating drive or controller throughput. comparing drive performance, andanalyzing the balance of the I '0 load across the drives.

The syntax for the vxstat command is:

vxstat [-dpsv) [-f fields) [-g diskgroup) [-i intervall-c count)) [-r) [object ... )

Use -dpsv in any combination to display statistics for disks (dl, plcxes (pl.subdisks (S), or volumes (v) associated with the object.

Use - i interval to display statistics after every interval seconds. Addthe - c count option to stop printing interval statistics after count times.

Use the - r option to reset statistics instead of printing statistics.

Use the - f fields option to select specific statistics to display.

object call be the name of a volume. plex. subdisk, or disk.


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vxstat: Measuring Drive Performance

Before analyzing performance. you should be familiar with the volumecontigurarion.Thc vxprint command displays configuration information for avolume. When analyzing the volume configuration. consider the volume layout,layout characteristics, and size of the volume.

By generating an 1/0 load and running the vxstat utility, you can analyze driveperformance. For example. assume that multiple invocations of a c program areused to perform random reads of size 32Kon the testOl volume. While the loadgeneration program is running. you can use vxstat to display statistics. Theexample displays statistics every second. In the vxstat output. the maximumthroughput of the drive is reached when the number of 110operations per intervalstops increasing.

vxstat: Measuring Controller and Host Adapter Performance

Measuring controller and host adapter performance is similar to measuring driveperformance:

Analyze each drive on the controller by adding a load to each drive until thenumbers in the vxstat output for each drive stop increasing.

Calculate the sum of the throughput of the individual drives. The total is theapproximate maximum throughput of the controller and host adapter.

Calculating the Throughput

To calculate the throughput of the drive (in bytes/second), use the formula:

~ No. of Blocks x 512 bytes/block lL~o of I/OOP"abo"',~:;e",ge I/OTime(m')~ J x

No. ofParallel I/Oson the Disk

In the example. the throughput lor the datadgO1disk is:

l4992 blocks x 512 bytes/block 1(

78 I/Os x 51 2 ms ) x 4 parallel I/Os

1000

2560000 bytes/sec -r- 1048576 bytes 2.4 MB/sec

Note: On HP-liX. use 1024 bytes/block.


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Operations BLOCKS AVG TIMEREAD WRITE READ WRITE READ WRITE

Tue 30 Ju1 2004 06:05:56 PM BSTdm datadg01 0 129 0 16512 0.0 45.5dm datadg02 0 153 0 19584 0.0 114.6dIn datadg03 0 0 0 0 0.0 0.0dm datadg04 0 0 0 0 0.0 0.0

! Totallias: 2821 [Total Black~:-3s0961Tue 30 Ju1 2004 06:08:13 PM BSTdm datadg01 0 130 0 16640 0.0 53.3dm datadg02 0 133 0 17024 0.0 52.1dm datadg03 0 145 18560 0.0 68.4dm datadg04 !L~i8l 0 0 0.0 0.0

i Totallias: ~ I TotalBlocks:52224JTue 30 Ju1 2004 06:10:34 PM BSTdIn datadg01 108 0 13824 0.0 32.1dm datadg02 0 140 17920 0.0 65.0dm datadg03 0 135 17280 0.0 53.2dm datadg04 Q 114 0 14592 0.0 38.2

I TalaI lias: 4971 [!atal Blocks: 63616 1

~vxstat: Load Balancing and Volume Layout

vxstat: Load Balancing and Volume Layout

Load balancing is the process of assigning data to physical drives in order toevenly balance the 110 load among the disk drives. Load balancing does notguarantee optimal performance and is not a substitute for complete analysis.

In the example. vxs ta t is used to analyze three different volume layouts:The volume striped across two columnsThe volume striped across three columns (One more column is added toincrease the bandwidth and decrease the load on datadgOl and datadg02.)

Thc volume striped across four columns (One more column is added. resultingin a four-way striped volumc.)

By comparing the vxstat output for the three volume layouts. you observe:As more columns are added to the volume. the total number of 1/0 operationsand blocks transferred per analysis interval increases.The load on an individual drive decreaseswhen the number of columns isincreased from two to three.

As you add more columns. the rate per drive begins to decrease, and the totalnumber of IIOs stabilizes for the volume. indicating that adding more columns willnot improve performance. You can use the -v option of the vxstat command todisplay the total number of l/Os sent to the volume.


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dm datadgOldm datadg02dm datadg03dm datadg04

221310

! 7680.~' .0l'3328 02560 0

o 0

-------A disk group contains two volumes: test and test2.

v test ENABLED ACTIVE 204800 SELECT test-Ol fsgenp1 test-Ol test ENABLED ACTIVE 360928 STRIPE 3/32768 RWsd datadg02-01 test-Ol datadg02 1007 98784 0/0 cltOdO ENAsd datadgOl-Ol test-Ol datadgO1 0 98784 1/0 clt2dO ENAsd datadg03-01 test-Ol datadgO3 0 98784 2/0 cl tlOdO ENA

v test2 ENABLED ACTIVE 204800 SELECT fsgenp1 test2-01 test2 ENABLED ACTIVE 205632 CONCAT RWsd datadgOl-02 test2-0l datadgOl 98764 205632 0 clt2dO ENA

To improve the balance of 110, off-load some data to the unuseddatadg04 drive by using vxassist move:

vxassist move test !datadgOl datadg04

vxstat: Load Balancing for an Overused Disk

In this example, the volume named test is striped across three disks. When yourun the vxstat command, notice that datadgOl has a disproportionate amountof I/O compared to the other disks.

In the output ol'vxstat, notice that the average I/O time per operation is muchhigher on datadgO 1 compared to the other drives:

datadgOl has an average' I/O time of 133.~ milliseconds,datadg02 has an average 1.0 time 01'45.4 milliseconds.

datadg03 has an average I/O time of 55,0 milliseconds,

One disk with a disproportionate amount of 110 docs not necessarily indicate aperformance problem. However, when you note that datadgO 1 is also operatingnear its maximum transfer rate. you should suspect that datadgO 1 is overused. Ina local context, striping across three disks is better than striping across two disks.Howcx CI". in this case. striping across three disks decreases performance, becausethe datadgOl disk is overloaded.

Because there is an available drive. you should examine the volumes usingdatadgOl and determine whether you can offload some of the data to the unusedda tadg04 drive.


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By using the vxt race command, you can view multiple processes, measure howmany columns arc needed, and verify if the stripe unit is appropriate:

vxtrace [-g diskgroup] [-aeE] [-b buffersize][-c eventcount] [-d outputfile] [-f inputfile][-0 objtype [, objtype] ",] [-t timeout] l-w waitinterval][name I device] , , ,

In the syntax, you use the -0 option to specify the type of trace data to collect. Forexample, -0 dev traces virrual disk I:Os, and -0 disk traces physical disk liOs.To collect the trace data that is associated with a specific VxVM object, such as avolume, you type the name of the object (name) at the end of the command.

The vxt race utility uses a circular buffer. Always use the -d option to dumprecords to a tile. Then, use the - f option to read the records.

1 Dump trace data on virtual and physical disk I/Os for the volume nameddatavol to the file named /tmp/filel.out:

vxtrace -d /tmp/filel.out -0 dev,disk datavol2 Stop tilling the tile:

Press Ctrl+C.

3 Read the trace records from the tile named /tmp/ f ilel . out:

vxtrace -f /tmp/filel.out -0 dev,disk datavol I more

You can use the -t timeout option to stop collecting trace data after timeoutseconds, or press Ctrl+C to stop the tilling of the tile. (Pressing Ctrl+C can causethe last few records to be discarded.)

The vxtrace Utility

The vxtrace utility enables you to:• View multiple processes.• Measure how many columns are needed.• Verify if the stripe unit is appropriate.

To run the vxtrace command:

1. Dump trace data to a file:vxtrace -g diskgroup -d file_name -0 de v s dLak \vol ume_name

2. Stop filling the file with trace data:Press Ctrl+C.

3. Read trace data from the file:vxtrace -9 diskgroup -f file name -0 dav,disk \volume_name I more -

The -0 dev, disk option selects trace data on virtual (dev) andphysical (disk) devices.

The vxtrace Utility

Lesson 6 Performance Moniloring

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Selecting a Stripe Unit Sizesymantec.

If the SU size Is muchgreater than 1/0 size,each I/O is more IIkety tobe contained within onecolumn.Most 1/0 operations aresatisfiad by a single diskI/O. This increases thenumber of concurrent 1/0operations that can beperformed.

As a guideline:

1/0 size:n x Full Stripe Width

where n Is a positiveinteger.

vxassist -g diskgrollp [-b) relayout volumestripeuni t= (neh'_sl ripe _uni t_ S1 z e l

Random 1/0Goa I: Perform acomplete 110onone column.

If the SU size is too small,each 110goes to twocolumns.Two disk 110operationsare required instaad ofone. This reduces thenumber of concurrent 110operations that can beperformed.

Sequential 110Goal: Use alldrives for asingle 110.

To use all drives for asingle I/O, the fullstripe width should beless than the I/O size.

Stripe Unit Size: Random 1/0

Fur a multithreaded random I/O application, such as a multiuser file system, thegoal is to perform a complete I/O on one column. To achieve this goal, the stripeunit sizc should be much greater than the 1'0 size,

The reason to use striping lor multithreaded random I 'O is to allow multiple l/Osto complete simultaucously. A good stripe unit size depends un how often you arcwilling tu allow the I/O to be broken up. Determine the percentage of time that youarc willing to allow the I/O If) be broken up and multiply the I 'O size by 100divided by the percentage. Round the result up to the nearest power of two todetermine the stripe unit size,

Stripe Unit Size = I/O size x IOO/peralllage. rounded up to a power of two

Stripe Unit Size: Sequential 1/0

For single-threaded sequential l.O, such as database batch-type applications, thegoal is tu use the maximum available bandwidth for a single JlO so that the I/Ocompletes much laster.

For example. instead of sending a single l/O of size 25hK to a single drive, youbenefit from the additional band" idth by sending four I/Os of size 64K to fourdifferent drives simultaneously.

However. the increase in the performance is not directly proportional to thenumber of columns added, because each of the 64K LiO, must complete lor the256K I/O to be complete, Therefore, the overall performance is determined by theslowest of the four drives.

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VERITAS Storage Foundation 5.0 for UNIX. Maintenance6-12

Interpreting vxtrace OutputIn the vxtrace output, you can trace 1/0 request 1001 fromthe user, to the volume, to the disk, and back again:

vxtrace -g testdg -f /tmp/file,out -0 dev,disk I pg1001 START write vdev datavol block 129152 Ien 64 ...10002 START write disk devicel op 1001 block 66880 Ien 6410002 END write disk devicel op 1001 block 66880 Ien 641001 END write vdev datavol op 1001 block 129152 len 64 ...

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Interpreting vxtrace Output

The vxtrace utility writes 1'0 trace event records to a file in binary format, andformats the trace data when you read the file using the - f option. For example:

vxtrace -g testdg -f /tmp/fi1e.out -0 dev,disk I pg

In the output. each 110 is assigned a request ID. represented by the number at thebeginning of each line of output. You can follow the request ID through the outputto trace the path of the 110 from the user to VxVM. from VxVM to the disk, andback again.

STARTwrite vdev indicates the start of the write 1101001 to the virtualdevice datavol, starting at block 129152 for a length of 64 sectors (J2K onSolaris).

concurrency indicates the number of concurrent processes that arc detected.This number increases as additional processes arc detected.

In the slide. concurrency is not shown due to space limitations. but the full lineof output reads: 001 STARTwrite vdev datavol block 129152len 64 concurrency 0

STARTwrite disk indicates the start of the write I/O 1002 to the physicaldisk devicel, for example. cl t1dOs2 on a Solaris platform.

ENDwrite disk indicates the completion of the write 1101002 to thephysical disk.

ENDwrit e vdev indicates the completion of the write I/O 100 I from thevolume.

• START wri te vdev indicates the start of the write 110 1001 tothe virtual device da tavol, starting at block 129152 for alength of 64 sectors (32K on Solaris).

• START wri te disk indicates the start of write 110 1002 to thephysical disk devicel.

• END wri te disk indicates the completion of write 110 1002 tothe physical disk.

• END write vdev indicates the completion of write 110 1001from the volume.


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vxtrace: Analyzing the 1/0 ProfileThe test volume has a concatenated layout on the cltldOs2drive. Start vxtrace, generate sample 1/0, stop the trace, andanalyze:. ..__ ...

~xtrace -g testdg -d /tmp/output -0 dev,disk testIPress Ctrt+C after the test is complete.jvxtrace -g testdg -f /tmp/output -0 dev,disk I mor

I

i------------------------------~

30147 STARTread vdev test block 115648 len 32 concurrency 0 pid 5430148 START read disk clt.ldOs2 op 3014" block 115648 len 32

30149 STARTread vdev test block 86976 len 32 concurrency 0 pid 5730150 ST-ARTread disk cltldOs2 op 30149 block 96976 len 3230148 ENDread disk cltldOs2 op 30147 block 115648 len 32 time 130147 ENDread vdev test op 30147 block 115648 len 32 time 130151 STARTread vdev test block 151232 len 32 concurrency 0 pid 6030152 STARTread disk cltldOs2 op 30151 block 151232 len 3230153 STARTread vdev test block 29472 len 32 concurrency 0 pid 5430154 START read disk cltldOs2 op 30153 block 29472 len 3230150 ENDread disk cltldOs2 op 30149 block 86976 len 32 time 230149 ENDread vdev test op 30149 block 86976 len 32 time 2

vxtrace: Process for Analyzing the 1/0 Profile

To analyze the application 10 profile by using vxtrace. you can follow thisprocess:

Analyze the existing volume layout.2 Start a trace on the volume by using vxt race.

3 Generate test I/O that simulates application performance.4 Stop the trace on the volume and analyze the vxtrace output to determine the

application 1/0 profile.5 Based on the application I/O profile, make changes to the volume layuut to

improve performance.6 Rerun the test I/O and vxtrace to determine the impact ofthe changes.

The following examples illustratc this process.

vxtrace: Analyzing the I/O Profile

The test volume has a concatenated layout on the cltldOs2 drive.

In thc output, you can determine the number of concurrent processesrunningagainst the volume by counting thc number of STARTvdev entries that do nothave ENDvdev entries. In this example, there arc at least three concurrentprocesseson the volume named test. The LU is occurring in lengths of 32sectors ( 16K 011 Solaris).


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vxtrace: Analyzing the 1/0 Profile (continued)To improve performance, change the volume layout to striped:

vxassist -g testdg relayout test layout=stripe ncol=3stripeunit=256k

Output of vxtrace after changing the volume layout:

vxtrace -g testdg -d /tmp/output -0 dev,diskPress Ctrl+C after the test is complete.vxtraee -g testdg -f /tmp/output -0 dev,disk I more

16955 STARTread vdev test block 31648 len 32 concurrency 0 pld ]11916956 START read disk clt4dOs2 op 16955 block 10656 len 3216954 END read disk clt2dOs2 op 16953 block 153392 len 32 time 116953 END read vdev test op 16953 block 154976 len 32 time 116957 START read vdev test block 128 len 32 concurrency 0 pid 212216958 START read disk cltldOs2 op 16957 block 128 len 3216950 END read disk clt2dOs2 op 16949 block 121584 len 32 time 316949 END read vdev test op 16949 block 59680 len 32 time 316959 START read vdev test block 131872 len 32 concurrency 0 pid 212516960 START read disk clt2dOs2 op 16959 block 145648 len 32

In this example. you can improve performance by changing the volume layoutfrom concatenated to striped. with three columns and a stripe unit size of 256K.

The stripe unit size is 256K to maintain an R percent break-up value:

16K x (I OO/R).rounded to the nearest power of two = 256K

Change the volume layout by using vxassist relayout. and use vxprint toverify the changes:

vxassist -g testdg relayout test layout=stripe neol=3 \stripeunit=256k

vxprint -ht test

After changing the volume layout, start the trace again. rerun the test 110. then stopthe trace when the test is complete:

vxtraee -g testdg -d /tmp/output -0 dev,disk

Press Ctrl+C after the test is complete.

When you display the vxtrace output. notice that there arc three concurrentprocesses running 011 the volume, and each process now uses a different drive tosatisfy the (10 request. The result is improved performance.

vxtraee -f /tmp/output -0 dev,disk I more


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6-15

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Possible Layout Changes

The slide lists many of the possible layout changes you may make after analyzingyour data for performance tuning.

Possible Layout Changes

What changes can you make to a volume's structure toimprove performance?

Change the RAID level of the volume.Increase or decrease the stripe unit size for a striped volume.Increase or decrease the number of columns.

Move (evacuate) a volume so that it does not share its diskswith other volumes.Reduce or make equivalent the number of volumes sharingdisks.

Identify any heavily used subdisks (hot spots) and relocate thecontaining subdisk to a lower sector offset on the disk.

If I/O is mostly read, then mirror the volume.

Combine many small subdisks into one larger subdisk.

Defragment the file system space.

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VERI7AS Storage Foundation 5.0 for UNIX: Maintenance

VxVM Tunable ParametersI Caution:1 Perform tuning changes with care.

• Tuning changes can adversely affect overall systemperformance and can make Volume Managerunusable.

• In general, default values are adequate for mostsystems.

• Before modifying tunables, back up tunableparameter files, check memory, and readdocumentation.

Solaris I HP·UX I Linu~I

VxVM Tunable ParametersVxVM has a set of tunable parameters that control the system resources used byVxVM. VxVM is optimally tuned for most configurations, but in someconfigurations, some adjustment to tuning parameters may be required to optimizeperformance. On the Solaris platform, the tuning parameters arc configured in twofiles:

• /kernel/drv/vxio.conf• /kernel/drv/vxdmp.conf

Different versions of VxVM can use different tunable parameters.

Displaying Current Tunable ValuesSularis

You can display the default value of an individual tunable parameter by using thecommand:

echo 'parameter/D' [mdb -k

echo 'parameter/E' I mdb -k (use for a M-bit kernel)

For example: echo 'vol_maxio/D'lmdb -k

You can view the internal default values of all tunable parameters by using:

prtconf -VP

In the output. unchanged tunables are listed with default values under the headingDri ver properties. Tunablcs whose value has been changed replace thedefault values in the vxio. cori f file. For example:

Copyright ~'2006 Symantec Corporation All fights -eserveo

Lesson 6 Performance Monitoring 6-17

prtconf -vP

vxio, instance #0

Driver properties:name='vol_rvio_maxpool_sz' type=int items=ldev=none value=cOxGOOOOcOO>.

name='vol_vvr_use_nat' type=int items=ldev=none value=cOx00000003>.

name='voldrl_max_seq_dirty' type=int items=ldev=none value=cOx000007dO>.

In this example. the vol_maxio parameter has been modified. Values arcdisplayed in hexadecimal format.

UP-(lX

You can display the values of tunable parameters by selecting KernelConfiguratiou-c-t-Conriguranon Parameters in the System AdministrationManager (SAM). From the command line. you can display current tunables andtheir values by using the kct une command.

To display all Volume Manager iunablcs:

kctune I grep vol

To display details about a specific tunable. use the -v option with the name of thetunable parameter to print a detailed report:

kctune -v tunable

For example:

kctune -v vol max vol

Modifying Tunable ParametersSularis

Caution: It is recommended that you do not attempt to change the default valuesoftunable parameters without consulting VERITAS Support. Before modifyingtunable parameters:

Back up the /kernel / drv /vxio. conf and/kernel/ drv /vxdmp. conf files.

Ensure that memory is available before setting tuuablcs. Expanding thenumerical values on most tunablcs demands more system memory.

Read the tunahles documentation in the appendix of this course and read aboutthe tunablcs in the IERnAS VotumeMOHLIger Svstcm Administrator '.I' Guide,

To modify a VxVM tunable. you add a line Ior the tunable in the /kernel/drv/vx i.o . conf or /kernel / drv /vxdmp. conf Ii lc and then reboot the system.Changed tunables arc then in effect.

For example, to change the tunable parameter vol_max_ vol, add the parameterand the new vuluc to the /kernel/drv/vxio, conf tile:

VERITAS Storage Foundation 5.0 for UNIK Maintenance6-18

Open the /kernel / drv/vxio. conf file in a text editor:vi /kernel/drv/vxio.conf

2 Add the parameter and its new value after the line name="vxio"parent="pseudo";.

vol_max_vol=5000;3 Save the file and quit.4 Reboot the system:

/usr/sbin/shutdown -gO -y -i6Hp·l:X

Caution: It is recommended that you do not attempt to change the default valuesof tunable parameters without consulting VERITAS Support. Before modifyingtunable parameters:

Ensure that memory is available before setting tunablcs. Expanding thenumerical values on most tunables demands more system memory,Read the tunables documentation in the appendix of this course and read aboutthe tunables in the' 'ERIT.4S ,'''/III11L' Manager Administrator ',\'Guid«.

Tunable parameters arc stored in the Istand/system file: however. you shouldnot manually edit this file. You can change the value of a tunable parameter byusing the kctune command with the t unable= val ue syntax:kctune tunable=value

For example:

kctune vol max vol=5000

By default. changes to the currently running kernel configuration are appliedimmediately. Some changes cannot be applied without a reboot: if any suchchanges are requested, or if the -h nag is given. all changes on the kctunecommand line are held until the next boot.

linux

The sysct 1 command is used to view. set. and automate kernel settings ill the/proc/sys/ directory.

Tu get all overview of all settings in the / proc / sys / directory. at root, type:

sysctl -a

net.ipv4.route.min_delay 2

kernel.sysrq = 0

kernel.sem = 250 32000 32 128

The sysct 1 command can be use in place of echo to assign values to writabletiles in the /proc/ sys / directory.

For example. instead of using echo 1 > /proc / sys/kernel / sysrq. youcan use this sysct 1 command:

sysctl -w kernel.sysrq="l"

6-19Lesson 6 Performance Monitoring

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kernel.sysrq = 1

All /proc/ sys/ special settings arc lost when the machine is rebooted. To savesettings to your kernel pennanently. add them to the / etc/ sysct 1.conf file.

Every time the system boots. the ini t program runs the /etc/rc. d/rc. sysini t script. This script contains a command to execute sysctlusing/etc/sysctl. con f to dictate the values passed to the kernel. Any valuesadded to /etc/sysctl. con f take effect each time the system boots.

To make persistent changes on Linux. you need to use the sysct 1. conf file totunc the parameters. Every time the system boots, thelet c / rc . d/ rc . sys i ni t script is executed by ini t .This script containsinstructions to execute the sysct 1command using the values in theet c/ sysct 1.conf. Therefore, any values added to / etc/ sysctl . conftake effect after the system boots.

To modify tunublcs (other than the Vx Vlvl memory tunable parameters). you needto either add a tunable to the sysct 1. con f file or edit an existing tunable In the/etc/sysctl.conf file, as follows:

vxvm.vxio.tunable name = value

For example.

vxvm.vxio.vol nm hb timeout 20

lJsing vxvol tune

Iunublc parameters may be adjusted using the vxvol tune command.

To display the \ alue of a Vx Vlvl tunablc. use:

vxvoltune vxvm tunable

To change the:value of a tunable, specify the new value: as an argument:

vxvoltune vxvm tunable value

You must then shut down and reboot the system for the change to take cllcct. Thenew value persists across system reboots until it is changed again.

For example, the following command sets the value of vol_ maxkiocount to8191:

vxvoltune vol maxkiocount 8192

Caution: The: vxvol tune utility modifies the tunable values stored in the/ etc/vx/vxvm _ t unables file. Use the vxvol tune command to change thevalues stored ill these Ilks. Do not edit these files directly,


C');Jylly~lI ~. 20uo Symanter. CorpOf;-l!lor' All nqtus reserved

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Lesson Summary

• Key PointsThis lesson described the storage performanceanalysis process for performance tuning. This lessonalso introduced VERITAS Volume Manager tools thatyou can use to analyze the performance of thehardware configurations and to tune volume layouts.

• Reference Materials- VERITAS Volume Manager Administrator's Guide- VERITAS Volume Manager Hardware Notes- VERITAS Volume Manager Troubleshooting Guide

Labs and solutions for this lesson arc located on the following pages:

Appendix A provides complete lab instructions, "Lib 11:Pt'rfllnn:lIlcc \lol1i1""'llg,"Pil)!.,' ,\.-j'l

Appendix B provides complete lab instructions and solutions. "I ,ill (, S•.•ilIiIO'h:

l'c'l'i'nrJnill1lil' ~ louitoriug." Pi;;!", Jl-','

Lab 6

Lab 6: Performance MonitoringIn this lab, you analyze Volume Manager 110operations using the vxstat and the vxtraceutilities.

For lab Exercises, see Appendix A.For lab Solutions. see Appendix B.

lesson 6 Performance Monitoring

Copyright -g} 2lJn6 Symamec Corporation 1\11flgllts reserved

6-21

Lesson 7

Point-in- Time Copies

• Lesson 1: Maintaining DataConsistency




• Lesson 5: Volume Maintenance• Lesson 6: Performance Monitoring

~ __l:e~~f1 !~l~gj!!t:Lf!:rt~fgI!Lf!!_~~~• Lesson 8: Other Enterprise Features

Overview

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Topic 1: What is a Point-In- Define a point-in-time copy.Time Copy?Topic 2: Types of PITC Comparethe five types of point-in-Solutions in Storage time copy solutions provided byFoundation VERITAS Storage Foundation.Topic 3: Creating and Create and managetraditional, full-Managing Volume Snapshots sized instant, and space-optimized

instant volume snapshots.Topic 4: Using Volume Use volume snapshots and deportingSnapshots for Off-Host and importing of disk groups toProcessing perform OHP.Topic 5: Creating and Createand managestorageManaging Storage Checkpoints checkpoints.

7-2Couvnqht t: <'OOb Syn'(lriler. Corporation /\11 fightS reserved


LiveProcess in

Applications

111 I I I 1 1 1

Primary - Primary 1- Primaryg Data Data Data

rI

e Copy Copy Copyof Data of Data of Dataat 7 a.m. at Noon at 5 p.m.

I I I

Time

Point-In-TimCopies of

Data

Reporting~ Testing! '"if~Support .:IJ

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Backup II~!I

What Is a Point-In-Time Copy?A point-in-time copy (PITe) enables you to capture an image of data at a selectedinstant for use in applications such as backups, decision support, reporting, anddevelopment testing.

Point-in-time copy solutions can additionally be configured for off-host processingto remove much of the performance overhead on a production system.

Common Uses for PITCs

Examples of common offline and off-host processing tasks that use point-in-timecopies include:

Data backup: By taking a PITe of your dura and backing up from this PITeyou can ensure that your business-critical applications continue to run withoutextended downtime and without impacting performance.Report generation: By creating a Pll C, importing it to a secondary server.and then generating billing statements, you can ensure that the performance ofthe production server is unaffected.Decision support analysis: Because information is constantly being updated,you can perform this decision support procedure on a Pl'IC of the data to avoidusing the original data.Testing: PllC data provides developers, system test engineers, and QA groupswith a realistic basis for testing the robustness, integrity, and performance ofnew applications.Training: A PlTt" of the production tiles is made, ancl the training exercisesuse the copy, rather than the original.

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Lesson 7 Point-in-Time Copies 7-3

Physical vs. Logical PITes

PhysicalCopy

PrimaryData

ABCD E FG H I

rABCD E FG H I

Copyof Data

Physical PITC:• Complete copy of the

primary data• Fully synchronized• Requires double the

space

Logical PITC:• Contains only primary

data that has changedone time

• References the primarydata

• Requires less space

LogicalCopy

ABC'D'E FG H I

r.;'[ifl! [Q] 1\ 1\ !1 A A A ~

L .!

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Physical or Logical PITC

All types of PITCs achieve a consistent point-in-time image of the data. A PITCcan be either a complete physical copy or a logical copy of the data.

Physical PlI'Cs:

The physical PITC is a physically distinct copy of data usually produced bybreaking off a mirror of the storage container.

Advantage of physical copies:The PIlC is an actual physical copy of the data.Disadvantagesof physical copies:

The PITC requires the same amount of storage space as the original.The I'ITC requires time for synchronization of data,

Lugicall'ITCs:

The logical PITe is composed by logically reconstructing data from multiplesources (original data plus a record ofsubsequent changes), The I'ITC identifiesand maintains modified blocks. and in addition. refers to the original data, ThePlTt.' is dependent on the primary copy of data,

Advantages of logical copies:- The PITC is available for use instantaneously,

Potentially less storage space is required,Disadvantage of logical copies:The PITC is dependent on the original.

7-4Copvnqh! : 2006 Symantec Conxnauon All nyhls reservec

VERITAS Storage Foundation 5,0 for UNIX' Maintenance

Physical PITes: Reads and Writes

ReadslWrites

PrimaryData

rnABC A B' C A B' CD E F f--. D E' F' - D E' F'G H I G H' I G H' I

7a.m. Noon 5 p.m.

ABC ABC ABCD E F - D E F f-- D E' FG H I G H I G' H' I

111

Copyof

Data

ReadslWrltes

Reads/writes to theprimary have noperformance impacton the copy.

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Time

Reads/writes to thecopy have noperformance impacton the primary.

Reads and Writes on PllCs

There are certain performance implications that you should consider whenperforming I/O on files that have point-in-time copies attached.

Performance Issues with Physical PllCs

The primary performance impact to consider for physical PITC's is the initialsynchronization. This is especially important when large amounts of data need tobe copied. For example, a terabyte of data can take several days to synchronize.

After this full synchronization is complete, there is very little if any performanceimpact on the original volume or the PITC' because they are separate objects.

Lesson 7 Point-in-Time Copies

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7-5

Copyof

Data

,rtr Rrn

ABC A B' C A B' C ./. A B' 00-o E F t---- o E F' - o E F' o E F'G H I G H' I G H' I II G H' I .•..

I 7 a.m. Noon Sp.m. 10 p.m. ~,\

/\ /\ /\ /\ B /\ /\ B /\ \ '-/\ B ,.J/\ /\ /\ ~ /\ /\ F f-- /\ /\ F -'-/\ /\ F V/\ /\ /\ /\ H /\ /\ H /\ /\ H ,./

Copy-on-Write No 111

Time

Logical PITes: Reads and Writes

PrimaryData

Impact Reads

Redirected Reads

Performance Issues with Logical PllCs

The logical plTe is connected to the primary data. Therefore. the I/O of a logicalPI'l'C is subject to the rate of change of the original data. The overall impact of thePlIC is dependent on the read-to-write ratio of an application and the mixing ofthe I{) operations.

Copy-on-Write

Logical PlTt,' solutions use copy-on-write (COW). With copy-on-write. if" writeis sent to the primary data. till: software first copies the original block of data to thepoint-in-time copy before the write can be completed.

Using copy-on-write, the primary data incurs double the performance impact onwrites.

Redirected Reads

Initially. the logical (lITC satisfies read requests lw checking the reference pointers(which indicate thut thc data can be found on the primary) and returning the datafrom the primary to the rcqucsung process.

If a change is made on block 1/ of the primary data. a subsequent read request Iorblock 1/ on the I'ITC is satisfied by checking the reference for block II and readingthe data from the indicated block on the PlTf. rather than Irom block 1/ on theprimary data.

7-6 VERITAS Storage FOUl/dation 5.0 for UNIK Maintenance

Life Cycle of Point-in-Time Copies

f1\ MakePllC\.:.,) (Assign Resources)

oUpdatePllC

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Time

Primary - Primary r-- Primary - PrimaryData Data ~ Data Data

I \7a.m. Noon I Sp.m. I 10 p.m., \

COPyo~LCopy 01 ---- Copy 01 ~ ('oPVofData Data Data Data

1---_._-

oUsePllC\V . Testing .It• Backup ,I,

t4'Destroy PllC\.::..J (Release Resources)

Life Cycle of PllCs

There are four general stages in the life cycle of a point-in-time copy:Make: You can create physical PITes by copying the entire contents of theprimary data and then breaking it off, or by creating an entirely new volumeand tilling it with the primary data. You can create Logical PITes by allocatingspace either in or out of storage used tor the primary data.

2 Use: You can use PITCs for many operations that require offline or otT-hostprocessing. including data backup, report generation, decision supportanalysis, database rollback. testing. and training.

3 Update: You can repopulate PITCs with new data from the primary. or you canrepopulate the primary with the original data from the PITe.

4 Destroy: You can remove PITes after you are finished with them. RemovingPITes frees the storage space so that it can be used for other operations.

7-7Lesson 7 Point-in-Time Copies

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PITes in Storage FoundationVERITAS Storage Foundation has the followiuq types of PITCs:

Traditional snapshots Volume-level Physical

Full-sized instantsnapshots " Volume-level Physical or logical

Third-mirror breakoffsnapshots Volume-level Physical or logical

Linked break-off Physical or logicalsnapshots Volume-level

Space-optimizedVolume-level Logical

instant snapshots •

Storage checkpoints • File system-level Logical~stemsnall!lAotS File &~!lte", le¥el Lug1at---• Requires FlashSnap: FastResync, Disk Group Split/Join, Storage Checkpoints

Types of PITe Solutions in Storage FoundationThis lesson introduces the point-in-time copy solutions that you can implementusing the VERITAS FlaslrSuap technology. flash Snap is included in the Enterpriseversion of Storage Foundation.

VERITAS Storage Foundation with FlashSnap provides tile following types orpoint-in-time copy solutions:

Volume-Level PITC Solutions:Full-Sized Instant Volume Snapshots

- Third-mirror Break-off Volume SnapshotsLinked Break-off Volume Snapshots

- Space-Optimized Instant Volume SnapshotsFile System-Level Solution:

Storage Checkpoints

Note: Linked break-offsnapshot volumes arc introduced with SF 5.0. They arc avariant of third-mirror break-off snapshots and they link a specially preparedempty volume to the data volume. The volume that is used for the snapshot isprepared in the same way as Ill!" lull-sized instant snapshots, However, unlike lull-sized instant snapshots. this volume can be set up in a different disk group from thedata volume. Note that linked break-off mirrors arc not covered in this course.


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Traditional Volume Snapshotsf.j\MakePITC\.:..J (Assign Resources)------~datavol

CD Update PITC

Create andsynchronize anew mirror.

Reattach and resynchronize:Refresh the snapshot, orRestore the original todata in the snapshot

newvol Clear the

EJ association tocreate anindependentvolume.

Detach themirror as anew snapshotvolume.

oUsePITC: ~~~~:~&1Remove the snapshot

f4\ Destroy PITC'.::J(Release Resources)

Traditional Volume Snapshots

The traditional type of volume snapshot that was originally provided in VERITASVolume Manager (Vx VM) is the third-mirror break-off type. This name comesfrom its original implementation by adding an additional plcx to a mirroredvolume.

When you create a traditional volume snapshot. you create a temporary mirror ofan existing volume. After the contents of the third mirror (or snapshot plex) aresynchronized from the original plexcs of the volume, the snapshot plex can bedetached as a snapshot volume for use in backup or decision support applications.

Updating Traditional Volume Snapshots

Reattach: When you reattach you can reassociate a traditional snapshot copy of avolume with the original volume. When you reattach, the snapshot plcx isdetached from the snapshot volume and attached to the original volume. Data isresynchronized so that the piexes are consistent.

Rcsynchronizotion using the original volume: Resynchronization using theoriginal volume uses the data in the original plex to resynchronize the mergedvolume,

Resynchronization using the snapshot: Rcsynchronization using the snapshotuses the data from the snapshot volume to replace the data in the originalvolume.

Lesson 7 Point-in-TimeCopiesCopyright c(, 2006 Symanter Corroranoo All ncnts reserveo

7-9

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Improving Volume Snapshots with FastResync

When FastResync' is enabled,data change objects areassociated with the volume.

DCO

During reattach orrestore operations.FastResync is usedto quicklyreassociate asnapshot plex withthe original volume.Updates to the original

volume are recorded inDCO logs and storedon disk. Resynchronization involves

applying only changed data, ratherthan performing an entire atomicresynchronization .

• Requires FlashSnap

FastResync

FastResync performs quick and efficient rcsynchronizatiou of volume snapshots.When you enable Fastkcsyuc, change maps arc stored on disk to survive reboots.Rcsynchronizauon occurs with minimal performance impact by writing onlychanged blocks.

Vl:RITAS volume Manager uses three objects to manage ht>tResync maps:

Data change object (DCO): Manages Fastkcsync maps

DCO log volume: Stores Fastltcsync maps in logs. which arc stored on disk

Snap objects: Track the relationship between volumes and their snapshots

How DoesFasrkcsyncWork with Snapshots'!

FastResync speeds up the rcsynchronization process:When you enable FastResync for a volume, a data change object (DCO) and aDCO log volume must lirst be associated with the volume. In the example, amirrored volume has two plcxcs, an associated DCO, and a DCO log volumewith two log plcxcs.

2 A snapshot plcx is created in the original volume, and a DCO log plcx isassociated with the snapshot plcx.

3 A new DCO object and DCO log volume arc created tor the snapshot volume.Snap objects arc created in the original volume and the snapshot volume.

4 If you later decide to rcsynchronizc the snapshot plcx to the original volume,the l astkcsync maps arc used,

Co!)ynghl c: 2006 Svmantec Coree-anon All ngnts reserved


Traditional VS. Instant Volume Snapshots

I.-~::InstantVolumeSnapshots:

• Can be the same sizeas the volume or just afraction of the size

Traditional VolumeSnapshots:

• Require the same amountof storage space as theoriginal volume

• Require time forsynchronization of data

• Can wait forsynchronization or havean immediate PITC

Instant Volume vs. Traditional Volume Snapshots

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Unlike a traditional snapshot created using the vxassist command, you canmake a backup of a full-sized instant snapshot, instantly refresh its contents fromthe original volume, or attach its plexes to the original volume, without needing tocompletely synchronize the snapshot plexcs from the original volume.

I f desired, you can additionally select to perform a synchronization of the snapshotvolume. This is useful if you intend to move the snapshot volume into a separatedisk group for off-host processing, or you want to turn the snapshot volume into anindependent volume.

Note: With third-mirror break-off and linked break-offsnapshots, you have to waitfor the synchronization to complete before you can initially create the snapshot.However. after the snapshot is created you can make use uf the instant feature torefresh the snapshots without waiting for synchronization.

Copynqlll/) 2006 Svmaotac Corporation All fights reserved

7-11Lesson 7 Point-in-Time Copies

f2\ Use PITC~. Testing

• Backup

You can choose to: ~I·.. d,•.• Instantly use the snapshot II

as is (logical PITC).or q

Fully synchronize with original to move the snapshot off-host (physical PITC).

Fully synchronize.and then clear theassociation to makean independentvolume.

Full-Sized Instant Volume Snapshotsf.j\ Make PITC\:..i (Assign Resourc_e-s.:-)----_

A logical PITC isinitialized thatemploys the copy-on-write technique.

Full synchronizationis not necessary.

CD Update PITCYou can quickly:• Refresh the snapshot. or• Restore the original to

data in the snapshot.

---- Remove the snapshot.

f4\ Destroy PITC\.::.,) (Release Resources)

Full-Sized Instant Volume Snapshots

VERITAS Volume Manager 4.1 introduced instant snapshots that offer advantagesover traditional volume snapshots. The benefits of instant snapshots include:

lmmcdiatc availability for use

Quick refreshment

Easier configuration and administration

Full-sized instant snapshots arc the same length as the original volume. Theprimary benelit of lull-sized instant snapshots is that the snapshot volume isavailable lor access as soon as the snapshot plcxes have been created.

Instant snapshots use copy-on-write to ensure that thc snapshot volume preservesthe contents of the original volume at the time that the snapshot is taken. Full-sizedinstant snapshots can use Fasikcsyuc to rcsynchronize with the primary volume.

Updating Full-Sized Instant "olume Snapshots

Refresh: When you refresh an instant snapshot. you overwrite it with anotherpoint-in-time copy of a parent volume.

Reattach: When you reattach a snapshot, the snapshot plcx is detached (rom thesnapshot volume and attached to the original volume.

Restore: When you restore a snapshot. the snapshot itscl I' remains unchanged.

Dissociate: Whcn you dissociate a snapshot. you permanently break theassociurion between a snapshot and ib original \ olumc and maintain the snapshotas an independent volume.


Copvuqht ,; 2006 Svmauter CJTporal,oll All nqhts reserved

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Space-Optimized Instant Volume Snapshotsf.j\MakePITC\..!..) (Assign Resources)

datavol CD Update PITCYou can quicklyrefresh the snapshot.

A logical PIlC is initializedthat employs the copy-on-write technique to writeoriginal data to a storagecache before the write iscommitted.

The storage cache can beshared among multiplevolumes in a disk group. Remove the snapshot.

CD ~~:s~~~C_I..• Backup Ii.~~

You can instantly use thesnapshot as is (logical PIlC).

f4\ Destroy PITC'.::J(Release Resources)

Space-Optimized Instant Volume Snapshots

Space-optimized instant volume snapshots use a storage cache rather thanrequiring a complete copy ofthe uriginal volume's storage space. VxVM usescopy-on-write to preserve the original data contents in the cache before a write iscommitted.

Because the storage cache can be configured to require much less storage than theoriginal volume. it is referred to as being space-optimized. If the cache becomestou full. you can configure VxVM to grow the size of the cache automaticallyusing any available free space in the disk group. Multiple space-optimizedsnapshot volumes can share a cache object.

Updating Space-Optimized Instant Snapshots

Refresh: You can immediately retake an instant snapshot at any time by using theRefresh procedure. Refreshing a space-optimized instant snapshot overwrites itwith another point-in-time copy of the parent volume.

Restore: You can use an instant snapshot to reinstate the contents of a volumefrom a snapshot volume. The snapshot itself remains unchanged by the operation.

Space-optimized instant snapshots use FastResync to resynchronize with theprimary volume.


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Storage Checkpoints

Create thestoragecheckpoint.

Map/Copy-on-write techniqueis used to trackchanged btocks.

CD Update PITCTake frequent storagecheckpoints to enablerollback to more up-to-date backup images.

Coordinate checkpointswith database states

f2\ Use PITC\V Mount the checkpoint

as read-only or read-write to access it. Usecheckpoints withdatabase files, backup L -.:===~applications, or file server environmentsto back up or restore an individual fileor a file system.

Storage Checkpoints

Storage checkpoints arc a feature of VxFS that you can use to quickly create alogical copy of a Ilk system at an exact point intimc. Storage checkpoints arccreated within the same space as the primary tile system and arc actual dataobjects. Therefore, storage checkpoints arc persistent across reboots.

Storage checkpoints serve as an enabling technology for other VERITAS products:NctBackup Advanced Client. including Block-Level Incremental Backups; andDatabase Edition Storage Checkpoint and Storage Rollback.

,"ote: Storage checkpoints require the FlashSnap license.

Why LIse Storage Checkpoints'!

Common uses for storage checkpoints include:

Database environments: Storage checkpoints arc ideal for file systemscontaining database tiles.

Backup and replication solutions: Various backup and replication solutions cantake advantage of storage checkpoints. Storage checkpoints track changessince the last storage checkpoint. This Iaciliuucs applications that only need toretrieve the changed data.

High availability environments: Storage checkpoints significantly minimizedata movement and may promote higher availability and data integrity byincreasing the frequency of backup and replication solutions.

lilc server environments: Storage checkpoints can be used in a file serverenvironment so that end user, call retrieve a file that is accidentally deleted.


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Storage Checkpoints vs. File System Snapshots

Storage Checkpoints:• Are persistent

• Use free space fromprimary block device

• Make Incremental backupspossible on the block level

• Have more administrativeflexibility

• Can be mounted asread-write

• Provide good performance

File System Snapshots:• Are transient

• Require separateblock device

• Make Incremental backupsonly on the file level

Are administered like filesystems

• Are mounted asread-only

• Can slow performance

Storage Checkpoint vs. File System Snapshots

The following table compares storage checkpoints with tile system snapshots:

Charactcrlstic Storage Checkpoints rile System Snapshots

Oat" persistency Persistent: available ufler areboot or system crash

Transient: lost if the file systemis unmounted or if the system isrebooted

1Ises the tree space from theprimary block device:maintains a relationship withother checkpoints:

~------------1--------------------4-----------------------Incremental backups possible lncrcmcntal backups only onon block level file level

Data storage

Uackup

Requires a separate volume forsaving before- images

Administration Has more administrativeflexibility: coordinates withOrac le states: call beadministered in multiples: canbe removed or rolled back

Accessibility Can be mounted as read-write

Is a read-only file system that isadministered like a file system

Are mounted as read-only

Performance Good file SYS1Cill performance Slower tile system pCrf~1I111anCe

Lesson 7 Point-in-Time Copies 7-15

Types of Storage Checkpoints

You can create the following types of storage checkpoints:

Data Storage Checkpoints

A data storage checkpoint is a logical image of the Ilk system at the time thestorage checkpoint is created. This type of storage checkpoint contains the filesystem mctaduta and file data blocks. You can mount, access, and write to a datastorage checkpoint just as you would to a tile system.

Nudata Storage Checkpoints

A nodata storage checkpoint only contains file system mctadata; this type ofstorage checkpoint docs not contain any file data blocks. As the original filesystem changes, the nodata storage checkpoint records the location of everychanged block.

RemovabteStorage Checkpoints

A removable storage checkpoint can "self-destruct" under certain conditions whenthe file system runs out of space. After encountering certain conditions, the kernelremoves storage checkpoints to free up space for the application to continuerunning on the file system.

Nunmouutable Storage Checkpoints

A nonmountablc storage checkpoint cannot be mounted. You can use this type ofstorage checkpoint as a security feature that prevents other applications Irornaccessing the storage checkpoint and modifying it.


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Creating and Managing Traditional Volume Snapshots

Create:vxassist -g diskgroup l+b l snapstart orig_ volvxassist -g datadg -b snaps tart datavol

vxassist -g r!iskgroup snapshot [orig_ vol) [snap_vol)

vxassist -g datadg snapshot datavol snapvol

Reassociate:vxassist -g datadg snapback snapvol

or

vxassist -g datadg -0 resyncfromreplica snapbacksnapvol

Dissociate:vxassist -g datadg snapclear snapvol

Destroy:vxassist -g datadg remove volume snapvol

Creating and Managing Volume Snapshots

Creating and Managing Traditional Volume Snapshots: CLI

To create and manage traditional volume snapshots:Create a snapshot mirror,The vxassist snapstart task creates a write-only backup mirror that isattached to and synchronized with the vol lime to be backed lip.The process runs until the mirror is created and has been synchronized. Themirror continues to be updated until it is detached during the snapshot phase.The -b option runs the snapstart process in the background.

2 Create the snapshut volume.This task detaches the snapshot mirror from the original VOIU111C, creates a newvolume. and attaches the snapshot mirror to the snapshot volume The state ofthe snapshot is set to ACTIVE. If the snapshot procedure is interrupted. thesnapshot mirror is automatically removed when the volume is started.

Resynchf romrepl ica is an offline operation that resynchronizes the originalvolume with the content of the snapshot. III effect. this is a disk-based restoreoperation which enables the lost volume to be immediately available. therebycontributing to high availability.

Lesson 7 Point-in-Time Copies 7-17Copyrtght f nlOC Symantec Comcranon. All r,qht~ reserved

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D splaying Traditional Volume Snapshot Informationvxprint -g datadg -ht I I •. Before snapshot is detached,

v datavol ENABLED ACTIVE 40960 SELECT fsgenp1 de c evoa c m. datavol ENABLED ACTIVE 40960 CONCAT

sd datadgOl-Ql datavol-Ol datadgOl 0 40960 0 e i eaeop1 datavol-02 snapvol SNAPDONB40960 CONCAT

sd datadg02-01 datavol-02 datadg02 0 40960 0 clt2dl

I After snapshot is detached Idg datadg default default 20000 1110487068.43 trainS

dm datadgOl clt2dOs2 auto 2048 10404096dm datadg02 clt2dOs2 2048 10404096dm datadg03 c i eaeosa auto 2048 10404096dm datadg04 clt2dOs2 auto 2048 10404096 Original volumev c1atavol KNABLl:D ACTIVI 40960 SILICT f.genp1 c1atavol-Ol datavol •••••• L&Il ACTIV.I 40960 CONCAT RW.d datat1g01-01 d.ataval-Ol c1atadgOl 0 40960 cltllSO

"""v snapval ENABLED ACTIVB 40960 ROUND lsgenp1 datavol-02 snapvol ENABLED ACTIVE 40960 CONCAT >wsd datad.g02-01 datavol-02 datadg02 0 ~J!~§JL~,Jt~_..._._. clt2dl EN.

Snapshot volume l

Displaying Traditional Volume Snapshot Information

You can use vxprint to display information about volumes and their associatedtraditional volume snapshots.

Copynqtu s: ~006 Seuaruec Corpo.ano-' All nqnts reserved

VERITAS Storage Foundeuon 5.0 for UNIX: Maintenance7-18

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Preparing to Create a Full-Sized or Third-Mirror Break-offInstant Volume Snapshot: CLI

Enable FastResync:

vxsnap -g diskgroup [-b] prepare orig_volvxsnap -g datadg prepare datavol

Allocate the storage using one of these methods:

Third-mirror Break-off:

• Add a mirror to use for third-mirror break-off snapshot:vxsnap -g diskgroup addmir volume_name

• Use an existing ACTIVE plex in the volume.

Full-sized Instant:

Create an empty volume to use as a full-sized instantvolume snapshot.

Preparing to Create a Full-Sized or Third-Mirror Break-off InstantVolume Snapshot: CLI

The vxsnap prepare command enables FastResync, creates a DCO andredundant DCO volume. and associates the DCO with the volume. After you runvxsnapprepare. you create the storage container for the snapshot as follows:

You can use vxsnapaddmir to add a new snapshot mirror to the volume.

if there is a sufficient number of suitable plexes available in the volume. youcan break off and use an existing ACTIVE plcx from the volume.

You can create a new, empty volume to be used as the snapshot volume, Thisvolume must be the same size as the volume for which the snapshot is beingcreated. and it must also have the same region size.

a Find the required size for the snapshot volume:

LEN='vxprint -g diskgroup -F%len volume name'

b Find the name of the DCO:

DCONAME='vxprint -g diskgroup -F%dco_namevolume name'

c Use vxprint on the DCO to discover its region size (in blocks):

RSZ='vxprint -g diskgroup -F%regionsz $DCONAME'

d Create a volume of the required size and redundancy

vxassist -g diskgroup make snap_vol $LEN

e To prepare the volume for instant snapshot operations. enable FastResync:

vxsnap -g diskgroup prepare snap_volregionsize=$RSZ

-------------------------- --------Lesson 7 Point-in-Time Copies 7-19

Copyright T 200{) Syrnanter. Corporauoo All rights reserved.

Creating and Managing Full-Sized or Third-Mirror Break-offInstant Volume Snapshots: CLI

Create the snapshot volume using one of these methods:

Break off an existing plex to create the new snapshot:vxsnap -9 diskgroup makesource=orig_ vol/newvol=snap_ ,/ol/plex=plex_name

Break off the mirror added by the vxsnap addmir command:vxsnap -g diskgl-OUp makeaour-cee or- 19_ vol/newvol=snap_ vo.l ynmt r r-or-e numoe z-

Specify an existing empty volume to be used as the snapshot:vxsnap -g d.iskgroup makesource=or19_ vol/snapvol=snap_ voI

Update:vxsnap -gvxsnap -gvxsnap -gvxsnap -g

diskgrotI[! refresh snap_vol source= or19_ voldiskgroup reattach snap_vol source= ori9_ voldiskgroup restore oriy_ vo.I source= snap_voldiskgroup dis snap_vol

Creating a Full-Sized or Third-Mirror Break-off Instant Snapshot: CLI

To create a new snapshot volume by breaking 01'1'an existing plcx in the originalvolume, you use the vxsnap make command. specify the name of the newsnapshot volume, and include the name of the plcx to be used. This attribute canonly be used with plcxcs that are in the ACTIVE state.

To create a new snapshot volume using the minors added by the vxsnapaddmir command. youusc the vxsnap make command. specify the name ofthe new snapshot volume and include the number ofplcxcs that have been addedby the vxsnap addmir command and that arc in SNAPDONE state.

To use an existing. empty volume as the snapshot volume. you use the vxsnapmake command and specify the names of the source volume and the snapshotvolume. Prior to running this command. you must create an empty volume with therequired degree of redundancy, and with the same size and same region size as theoriginal volume.

Remove:vxedit -9 diskgroup -r rm snap_vol

Updating a Full-Sized or Third-Mirror Break-off Instant Snapshot: ell

You can manage full-sized instant snapshots using the following commands:

To refresh a snapshot volume: vxsnap refresh

To reattach a snapshot volume: vxsnap reattach

To restore a volume from a snapshot: vxsnap restore

To disassociate a snapshot volume: vxsnap dis

To split a snapshot volume: vxsnap spli t

See the vxsnap (1m) manual page for more information.

7-20Copynght ~.2006 Svmaruec Corporation All nqnts reserveo


Removing a Full-Sized or Third-Mirror Break-off Instant Snapshot: ell

A dissociated instant snapshot can be deleted altogether using vxedi t:

vxedit -g diskgroup -r rm snap_vol

Sample of DCO and Del

The following is an example of a DCa and DC L:vxprint -htg datadgl

DG NAME NCONFIG NLOG MINORS GROUP-IDST NAME STATE DM_CNT SPARE CNT APPVOL_CNTOM NAME DEVICE TYPE PRIVLEN PUBLEN STATERV NAME RLlNK_CNT KSTATE STATE PRIMARY DATAVOLS SRLRL NAME RVG KSTATE STATE REM_HOST REM_DG REM_RLNKCO NAME CACHEVOL KSTATE STATEVT NAME NVOLUME KSTATE STATEV NAME RVGNSET/CO KSTATE STATE LENGTH READPOL PREFPLEX UTYPEPL NAME VOLUME KSTATE STATE LENGTH LAYOUT NCOLIWID MODESO NAME PLEX DISK DISKOFFS LENGTH [COUjOFF DEVICE MODESV NAME PLEX VOLNAME NVOLLAYR LENGTH [COUjOFF AM/NM MODESC NAME PLEX CACHE DISKOFFS LENGTH [COUjOFF DEVICE MODEDC NAME PARENTVOL LOGVOLSP NAME SNAPVOL DCO

dg datadgl defaull defaull 31000 1117567000.33.lrainl

dm datadq 100 e1t2dOs2 auto 2048 10404096 -dm datadg 10 1 e1t2dls2 auto 2048 10404096 -dm datadq 102 e1t2d2s2 auto 2048 10404096 -dm datadg 103 e1t2d3s2 auto 2048 10404096 -dm datadg 104 e1t2d4s2 auto 2048 10404096 -dm datadgl05 e1t2d5s2 auto 2048 10404096 -

v datavoll ENABLED ACTIVEpi dalavoll-0l datavoll ENABLED ACTIVEsd datadgl00-0l dalavoll-0l datadgl00 0de datavoll_deo datavol 1 datavoll delv datavoll_del ENABLE-D ACTIVE 544pi datavoll_del-Ol datavoll_del ENABLED ACTIVE 544sd datadgl0l-0l datavoll_del-Ol datadgl0l 0 544

204800 SELECT204800 CONCAT204800 0

fsgenRW

e1t2dO ENA

SELECTCONCATo

genRW

c1t2dl ENA

7-21lesson 7 Point-in-Time Copies

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Creating and Managing Full-Sized or Third-Mirror Break-offInstant Volume Snapshots; VEA

Create:

I

r Cr.::I~:~~~:;:;lnstant sn~psho.t-=~~~e'I:-:e-~-e-af-Y-"'-r-ror-ob-je-ct-s-----'

, r. Specfye,lsting vokme for snapshot f,lJII,~e,g1 Available ,,;rrors

Volume. ISP-OP_ld::OJ Break0 JJorfqvol-Ot (dat,3dgOl )

JJ011';1\/01-02(datadg02 )

Update:SelectActions->InstantSnapshot->Refresh.SelectActions->InstantSnapshot->Reattach.SelectActions->InstantSnapshot->Restore.SelectActions->InstantSnapshot->Dissociate.Remove:SelectActions->DeleteVolume.

Creating a Full-Sized or Third-Mirror Break-off Instant VolumeSnapshot: VEA,--------------------,----------------------------------------

Select: lhe volume tor which you want a snapshot

luput:

Actions ->Instant Snapshot=c-Crcate

~ J_ ~

Snapshut type: Select Full sized or Break off

Options fur the snapshot: Specify the volume to use.You call create a new volume or select all existingvolume. Select Syncing if you want the contents of theinstant snapshot to be hilly synchronized with thecontents of the orig inal volume at the point when thesnapshot is taken.

Disks for this snapshot: Allow \'xVM to determine(dctuuln. or manually select disks to use fix the snapshot.

\ u lume auributes: Specify a volume name. the size ofthe volume. the type of volume layout. and other layoutcharacteristics. Assign a meaningful name to the volumethat describes the data stored in the volume,

File system: Create a file system on the volume anti settile system options,


Cupynynt 2006 5\'I!"II1(I<(; Co-porauon All rights reserved

To create a space-optimized instant snapshot and create a new cache object at thesame time, you specify the size of the cache object in the command.

The cache object is created with a default name that you can view with vxprint.

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Creating and Managing Space-Optimized Instant Snapshots:ell

Create a snapshot and cache object at the same time:vxsnap -g diskgroup makesource=orig_ vol/newvol=snap_ vol/ cache sLzeesi ze

Remember to prepare the volume In advance.Example:vxsnap -g datadg make \source=datavol/newvol=snap-datavol/cachesize=lg

Update:vxsnap -g diskgroup refresh snap_ vol source=orig_ vol.

orvxsnap -g diskgroup restore olig_ 1.'0.1. source=snap

-vol

Remove the snapshot and then stop and remove the cache object:vxedit -g diskgroup -rf rm snap_ voL

vxcache -g diskgroup stop cache_object

vxedit -g diskgroup -r rm cache_object

Creating a Space-Optimized Instant Snapshot: CLI

Updating a Space-Optimized Instant Snapshot: CLI

You can refresh a space-optimized instant snapshot or restore a volume from asnapshot.

Removing a Space-Optimized Instant Snapshot: CLI

To permanently delete the snapshot and release the storage resources, you use thevxedi t command to remove both the snapshot volume and the cache object.

Find the names of the top-level snapshot volumes that use the cache object:

vxcache listvol cache_object2 Remove the top-level snapshots and their dependent snapshots:

vxedit -g diskgroup -rf rm snap_vol.,.3 Stop the cache object:

vxcache -g diskgroup stop cache_object4 Remove the cache object and its cache volume:

vxedit -g diskgroup -r rm cache_object


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Creating a Shared Cache ObjectIf you want to set up a cache object to be used by multiplespace-optimized instant snapshots in a disk group, you cancreate the shared cache object before creating any snapshots:

1. Create the volume to be used for the cache volume.vxassist -g datadg make cachevol 19 \layout=mirror datadg16 datadg17

2. Create a cache object on top of the cache volume.vxmake -g datadg cache cobjdatadg \cachevolname=cachevol autogrow=on

3. Enable the cache object.vxcache -g datadg start cobjdatadg

4. Create a space-optimized snapshot associated with thecache object.vxsnap -g datadg make \source=datavol/newvol=snapvol/cache=cobjdatadg

Creating a Shared Cache Object Before Creating a Snapshot

ltyou nccd to create several space-optimized instant snapshots for the volumes ina disk group. you Illay find it more convenient to create a single shared cacheobject in the disk group rather than a separate cuche object for each snapshot.

Decide on the following characteristics that you want to allocate to the cachevolume that underlies the cache object:

The size ofthe cache volume should be sufficient to record changes to theparent volumes during thc interval between snapshot refreshes. Arecommended value is I() percent of the total size otthc parent volumes Ill!' arefresh interval 01" 24 hours.

lfrcdundancy is a desired characteristic of the cache volume, the cache volumeshould be mirrored. This increases the space that is required for the cachevolume in proportion to the number 01" mirrors that the cache volume has.

If the cache volume is mirrored, space is required on at least as many disks as ithas mirrors. These disks should not be shared with the disk> used tor the parentvolumes. The disks should also be chosen to avoid impacting I/O performancefor critical volumes, or hindering disk group split and join operations.

7-24 VERITAS Storage Foundation 5.0 (or UNIX: Maintenance

Copyfi\.jrll LiJD6 SyllldlitHC Corporauo« /'III nqrus re<'/lrved

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Creating and Managing Space-Optimized Volume Snapshots:VEA

Create:Select Actions->Instant Snapshot->Create.

Select Sp'acJl-QP1lm~~c!.. _r. ~!~.~ja_~·~:¥'j:le~06je.:~

Update:

Select Actions->Instant Snapshot->Refresh.

Select Actions->Instant Snapshot->Restore.

Remove:

Select Actions->Delete Volume.

Creating a Space-Optimized Instant Snapshot: VEA

Navigation path: Act ions->I nstant Snapshot->( 'rcatc

Select: The volume for which you want a snapshot

Input: Disks for FastResync: Allow VxVM to determine(default I. or manually select disks to use.

Enable Fastltesync: Specify the number of DCa minorsand the region size.

Suapshot type: Select Space optimized.

Create a new cache object: Select if you wam to create aOC\\' cache.

Choose an existing cache ubject: Select if you havealready created a cache.

Disks for this snapshot: Allow VxVM to determine(dcfaulr). or manually select disks to use.

Updating a Space-Optimized Instant Snapshot: VEA

Refresh: Refreshing an instant snapshot replaces it with another point-in-timecopy of a parent volume.

Restore: For an instant space-optimized snapshot. the cached data is used torestore the contents of the specified volume. The snapshot itself remainsunchanged by the operation.

Lesson 7 Point-in- Time Copies 7-25Copynqht ~. :!t106 Symantec Corporation All nqhts reserveo

Displaying Instant Volume Snapshot Information: ellTo display information about instant snapshots:vxsnap -g diskgroup print [orig_ vOl;-:l'--__ --.For example:vxsnap -g datadg printNAME SNAPOBJECT TYPEdatavol volume

full_ls_snp volumesp-op_la_snp volume

datavo12 - - volumesp-op_2a_snp volumesp-op_4b_snp volumefull_2a_snp volume

full 1a datavol_snp volumesp-op_la datavol_snpl volumesp-op 2a datavo12 snp volumesp-op_2b datavo12 __snpl volumefull 2a datavo12_snp2 volume

PARENT SNAPSHOT%DIRTY %VALID100.00

full la 0.00sp-op_la 0.00

100.00sp-op_2a 0.00sp-op_2b 0.00full 2a 0.00

datavol 0.00 100.00datavol 0.00 0.00datavo12 0.00 0.00datavo12 0.00 0.00datavo12 0.00 0.00

I Snapshot volumes I

Displaying Instant Volume Snapshot Information

Use vxsnap print to display information about volumes and their associatedinstant snapshots.

The 'YoDIRTY value is based on what has been written to the volume. The value isthe percentage of the snapshot plcx or detached plcx that is dirty with respect to theoriginal volume.

If an instant snapshot volume has not been synchronized with the original volume.the ~;'VALID value is tile same as the "("DIRTY value. If the snapshot were partlysynchronized. the '~"VALID value would lie between the %DIRTY value and100"'0. If the snapshot \\ ere fully synchronized. the "~.vALI D value would be100%. The snapshot could then be made independent or moved into another diskgroup.

Note: You can also use the vxsnap -9 diskgroup -v list command todisplay snapshot iutonnution tor a disk group.

Copynqtuc 2006 Syrn.mtec Co-ooranon All nqtus reserved


'~)~lant~c

Using Volume Snapshots for Off-Host Processing

oSplit snapshots into a~ separate disk group.

f2\ Import on another~ host for processing.

ohpdg

~Iill

CD Reimport, rejoin, and resynchronize.

Using Volume Snapshots for Off-Host ProcessingThis section provides an outline of how to apply off-host processing by combiningthe full-sized or third-mirror break-off instant snapshot. disk group split and join,and FastResync features ufVxVM. You can use this outline to setup a regularbackup cycle or to set up a replica of a production database for decision supportpurposes.

Off-Host Processing Phases

Implementing off-host processing has three general phases:

Phase I: Create, Split, and DeportOn the primary host, create a snapshot volume. split it into a separate diskgroup, and deport the disk group.

Phase2: Import, Process,and DeportOn another host, import the disk group containing the snapshot volume andperform off-host processing. When you have completed your off-hostprocessing tasks. deport the disk group.

Phase3: Import, Join, and ResynchronizeOn the primary host, bring the snapshot volume back by rejoining the diskgroups and rcsynchronizing the volumes.

Lesson 7 Point-in-Time Copies 7-27Ccpynqht £: ;!OO(i Symantec Corporanon All nglll~ r\'!servIilo

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Phase I: Create, Split, and Deport

In this procedure, the primary host contains the datadg disk group and thedatavol volume. Till: snapshot volume of datavol is called snapvol. Thedisk group that is moved to another host is called offhostdg.

On the primary host. enable Fastkcsync for the datavol volume.2 On the primary host, add an additional mirror or create an empty volume lor

use as the snapshot volume. The example 011 the slide shows adding anadditionul mirror to be used lor the snapshot operation. Note that ill this caseyuu have to wait until the synchronization is complete and the additional plcxis in SNAPDONE state before you can create the snapshot.

3 On the primary host, itthe original volume contains database tables in a filesystem, suspend updates to the volume. The database may have a hot-backupmode that enables you to do this by temporarily suspending writes to its tables.If yo II arc selling up a replica ota production database, prepare the off-hostprocessing host to receive the snapshot volume. This preparation may involveselling lip private volumes to contain redo logs and configuring files that arcused to iniiiulizc the database.

4 On the primary host. create a full-sized or third-mirror break-off instantsnapshot Ior the volume,

5 I I' you temporarily suspended updates to the volume by a database, you cannow release all of the tables Irom hot-backup mode.

6 Spl it the snapshot volume into a separatedisk group by lIsing vxdg spl i t. Afull-sll.ed instant snapshot must be tully synchronized before splitting.

7 Deport the disk group that contains the snapshot volume,

OHP Example: Phase 11. Enable FastResync on the volume:

vxsnap -g datadg prepare datavol2. Add an additional mirror for use as the snapshot volume:

vxsnap -g datadg addmir datavol3. Suspend updates to the volume and unmount the file

system:umount /mntl

4. Create a full-sized instant snapshot for the volume:vxsnap -g datadg make \source=datavol/newvol=snap-datavol/nmirror=l

5. If you temporarily suspended updates to the volume by adatabase, release the tables from hot-backup mode.

6, Split the snapshot volume into a separate disk group:vxdg split datadg offhostdg snap-datavol

7, Deport the disk group:vxdg deport offhostdg


Cupyrlght 2r)nf) Svroa-uec Ccrporancu All flgtll~reserved

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OHP Example: Phase 2

8. On the off-host processing host, import the disk group:vxdg import offhostdgvxvol -g offhostdg start snap-datavol

9. To perform off-host processing, mount the snapshotvolume:mount -F vxfs \/dev/vx/dsk/offhostdg/snap-datavol /rontl

10. When processing is complete, unmount the snapshot:umount /rontl

11. Deport the disk group:vxdg deport offhostdg

symantec.

Phase2: lrnport, Process,and Deport8 On the off-host processing (0111') host where the backup or processing is to be

performed. import the disk group that contains the snapshot volume,

9 To perform off-host processing. you must first mount the snapshot volume. Forexample:

mount -F vxfs /dev/vx/dsk/offhostdg/snap-datavol \/mntlNote: On Linux. use mount - t .

In the syntax, /mnt 1 is tile mount point for tile file system,

Then. you can perform the off-host processing activities:

If you are performing online backup. then back up the file system usingyour backup utilities and methods,

I f you are performing decision support, then issue the appropriate databasecommands to recover and start the replica database tor its decision-supportrole,

10 When you are ready to reattach the snapshot plcx with the original volume,unmount the snapshot volume,

11 On the 0111' host, deport the disk group that contains the snapshot volume,

lesson 7 Point-in-Time Copies

Copvnqnt:" 2006 Symaote- Ccrporaucn /1.11ncnts reserv •.. t

7-29

OHP Example: Phase 3

12. On the primary host, reimport the disk group:vxdg import offhostdg

13. Rejoin the disk group with the original disk group:vxdg join offhostdg datadg

14. Restart the snapshot volume:vxrecover -g datadg -m snap-datavol

15. Refresh the snapshot volume with the original volume:vxsnap -g datadg refresh snap-datavol \source=datavol

Phase 3: Import. Join, and Resynchronlze

12 On the primary host. rcimport the disk group that contains the snapshotvolume.

13 Rejoin the disk group that contains the snapshot volume with the disk groupthat contains the original \'olumc by using vxdg join.

14 The snapshot \ olumc is Initially disabled following the join. 011 the primaryhost. restart the snapshot volume.

15 Un the primary host. refresh the plcxcs of the snapshot volume with theoriginal volume.


,tL,'. . symantcc$illft?s #k. ,

Creating and Managing Storage Checkpoints: CLI

Create:fsckptadm [-nruvl create ckpt_llame moullt_poilltfsckptadm -v create thu_7pm /checkptl

Mount:

mount -F vxfs -0 ckpt=ckpt_llame/dev/vx/dsk/d"skgroup/volume_llamp:ckpt Ilame/mount_point

mount -F vxfs -0 ckpt=thu7pm \/dev/vx/dsk/datadg/voll:thu_7pm /checkpt2

Unmount:

By mount point:umount /checkpt2

By pseudo device name:umount /dev/vx/dsk/datadg/voll:thu 7pm

Creating and Managing Storage Checkpoints

Creating a Storage Checkpoint: CLI

To create a storage checkpoint, you use the f sckptadm create command:

-n sets the nodata attribute, creating a checkpoint that contains no tile data,

- r sets the remove attribute on a checkpoint at creation time. This ensuresthat the checkpoint is automatically deleted under certain conditions,

-u sets the nomount attribute ofa checkpoint when it is created, making thecheckpoint not mountable.

-v specifies verbose mode, which displays extensive statistical information.

Mounting a Storage Checkpoint: CLI

To access a storage checkpoint, you mount the checkpoint using the mount option:

-0 c~pt=ckpt_name

Storage checkpoints are mounted as read-only storage checkpoints by default.If you need to write to a storage checkpoint, mount it using the -0 r w oprion.

Ifa storage checkpoint is originally mounted as a read-only storagecheckpoint, you can remount it as writable using the -0 remount option.

To mount a checkpoint of a file system, tirst mount the file system itself

To unmount a file system, first unmounr all of its storage checkpoints,

Ccoyr.unt f, 2006 Symantec Corporauon All n~hls reserverl

7-31Lesson 7 Point-in- Time Copies

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Creating and Managing Storage Checkpoints: VEACreate:

Select Actions->Storage Checkpoint->Create.Mount:Select Actions->Storage Checkpoint->Mount.

F~esvseen: ImntCN:c~r.ame: ~12:::-7_-:-"-::.0""'_"70-::.,,,,,,,,----1

He Sy~em, Jrrn.

""dl""r--~

Enable Quotas:Select Actions->Storage Checkpoint->Enable Checkpoint Quotas.

Remove:Select Actions->Storage Checkpoint->Remove.

:;;P.erroo.,.~

;; ~ci;iti

Mo\rJt pont: !(\I:,dDt/m,..,t/'::7 _1603_0401'::7

Select:

Creating a Storage Checkpoint: VEA

The Ilk system tor which you wall! to create a checkpoint

Navigution path: Actions ->SlOrage Checkpoint- ··>Create

Input: Checkpoint name: Specify a checkpoint name.Removable: The default is for a removable checkpoint.1\I0Ullt: Mark the check box if you want the checkpointmounted and supply a mount point.

Select:

Mounting a Storage Checkpoint: VEA

The tile system for whi, h you want to mount a checkpoint

:\a\igatioll path: Actions >Storage Checkpoint =Mount

Input: Checkpoint name: Specify a checkpoint name. or use thedctaulr provided.l\IuulIl point: Verify the mount point that is displayed.Mount details: Set mount options. such as read-only.


symantec.

Displaying Storage Checkpoint Information

To list all checkpoints in a file system, you use the command:

fsckptadm [-clvl list mount_point .•.- c resets statistic counters. such as the number of reads, writes, and pushes.

-1 displays statistical information on the file system. in addition to itscheckpoints.

-v specifics verbose mode, which displays extensive statistical information.

To display the name of a storage checkpoint containing the tile at a specified path.you use the pathinfo keyword:

fsckptadm [-cvl pathinfo path_name

':''Rff~

Displaying Storage Checkpoint InformationTo display information about storage checkpoints:fsckptadm [-clvl list mount_point

To list all checkpoints on the ImntO file system:fsckptadm list IrontOImntOfri_7pm:

ctime Fri 04 Feb 2005 07:14:39 PM PSTmtime = Fri 04 Feb 2005 07:14:39 PM PSTflags = nodata

fri_6pm:

ctimemtimeflags

Fri 04 Feb 2005 07:02:17 PM PSTFri 04 Feb 2005 07:02:17 PM PSTlargefiles. removable. mounted


Copyright (1;": 2006 Symanter Corporation All nqtus reserved

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Using Storage Checkpoints: Restoring a File SystemUnmount the file system, and then use:

fsckpt restore [-11 device nameThis command runs an interactive utility where you select the checkpointto which to roll back.

r

---·_· .The filesets listed before therestoration show an UNNAMEDrootfilese! and five storage checkpoints.

fsckpt_restore -1

c c c

'~K K K K K

P PT T T T T5 4 3 2 1

11am 10am 9am 8am

cKP

T T2 1

8am 7am

This examplerestored from

After running the command and selectingCKPT 3 , the former UNNAMED root filesetand CKPTSand CKPT4 were removed;CKPT3 is now the primary fileset.

Restoring a File System from a Checkpoint

Mountable data storage checkpoints on a consistent and undamaged file systemcan he used by backup and restore applications tu restore either individual files oran entire Ii lc system. Resturatiun from storage checkpoints can also help recoverincorrectly modified files, but storage checkpoint restoration typically cannotrecover Irom hardware damage or other file system integrity problems.

Restore files by copying the entire lilc from a mounted storage checkpoint hack tothe primary lilesct. To restore an entire file system, you can designate a mountabledata storage checkpoint as the primary Iilcsct using the f sckpt _restorecommand. When a file system is restored lrom a storage checkpoint using thefsckpt restore command . .I11changes made to that Ide system after thatstorage checkpoint's creation date are permanently lost. The only storagecheckpoints and data preserved arc those that were created at the same time, orbefore. the selected storage checkpoint's creation.

Aller unmouruing the file systems. use the fsckpt_restore command torestore a file system from a storage checkpoint:

fsckpt restore [-11 device name [ckpt name]

In the syntax:

device_name Specifics the block device on which the file system resides

ckpt name Specifics the name of the storage checkpoint lrom \I filch torestore the file system

-1 Lists information on the file system root and all or its storage checkpoints


Copvnqnt c 2006 Svmaruec Corporauon All nctu-, r~sHrverl

Example File System Restoration from a Storage Checkpoint

The following example restores a file system from the CKPT3 storage checkpoint.The filcscrs listed before the restoration show an unnamed root fileser and sixstorage checkpoints.

Run the f sckpt restore command

fsckpt restore -1 /dev/vx/dsk/datadg/vo12

UNNAt~ED:ctime Fri 04 Feb 2005 06:28:24 PM PSTmtime Fri 04 Feb 2005 06:28:26 PM PSTflags file system root

CKPT6:ctime Fri 04 Feb 2005 06::18 :35 Pt~ PSTmtime Fri 04 Feb 2005 U6:28 :35 PM PSTflags removable

CKPT5 :ctime Fri 04 Feb 2005 06:28:34 PM PSTmtime Pri 04 Peb 2005 06:28:34 PM PSTflags nomount

CKPT4:ctime Fri 04 Feb 2005 06:28:33 PM PSTmtime Fri 04 Feb 2005 06:28:33 PM PSTflags removable

CKPT3:ctime Fr-i 04 Feb 2005 06 :28 :31 PM PSTmtime Fri 04 Feb 2005 06 :28 :36 PM PSTflags removable

CKPT2:ctime Fri 04 Feb 2005 06 :28 :30 PM PSTmtime Fci 04 Feb 2005 06 :28 :30 PM PSTflags none

CKPT1 :ctime Fri 04 Feb 2005 06:28: 29 PM PSTmtime Fri 04 Feb 2005 0":28 :29 PM PSTflags nodata

ctimemtimeflags

Fri 04 Feb 2005 06:28:31 PM PSTFri 04 Feb 2005 06:28:36 PM PSTremovabJe

2 In this example, select the CKPT3 storage checkpoint as the new root filesct:

Select checkpoint for restore operatIon or enter <Return> to listcheckpoints: CKPT3CKPT3:

WARNING!! Checkpoint CKPT3 has been modified.WARNINGl J Any file system changes or checkpojnts made afte!::"Fri 04 Feb 2005 06:28:31 PM PST will be lost.

Lesson 7 Point-in-Time Copies 7-35Copynght (0l2006 Symanter Coeoorar.on 1\11fights resllfverj

3 Enter y tu restore the Ilk system trom CKPT3:

Restore the file system from checkpoint CKPT3 ? (ynq) y(Yes)File system restored frol11 CKPTJ

If the tilcscts arc listed at this point, the list shows that thc former UNNAMEDroot filcsct and CY.PT6. CKPT5, and CKPT4 were removed, and that CKPT3 isnow the primary filcsct. CKPT3 is now the lilcset that will be mounted bydefault.

4 Run the f sckpt rest ore command

fsckpt restore -1 /dev/vx/dsk/datadg/vo12

CKPT3:ctime Fri 04 Feb 2005 06 :28 : 31 PM PSTmtime Fri 04 Feb 2005 06 :28 :36 P~l PSTflags tile system roor

CKPT2:ctime Fri 04 Feb 2005 06:28: 30 PM PSTmtime Fri 04 Feb 2005 06:28 :30 PM PSTflags nODe

CKPT1:ccime Fri 04 Feu 2005 C!6:28:29 P~l PSTmtirne Fri 04 Fet 2005 06 :28:29 PM PSTflaqs nodata

VERITAS Storage Foundation 5.0 for UNIX: Maintenance7-36Copyngnl '_J 2006 Svmantec Corpor anon 1\11""ll't'> -oservec

syrnantec.

Lesson Summary

• Key PointsIn this lesson, you learned how to create andmanage traditional and full-sized instant volumesnapshots, space-optimized instant volumesnapshots, and storage checkpoints. This lessonalso covered off-host processing and backup andrecovery of file systems.

• Reference Materials- VERITAS Volume Manager Administrator's Guide-VERITAS File System Administrator's Guide- VERITAS FlashSnap Point-In-Time Copy Solutions

Administrator's Guide

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Appendix J\ provides complete lab instructions. '-I.<lh -i· I'oim-in-Tinu- (·opics"·p;I~C :\-(l."i

Lab 7Lab 7: Point-in-Time CopiesIn this lab, you perform off-host processing using full-sized instant volume snapshots, create space-optimized instant volume snapshots, and restore a filesystem using storage checkpoints.

[Jor Lab Exercises, see Appendix A.For Lab Solutions, see Appendix B.

Appendix B provides complete lab instructions and solutions .:' , Iii) 7 <;"llIlll'I1S

PUIl1I-iIl- Illlle (l'plc'S. P:I!"C II-'n

------_.----------------Lesson 7 Point-in-Time Copies

Copyright c:.2006 Symanl~r Corporation All nqnts reservea

7-37

Lesson 8

Other Enterprise Features Overview

Lesson Introduction• Lesson 1: Maintaining Data


the VxVM Architecture• Lesson 3: Encapsulation and

Rootability• Lesson 4: Troubleshooting the Boot

Process• Lesson 5: Volume Maintenance• Lesson 6: Performance Monitoring• Lesson 7: Point-in-Time Copies

~1~~~~fe~~ther~~~erprise Fea~ures~

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symantec


Topic After completing this lesson, you willbe able to:

What Is Dynamic Storage Describe the purpose and benefits of~T~i:.:e.:..:ri.:..:ng~?~,----------1 dynamic storage tiering (D..;S:..:T.!.'-), -IWhat Is Intelligent Storage Describe the purpose and benefits ofProvisioning? intelligent storage provisioning (ISP),

What Is the Storage Describe the purpose and benefits of theFoundation Management Storage Foundation Management ServerServer? (SFMS),

8-2COPYflQili '; 200t, Svmautec Corporatrou All IH.jhts reserved

VERITAS Storage Foundation 5,0 for UNIX: Maintenance

The High Cost of Data Life-Cycle ManagementCompanies are implementing alternate solutions toreduce the cost of storage, including:• Centralizing data storage into large data centers• Establishing service-level-agreements (SLAs) with the

departments that use the storage, or storage accounts

Survivability When my application is reachingcurrent does it need to be? of Data its storage capacity, how quickly

~

. ! do I need fresh capacity online?

Time to ~ Time toecover ~ Capacity

,-------------L,What level of downtimecan this application or Application What level of storagestorage account tolerate? Performance perf~rm~nce does my

application need?

Dynamic Storage Tiering is the technology that helps keep storagecosts under control while effectively meeting business needs.

What Is Dynamic Storage Tiering?

The High Cost of Data Life-Cycle Management

Data life-cycle management is the process of:

Managing data from its creation to its deletion or archiving

Moving data through an organization based on business rules and policies

In the past, organizations often solved their data life-cycle management storageproblems by buying more disks, which was an expedient method of addressingstorage management. However, this method created numerous problems. not theleast of which was under utilization.

Storage virtualization combined with storage networking architectures has led tonew approaches in storage management that are highly centralized. Thiscentralized approach to managing storage enables data centers to better handleincreased amounts of storage and increasingly complex environments.

Today. data centers can match the underlying storage technology to the applicationrequirements of thc storage accounts through a service-level agreement (SLA)using dynamic storage tiering.

Data centers set up policies for serving departments within the organization tomeet their storage provisioning needs. Each department's distinct applicationsare treated as storage accounts.

Each storage account is serviced with storage that meets their business needs.Business-critical systems that need the greatest levels of availability andperformance receive the highest levels of storage service, while less-criticalsystems receive predefined and agreed-upon levels of storage service.

Lesson 8 Other Enterprise Features Overview

Copyright (f, 2n06 Svmantec Corporation A.II nqhts reservpd

8-3

What Is Dynamic Storage Tiering (DST)?DST enables administrators to manage the placementof files by defining placement policies that control bothinitial file location and the circumstances under whichexisting files are relocated. Examples:

Move to tier 2 all filesPolicy-based storagetiering (placementpolicies)Dynamic movement offiles without interruptionto applicationsApplication transparencyDatabase support

/ filesystem

Tier 1 I Gold I

that have not beenaccessed in 90 days.Place payingcustomers on tier 1and non-paying on tier2; if either change,they are dynamicallymigrated to new tier ofstorage.Roll sales informationfrom previousquarters onto tier 2storage.

Tier 2

Defining Dynamic Storage Tiering (DST)

The DST allocation and relocation policies can be used to manage the data of thestorage accounts throughout the data life cycle. The policy-based rules can, withminimal or no intervention, ensure that business-critical applications havesufficient storage space to achicv c uninterrupted service 24 hours per day, sevendays per \\ cck , and ensure thai business requirements arc met.

Dynamic Storage Tiering is the next level of tiered storage, mapping theinformation within an appl icaiion to storage tiers.

Dynamic Storage Tiering is real-rime mapping of data that is policy driven. Youdefine the policies based on:

File type

Directory type

End-user

Frequency of Ii lc access

DST enables you to move files from one volume to another with no impact onapplication or dutabasc architecture.

DST file allocation and relocation help you to:

More efficiently use your storage resources without disrupting users orapplications.Place files on different classes or devices-s-lur example. inexpensive orexpensive devices. or lust or slow devices.Bcucr manage your ever-changing environment.

VERITAS Storage Foundation 5.0 for UNIX' Maintenance8-4

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Examples of DST Levels NOTE: Numbers used in the tables are forexample purposes only, to show the relative

Example A cost savings of different storage layouts.

Factors Storage Account A Storage Account B

Redundancy Two full copies Three full copies

Time to Capacity Two hours Two minutes

Time to Recovery Two hours Two minutes

Performance Medium (Tier 2) Fast (Tier 1)

Cost per GB of storage SSG I GB SlO() i G8

Example B A storage account requests two full copies of all their data.To reduce the cost, they separate the less important data onto RAIO-5.

R_~, Cest perOS •••••••~ S_.T.taICM•• IMethod size (GB ) Storage

Mirror $100 1,000 2,000 $;'1)0,000

IMirror (Tier 1) $100 200 ! 1400 [

IRAIO-5 (Tier 2) $50 600 ! 11,000 : $90.()OO

DST Cost Savings

Data centers can use a charge-back 1110delwith DST. For example. an c-commerccapplication that generates a significant portion of the company's revenue may needto have very fast application time to recovery, The finance department may want toensure that availability of its data can survive catastrophic site failures. requiringthe copies of data to be stored at a remote disaster recovery site.

As higher levels of DST are deployed for storage accounts, the costs associatedwith providing those services also increase. Important elements in the managementof these storage accounts arc clearly defined accountability and methodologies tomanage security of stored data and measurement of total cost of ownership forstorage in each account.

The data center works with each storage account to determine the most appropriatelevel of service based on redundancy, performance. and cost needs.

As the first table on the slide shows, if the storage account needs higher levels ofservice, they pay more fur it.

In the second table on the slide, the storage account pays S200.000to fully mirrorall of their data. However, if they use R!\ID-5 for part of their data instead. theypay unly S90.000.

Lesson 6 Other Enterprise Features Overview 8-5Copvnqnt 200b Symantec cooo-auon All rights reserveo

syrnantec

DST Components

The data center can implement DST policies to easily andappropriately move the data throughout the organizationas the data continues on its life cycle.

Frequently accessed fileson fastest volume (striped)

Allocation policiesinitially allocatevarious types ofincoming data tospecific locations.

After time. relocationpolicies move filesbased on policiesyou set up.

I Infrequently accessed files onI slower volume (concatenated)

~Metadata on most redundantvolume (triple mirror)

What Makes OST Possible?

VERITAS Storage Foundation combines several technologies to enable allocationand relocation.

VxV,,", Volume Sets

A volume set enables multiple volumes to be combined together under one filesystem. The volume set feature works in conjunction with the multivolume filesystems.

volume sets allow file systems to make the best use of the different performanceand availability characteristics or the underlying volumes, For example, filesystem mctadata can be stored on v olumcs with higher redundancy, and user datacan he stored on volumes with better performance.

VxFS Multivolume File Systems

VERITAS File System provides support for multivolume file systems (MVFS)when used in conjunction with VxVM. Through multidcvicc support, a single Iilcsystem can be created over multiple volumes, while each volume has its ownproperties. The incoming data can he isolated and sent to any volume within thevolume set. For example, you can place mctadaia on mirrored storage and placefile data on a bcucr-pcrforming volume type. such as striped.

File systems can also reside on different classes of devices, so that a file systemcan be supported from both inexpensive disks and /i'0111 expensive arrays.

All 110 to and from an underlying volume is directed through the volume set. Afile's location in the directory tree docs not need to determine the volume on whichit is stored.


Potential uses of multivolume support include:

Controlling where tiles arc stored so that specitic files or file hierarchies can beassigned to different volumesPlacing the VxFS intent log 011 its own volume to minimize disk headmovement and increase performanceSeparating storage checkpoints so that data allocated to a storage checkpoint isisolated from the rest of the file systemSeparating mctadata fi'OI11 file dataEncapsulating volumes so that a volume is displayed in the tile system as a tile,This is particularly useful for databases that are running on raw volumes.

Allocation Policies

VERITAS File System provides a method to define and assign allocation policies.These policies send data that is entering the file system to specific devices.Allocation policies specify a list of volumes and the order in which to attemptallocations.

Relocation Policies

VERITAS File System provides a method to define relocation policies that movedata based on criteria that you set up.

Lesson 8 Other Enterprise Features Overview 8-7Copvr.qtu <f, 2()06 Symauter. Corpornnon All not-ts reserved

"C"'::A!~~I. ···--'-sYmantec.

Why Use OST: Separate by Type of FileProblem: Storage checkpoints are stored in thesame space that is available to the primary file system.

Solution: With DST, storage checkpoints can be isolatedand sent to a separate volume from the file system.

Why Use CST?

Example I

The system administrators in the QA department want to do some testing using thedata from storage checkpoints. However. they would prefer to conduct the testingon a separate host.

They an: looking for a way to separate storage checkpoints so that data allocated toa storage checkpoint is isolated from the rest of the file system.

Challenge:

The system administrator wants an easy way to place the storage checkpoint dataon a device that is separate from the device that stores the Ii lc system data.

Solution:

Using l)ST. you can send all the storage checkpoints to a separate volume from theprimary file system.

Storage checkpoints can reside on one volume ill a volume set. and the primary tilesystem can reside 011 another volume in the volume set.

Cupy"ym ~ 2006 Syrnanter Corporauon 1\11·,,;!hls reserved

VERITAS Storage Foundation 5.0 for UNIX Maintenance8-8

r-'~_~::----.::.---,p~11~r••.•.:1""iiffiJ..'~'r__---'~;;;;~-t~cWhy Use DST: Improve File Access Times

Problem: Too many infrequently accessed files can cause anenvironment to run slowly, Relocating the files can take careful

planning and E:jcan:a:~~ffiCUIt. {}'" . "" .1' ,,'I, ;,

. .• - J I ~ Server

. ow1999,2006

Solution: With OST, you can set up automatic relocation basedon the age of the file. Relocating your infrequently accessed

ru•• Improvesfile .c~, tlrnas 10'''';:(jServer

~;Q1999,2005 2006

Example 2

Jenkins and Roue, one of the nation's leading professional services firms, providesaccounting, tax management. and financial consulting services. Their data center isexperiencing performance slowdowns.

The billing application is running too slowly because there an: too many files onthe devices. Over time. their storage has become overloaded because of all thehistory information. They have many files, but most of the files arc not beingaccessed.

They need an easy way to move the files to other devices.

Challenge:

The system administrator has too much unaccessed data on the storage devices andit is causing slow access.

Solution:

Using OST, you can set up automatic relocation of the data based on age. Therelocation policies of OSTmakc identifying and moving the data easier. You canset up policies to move data to other cheaper, slower hardware.

This will increase performance on the most frequently accessed data.

8-9Lesson 8 Other Enterprise Features Overview

What Is Intelligent Storage Provisioning?The intelligent storage provisioning (lSP) feature ofVxVI'v1 provides a new way tocreate, organize. and manage volumes using policy-based templates that youconfigure to meet the performance and reliability requirements of yourenvironment. With ISP. volumes operate in the same way. have the same benefits,and have the same online administration features as traditionally created volumes.However. ISf> introduces new volume tunctionulity that enables you to standardizehow volumes are created, modi ficd. and managed.

Consciously or not. every organization implements storage provisioning policies.With ISI'. you can formally set the rules that govern storage provisioning.

To help you understand the concept of ISI' and the associated terminology. the nextfew slides present an analogy that compares storage provisioning to landdevelopment.

What Is Intelligent Storage Provisioning (ISP)?

Intelligent storage provisioning:

• Provides a new way to create, organize, and managevolumes

• Uses policy-based templates that you configure to meetthe performance and reliability requirements of yourenvironment

• Enables you to standardize how volumes are created,modified, and managed

To help you understand the benefits and purpose of ISP,the next slides present an analogy.

8-10Cupyr:ghl ~~,2006 Svruarnec Corporation All rights reserved

VERITAS Storage Founoeuon 5.0 for UNIX. Mamtenance

Analogy: "Traditional" Land Development(Without ISP)

Land for Housing Community (Disk Group)

~(Volume)

•

"~i.. , &'

, I

(Volume)

(Volume) (Volume) .

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(Volume)

(Volume)

• (Volume),111,/'" i!!.. v,

" I

!Iil.(Volume)

You sell the land and allow buyers to build whatever they want.

Traditional Land Development (Creating Volumes Without ISP)

Imagine that you are a land developer (slorage architcct/adnunistrutori who wantsto develop a residential housing community (slomgc (,11I'ir(lIllI1(,I1I), First. youestablish how much land you want to allocate to the housing community (1/7(' disk

group). Next. you start allocating land to interested buyers, selling ofT the land andbuilding whatever type of house (\'(Jlllllle) they want on that piece of land. Somebuyers may want only a small piece of land to build a modest house (small

COI1COICII(//cd volumeOil (//1 inexpensiveJilUD); other buyers may want a largepiece of land to build a luxurious mansion (large mirrored-striped I'OlulII<' Oil on

expensivearravv.

After all of the land is developed. the result is an uneven residential community inwhich no two houses are similar. no two lots arc of equal size or value, and there isan eclectic mix of neighbors with widely di ftcrcnt needs, The residents in themansion want security gates at all entrances (high reliabilitvi and paved roads(high pcrtormancc; throughout the community. Other residents do not care aboutsecurity and are content with gravel roads.

As you attempt to sort out the competing needs of the new residents. you wish thatyou had set some ground rules. established some standards for homcbuilders, andplanned the infrastructure for the community before you started selling land.

lesson 8 Other Enterprise Features Overview

Copvnqht" 2006 SymllntH Corrotanon All ncnts reserved.

8-11

alogy: Planned Community Development(With ISP)

Land for Planned Housing Community (Disk Group)

Open Space

Land for Houses~POOI) I

3·BR Floor plan• Living Room• Kitchen• Bedroom

4-BR Floor plan

• living Room• Kitchen• Bedroom

symantec.

Imagine that you arc a land developer tstorag« architect/administrators who wantsto develop a residential housing community (storag« environment). You arcexperienced in planned community development (intetligem storageprovisioning). First. you establish how much land you want to allocate to thehousing community (the disk gro/lp). You also determine that you want to maintainsome environmental barriers and open spaces within the community, so the actualarea that you plan to divide up lor housing (sioragl' pool) is not the full size or thecommunity (the disk gro/lp).

Your goal is tu maximize profit by fining as many houses and luts intu theremaining available space as possible, but you also wan I to establish a consistentstandard of living lor the community. You decide that your target market is middle-income families. so you decide to develop three- and four-bedroom single-familydwellings.

You hire an architect to develop t\\ u basic house designs. All residents or thecommunity will live in one or these prcdcsigncd houses tupplication volumes).The house 11001' plans lor these two house types are based on common roOI11designs that include a living room, kitchen, bedrooms, and bathrooms ttemplaresv.

With all of the details of the planned community in place. you are now ready tostart selling homes to interested buyers. And you already have a plan to create asecond community on adjacent land (clone pool) that is based on the first plannedcommunity (11011'. IIII' clutct pool). The second community will have 2-bcdroom and}-bedroolll homes tditterent temptatcs; and a target market of lower-middleincome lumilics (dif/i'rem slor(/g(' pools).

8-12

Planned Community Development (Creating Volumes With ISP)


ISP Structures

I Disk Gro_u_p

-,

I Data Pool

10StoragePools

Clone Pool

ApplicationVolumes

snapvolvol1 yol2

ElElElElElDisks In the Disk Group

Each storage pool consists of templates. Templates are collections of rulesthat specify performance and reliability capabilities for the application volumes.

ISP Structures

Storage pool: A policy-based container that resides inside a disk group and holdsapplication volumes

There are two types of storage pools:Data pool: A storage pool that contains your primary dataClone pool: A storage pool that contains snapshots of your primary data

Application volume: A volume created in a storage pool

An application volume is created with characteristics that are defined by thetemplates associated with the storage pool. If an application volume isreconfigured, rcsized, or relocated, the "intent" of the volume (that is, the originalcharacteristics of that volume that were set by the templates) is preserved.

Template: A collection of rules that specify performance and reliabilitycharacteristics for volumesStorage Foundation includes over Zf) predefined templates

CopyrlghlE 2006 Syrnantec Coroorano». All ncnts reserved

8-13Lesson 8 Other Enterprise Features Overview

---''''rn~ntP''

Why Use ISP: Snapshots (Not Using ISP)

It takes careful planning to ensure that the disks to beused for OHP are reserved solely for snapshots.

If snapshots and data volumes are on the same disk, you may not beable to split the disk group for OHP without first reorganizing storage.

Why Use ISP?

Example 1: Snapshots

Tripolyz Inc. uses snapshot volumes Ior off-host processing operations. includingbackup. testing. and decision support.

The system administrators arc finding it challenging to manage the amount of datain their systems. Frequently. the same storage devices are accidently allocated forboth data volumes and snapshot volumes. When the time comes to split olf asnapshot to move to another host. the administrator must rcconligurc the files toplace all the snapshot data 011 independent disks.

Challenge:

The system administrator needs to ensure that snapshots are not using the samedisks as data volumes.

Cup'if1ght ~ 2006 Symasuec Corporation {\Ii nqr-ts reserved

VERITAS Storage Foundation 5,0 for UNIX: Maintenance8-14

~---

Why Use ISP: Snapshots (Using ISP)With ISP, the planning is taken care of up front whenyou configure your ISP environment.

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The storage for snapshot volumes for OHP is separatedfrom the storage for data volumes.

Example I Solution

lSP enables the administrator to automatically place snapshots on separate storagefrom data volumes, Regulations are set up that affect volume configuration. Theseregulations cause the disks to be separated,

When you use lSP. there is an additional container in the disk group. called astorage pool. which can hold all the disks that you want to use for oft-hostprocessing. therefore keeping them separate from the disks used for data volumes,

Lesson 8 Other Enterprise Features Overview 8-15

'~~l-;;-~t;cWhy Use ISP: Control of Volumes (Not Using ISP)

If a department requests additional storage space for theirdata, administrators can fulfill that request however they want.

Original:Mirrored Concatenated 1 GB

More Space:Concatenated 2 GB

The administrator sacrificed redundancy for space byremoving the mirror to add more space to the volume.

Example 2: Control of Volumes

A S9 billion company whose data centers handle:a mission-critical salesmanagement system hasjust experienced a loss of data.

The sales processing department had asked for more space tor a new application.However, the system administrator who performed the spaceallocation was new.

He made a mistake when he assigned the spaceand broke their service-levelagreement. He increased their volume size by removing mirroring and adding theadditional space to the volume.

The company needs to prevent this from happening again. No matter who theadministrator is. then: must be consistency in administration and service-levelagreements must be maintained.

Challenge:

The system administrator needs to ensure that any new administrator has theappropriate inlormauon and docs not make an error.


· '~;';;l;mtec

Why Use ISP: Control of Volumes (Using ISP)With ISP, the administrator would have been prevented fromreducing the redundancy because of a regulation that was inplace.

Original:Mirrored Concatenated 1 GB

More Space:Mirrored Concatenated 2 GB

The administrator could not reduce redundancy and thereforehad to add more storage to provide more space in thevolume.

Example 2 Solutlon

When you use ISr, there is congruity in administration regardless of who is theadministrator. In this case. the administrator would have not been offered theoption of an unmirrored volume.

System administrators must understand the big picture and configure everythingappropriately. Because the big picture can also change-frequently. ISP is theprotection needed to preserve the original intent of the volumes.

There is no possibility that operations. such as grow, evacuate. add mirror. or addcolumn. can accidentally degrade the reliability or performance capabilities of avolume. Storage is automatically allocated based on stated requirements. such asthe desired capabilities of a volume.

Volumes can be created or grown safe in the knowledge that Isr will balance therequirements of all volumes.

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syrnantec

What Is the Storage Foundation ManagementServer (SFMS)?

The Storage Foundation Management Server provides:• Centralized management of diverse applications, servers,

and storage (from application to spindle)• Access across different operating systems, servers, and

storage arrays• A central interface• Comprehensive visibility and improved operational

efficiencies

Click here to view screens hotsof the new SFMS GUI

What Is the Storage Foundation Management Server?The Storage Foundation Management Server (SFMS) is a new GUI lor StorageFouudauon that provides centralized administration. management, monitoring. andreporting on Storage Foundation S.X and 4..v.

This is the Managing Summary window of the SFMS:

."


Copynqm 't, 2006 Svmantec Co.p.uaunn All nqhts reserved

••Lesson Summary• Key Points

This lesson introduced dynamic storage tiering, intelligentstorage provisioning, and the Storage FoundationManagement Server.

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• Reference Materials- VERITAS Storage Foundation Intelligent Storage

Provisioning Administrator's Guide- VERITAS Volume Manager Administrator's Guide- VERITAS File System Administrator's Guide

Lesson 8 Other Enterprise Features Overview

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8-19


Copvnqht c-2r.06 S)r11il"itK Corpnrauun /'1.11fights reserved

Appendix A

Lab Exercises

A-2 Education and SRT FrameMaker Template Set

CupYrighl {; 2005 Symantec Corporation All r'yl,ts reSfHYf!d

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Lab 1


For Lab Exercises, see Append~For Lab Solutions, see Append~~

Lab 1: Maintaining Data ConsistencyIn this lab, you practice recovering from a variety of plex problem scenarios. andoptionally, observe the benefits of a dirty region log during a system crash. Toinvestigate and practice recovery techniques. you will use a set of interactive labscripts. Each script:

Sets up the required volumesSimulates and describes a failure scenarioPrompts you to fix the problem

Prerequisite Setup

To perform this lab, you need a lab system with Storage Foundation pre-installed.configured and licensed. In addition to this. you also need a minimum of threeexternal disks to be used during the labs.

---------------------------------------------------Lab 1: Maintaining Data Consistency A-3

COpyright :f, 2fl06 Syrnantec Corporation /lll nqtus reserved

Classroom Lab Values

In preparation fur this lab, you will need the following information about your labenvironment. For your reference. you may record the information here, or referback to the first lab ill the SF Fundamentals section where you initiallydocumented this information.

Object Sample Value Your Value>-----'--I\Jy Data J)isks: Solaris: clt#dO -

clt#d5HP-UX c4tOdO -c4tOd5A)X:hdisk21-hdisk26l.inux: sda - sdf

Location of Lab Scripts: /student/labs/sf/sf50

A-4 VERITAS Storage Foundation 5.0 for UNIX: Maintenance

Preparation for Plex Recovery Labs

Overview

Your goal is to recover from the problem as described in each scenario. Use yourknowledge ofVxVM administration, as well as the VxVM recovery tools andconcepts described in the lesson, to determine what steps to take to ensurerecovery. After you recover the test volumes, the script verifies your solution andprovides you with the result. YOII succeed when you recover the volumes withoutcorrupting the data.

For most of the recovery problems, you can use any of the VxVM interfaces: thecommand line interlace, the VERITAS Enterprise Administrator (VEA) graphicaluser interlace, or the vxdiskadm menu interface. Lab solutions are provided foronly one method. I I' you have questions about recovery using interfaces notcovered in the solutions, see your instructor.

Setup

Due to the way in which the lab scripts work, it is important to set up yourenvironment as described in this setup section:

If your system is set to use enclosure-based naming, then you must turn offenclosure-based naming before running the lab scripts.

2 If you have a namedgdisk group left from previous labs, ensure that the diskgroup has no mounted fi le systems or volumes. I I' necessary, unmount anymounted file systems that arc on volumes in the narnedgdisk group andremove the volumes.

3 If you have not already done so, create a disk group named testdg and addthree disks (preferably of the same size) to the disk group. Assign thefollowing disk media names to the disks: testdgOL testdg02, andtestdg03.

Note: If you do not have enough disks, you can destroy disk groups created inother labs (for example, narnedg)in order to create the t estdg disk group.

4 Before running the automated lab scripts, set the DG environment variable inyour root profile to the name of the test disk group that you are using:Rerun your profile by logging out and logging back on, or manually running it.

5 Ask your instructor for the location of the lab scripts.

Lab 1: Maintaining Data Consistency A-5Copynght ,>"' 2U06 Svmantec Crsporanon !ill "gilts reserved

Resolving Plex Problems: Temporary Failure

In this lab exercise, a temporary disk failure is simulated By using the vxmendcommand, you must select the plcx that has the correct data and recover thevolume by using the clean plex. II' you select the wrong plex as the clean plcx, thenyou have corrupted the data. The lab script run_states sets up the test volumeconfiguration, simulates a disk failure, and validates your solution lor recoveringthe volume. Ask your instructor Ior the location of the run_st ates script.

Before You Begin: Check to ensure that the environment variable DG is set to thename ofthe testdg disk group:

From the directory that contains the lab scripts, run the script run_states,and select option I, "Turned 011'drive (temporary failure)":

This script sets up a mirrored I' otumc named test.

"10'1': I I'you receive an error messageabout the / image file system becomingfull during volume setup. ignore the error message.This error will not haveany impact on further lab steps or lab results.

2 Read the instructions in the lab script window. The script simulates a diskpower-off by saving and overwriting the private region on the drive that is usedby the volume. Then, when you arc ready to power the disk back 011, the scriptrestores the private region as it was before the failure.

3 Assume that the failure was temporary. In a second terminal window, attemptto recover the volume. Note that the second plcx is already in the STALE statebefore the drive fails.

4 Alter you recover the volume. type e in the lab script window. The scriptveri lies whether your solution is correct.

Resolving Plex Problems: Permanent Failure

In this lab exercise, a permanent disk failure is simulated. 8y using the vxmendcommand. you must select the plcx that has the correct data and recover thevolume hy using the clean plcx. If you select the wrong plcx as the dean plcx, thenyou have corrupted the data. The lab script run_states sets up the test volumeconfiguration. simulates a disk failure. and validates your solution for recoveringthe volume. Ask your instructor for the location of the run_states script.

Before You Begin: Check to ensure that the environment variable DG is set to thename of the testdg disk group:

A-6 VERITAS Storage Foundation 5.0 for UNIX Maintenance

COPYright;;, 2006 Syrnar:tp.c Co-porauon All rights reser veo

From the directory that contains the lab scripts, run the script run_states,and select option 2, "Power failed drive (permanent failure]"

This script sets up a mirrored volume named test.

Note: If you receive an error message about the / image file system becomingfull during volume setup, ignore the error message. This error will not haveany impact on further lab steps or lab results.

2 Read the instructions in the lab script window. The script simulates a diskpower-off by saving and overwriting the private region on the drive that is usedby the volume. I/O is started so that VxVM detects the failure, and VxVMdetaches the disk.

3 In a second terminal window, replace the permanently failed drive with either anew disk at the same SCS I location or by another disk at another SCSIlocation. Note that the new disk docs not have any data on it. The other plex ofthe volume became STALE ten minutes before the drive tailed. However, itstill has your data, but data from the last ten minutes is missing.

4 After you recover the volume, type e in the lab script window. The scriptverifies whether your solution is correct.

5 When you have completed this exercise, if the disk device that was originallyused during disk failure simulation is in onl ine inval id state, reinitializethe disk to prepare for later labs.

Resolving Plex Problems: Unknown Failure

In this lab exercise, an unknown failure is simulated. By using the vxmendcommand, you must select the plex that has the correct data and recover thevolume by using the clean plcx. If you select the wrong plcx as the clean plcx, thenyou have corrupted the data. The lab script run_states sets up the test volumeconfiguration and validates your solution for recovering the volume. Ask yourinstructor for the location of the run_states script.


From the directory that contains the lab scripts, run the script run_states,and select option 3. "Unknown failure":

Lab 1: Maintaining Data Consistency A-7Copynqm 'f. l006 Syruantec Corpcrauon All fights reserved

This script sets up a mirrored volume named test that has three plcxcs.

Note: l lyou receive an CITor message about the /image file system becomingfull during volume setup, ignore the CITor message. This error will not haveany impact on further lab steps or lab results.

2 Read the instructions in the lab script window. The script simulates anunknown failure that causes all plcxcs to be set to the STALE state. You arc notprovided with information about the cause otthc problem with the plcxcs.

3 In a second terminal window, check each plcx individually to determine it' ithas the correct data. To test i r the plcx has correct data, start the volume usingthat plcx, and then. in the lab script window. press Return. The script outputdisplays a message stating whether or not the plex has the correct data.Continue this process lor each plcx, until you determine which plex has thecorrect data.

4 After you determine which plcx has the correct data, recover the volume.

5 Aller you recover the volume. type e in the lab script window. The scriptveri lies whether your solution is correct.


Copynqnt :;,. 21106 Svmantec Corporation All fight'" reserved

Optional Lab ExercisesThe next set oflab exercises is optional and may be performed if yo II have time.These exercises provide additional recovery scenarios for resolving plex problemswith layered volumes. A final activity explores logging behavior following asystem crash.

Optional Lab: Resolving Plex Problems: Temporary Failure with aLayered Volume

In this lab exercise, a temporary disk failure is simulated. By using the vxmendcommand, you must select the plex that has the correct data and recover thevolume by using the clean plex. If you select the wrong plcx as the clean plcx. thenyou have corrupted the data. The lab script run_states sets up the test volumeconfiguration, simulates a disk failure, and validates your solution for recoveringthe volume. Ask your instructor for the location of the run_states script.


From the directory that contains the lab scripts, run the script run_states,and select option 4, "Turned off drive with layered volume":

This script sets up a concur-mirror volume named test.

Note: If you receive an error message about the / image file system becomingfull during volume setup, ignore the error message. This error will not haveany impact on further lab steps or lab results.

2 Read the instructions in the lab script window. The script simulates a diskpower-offby saying and overwriting the private region on the drive that is usedby the volume, and I/O is started so that VxVM detects the failure. Then, whenyou are ready to power the disk back on, the script restores the private regionas it was before the failure.

3 Assume that the failure was temporary. In a second terminal window, attemptto recover the volume. Note that the second plcx is already in the STALE statebefure the drive tails.

4 After you recover the volume, type e in the lab script window. The scriptverities whether your solutiun is correct.

Lab 1: Maintaining Data Consistency A-9Coryngill 'f 2006 Svmanter Corporation. All flgnls reservec

Optional Lab: Resolving Plex Problems: Permanent Failure with aLayered Volume

In this lab exercise, a permanent disk failure is simulated. By using the vxmendcommand, you must select the plcx that has the correct data and recover thevolume by using the dean plcx. I f you select the wrong plcx as the clean plcx, thenyou have corrupted the data. The lab script run_states sets up the test volumeconfiguration, simulates a disk failure, and validates your solution for recoveringthe volume. Ask your instructor for the location of the run_states script.


from the directory that contains the lab scripts. run the script run_states,and select option 5, "Power failed drive with layered volume":

This script sets lip a concat-mirror volume named test.

Note: If you receive an error messageabout the / image file system becominglull during volume setup. ignore the error message.This error will not haveany impact on further lab steps or lab results.

2 Read the instructions in the lab script window. The script simulates a diskpowcr-oflby saving and overwriting the private region on the drive that is usedby the volume. 1;0 is started so that VxVM detects the failure. and VxVMdetaches the disk.

3 In a second terminal window, replace the permanently failed drive with either anew disk at the same SCSI location or by another disk at another SCSIlocation. Note that the new disk docs not have any data on it. The other plcx ofthe volume became STALE ten minutes before the drive failed. However, thisplcx still has your data. but data from the last ten minutes is missing.

4 ABel' you recover the volume, type e in the lab snip! window. The scriptverifies whether your solution is correct.

5 When you have completed this exercise, destroy testdg.

A-10 VERITAS Storage Foundation 5,0 for UNIX: Maintenance

Copvnqtu r 2006 Symantec Cocrorauon All !'gllls reserved

Optional Lab: Exploring Logging Behavior During a System Crash

'ote: This section requires console access to the lab system. If you are working ina Virtual Academy lab environment. skip this section.

List the imported disk groups on your system and destroy the testdg diskgroup if it still exists.

2 If you do not already have a disk group called namedg, create it using one ofthe already initialized disks.

3 Ensure that the namedg disk group has at least three disks in it. Ifnecessary,add disks to the namedg disk group.

4 Create two mirrored, concatenated volumes, 'iOO MB in size, called v o Ll oqand vo l no l oq in the namedg disk group.

5 Add a log to the volume vo I Loq.

6 Create a file system on both volumes.

7 Create mount points for the volumes, /vo110g and /vo1no10g.

8 Copy /etc/vfstab (on Solaris) or /etc/fstab (on Linux and III'-lIX) toa tile called origvfstab or origfstab.

9 Edit /etc/vfstab or /etc/fstab so that voI Loq and vol no Loq aremounted automatically on reboot. (In the file, each entry should be separatedby a tab.)

Nore: On the Solaris platform. ensure that you set the mount at bootoption to yes for both file systems.

10 Type mountall (on Solaris and HI'-UXl or mount -a (on Linux) to mountthe vo l Loq and vo l no l oq volumes.

11 In root, start an I/O process on each volume. For example:

12 Simulate a system crash on your system by stopping it unexpectedly as shownin the following.

13 After the system is running again, check the state of the volumes to ensure thatneither of the volumes is in the sync/need sync mode.

Note: If you are not using file system logging for boot disk file systems,youmay need to carry out tile system checks for boot disk tile systems on theconsole before the system becomes operational again.

Lab 1: Maintaining Data Consistency A-11

Cnpyngtll '~.2006 Svmantf!r. Corporation All r-ents ''''SAP,eo

14 Run the vxstat command as shown in the Iollowing. This utility displaysstatistical information about volumes and other VxVM objects. For moreinformation on this command, see the vxstat (1m)manual page.

The output shows how many I/Os it took to rcsynchronizc the minors.Compare the number of I/Os lor each volume, What do you notice"

15 Uumount both file systems and remove the volumes vollog and volnolog.

16 Restore your original vfstab or fstab file.

17 Destroy the namedg disk group.


Copvrtqht ~ 2006 Svmantec Corporanon All rlW,ts reserveo

symantec.

Lab 2


Lab 2: Managing Devices Within the VxVM ArchitectureIn this lab, you explore the VxVM tools used to manage the device discovery layer(DOL) and dynamic multipathing (OM!». The objective ufthis exercise is tu makeYOll familiar with the commands used to administer multipathed disks.

In the VERITAS classroom (not Virtual Academy). you also explore dynamicmultipathing through the use of two ports un the liDS disk array. In the classroomconfiguration, each I..UN maps to two pons on the liDS, so that a system detects aLUN twice through a single IIBA. Your instructor will change the classroomconfiguration at a certain point in the lab to enable access to the II OS ports,effectively switching from one path to two paths to each LUN.

I For Lab Exercises, see Appendix A.L. For Lab Solutions, se~Appendi~~

Prerequisite Setup

Tu perform this lab. you need a lab system with Storage Foundation pre-installed,configured and licensed. In addition to this, you also need a minimum of threeexternal disks to be used during the labs.

Nute: Pan 1 of this lab can only be performed in the standard VERITASclassrooms that include an liDS disk array.

Before you begin this lab. destroy any data disk groups that are left from previouslabs:

vxdg destroy diskgroup

Lab 2: Managing Devices Within the VxVM Architecture

Copvnqtu '(" 2006 Symaorer Corporation All fights reserved

A-13


In preparation lor this lab. you will need the following information about your labenvironment. For your reference, you may record the information here, or referback to the first lab in the SF Fundamentals section where you initiallydocumented this information.

Object Sample Value Your Valueroot password veritas

Host name trainl

My Data Disks: Sol.uis: clt#dO -clt#d5HP-liX: c4tOdO -

c4tOd5AIX: hdisk2l-hdisk26l.inux: sda - sdf

Location of Lab Scripts: /student/labs!sf/sf50

Location of the fp /student/labs/sf/program: sf50/bin

A-14 VERITAS Storage Foundation 5,0 for UNIX: Maintenance

Copyr'\lht o 2006 Sv-namec Corporation All rights reserved

Introduction to DMP Labs

To explore the behavior of DMP in the classroom, this lab is organized into twosections:

Part I: In this activity, you practice using DDL and DMP administrativecommands while only one path is visible to each LUN.Part 2: In this activity, the instructor changes the classroom configuration sothat each LUN maps to both ports on the liDS, and each system detects twopaths to a LUN. Explore additional exercises to experience when two paths arein use.Note: Part 2 can only be performed in a standard Symanrec classroom (not in aVirtual Academy or Mobile Academy lab environment).

Instructor Classroom Setup

Instructor: If you did not initialize the classroom zoning configuration prior to thestart of class on day one, perform the following steps to initialize classroom zoningconfigurations. This must be completed prior to performing this lab.1 Use course_setup script: Select Classroom.

(Setup scripts are all included in Classroom SAN configuration Version 2).Select Function To Perform:

Select Zoning by Zone Name2 - Select Zoning and Hostgroup Configuration by Course Name

3 Select/Check Hostgroup Configuratlon

2 Select option 3 - Select/Check Hostgroup Configuration.Select HostGroup Configuration to be Configured:1 - Standard Mode: 2 or 4 node sharing, No DMP2 DMP Mode: 2 node sharing, switchable between 1 path and 2path access

Check active HDS Hostgroup Configuration

3 Select option 2 - DMP Mode. Wait and do not respond to prompts.4 Exit to first level menu.5 Select option I - Select Zoning by Zone Name.

Select Zoning Configuration Required:1 - Mode 1: 6 sets of 2 Systems sharing 12 LUNs, no Tape Libraryavailable (HDS DMP Mude - 6 x 2 Systems - Single Path to 12LUNsl2 - Mode 2: 3 sets of 4 Systems sharing 24 LONs, no Tape Libraryavailable (HDS DMP Mode - 6 x 2 Systems - Dual Paths to 12 LUNsl

6 Select option I - Mode I (single path to 12 LUNs).7 Select option 4 - Solaris as the US.a Exit out of the course_setup script.9 Reboot each system using reboot - - - L

Lab 2: Managing Devices Within the VxVM Architecture

Copyright 20()6 Symanter Corpo-auo» All «qnts .eservec

A-15

Part 1: Exploring DMP (Single Path Visible)

Administering the Device Discovery Layer

Display the JI30Ds currently supported on your system by using VxVM'sdevice discovery layer utility, vxddladm. Use manual pages to identity theoption you need to use with the vxddladm command.

2 List all currently supported disk arrays.Note: I r your lab environment is using Hitachi 9500 array, note that this arrayis included in the libvxhdsalua library that is already included in VxVM5.0 by default.

3 List all the enclosures connected to your system using the vxdmpadm1istenclosure all command. Docs volume Manager recognize the diskarray you arc using in your lab environment? What is the name oftheenclosure'?

4 Set your system to use enclosure-based naming.

5 Display the disks attached to your system and note the changes.

6 Rename the enclosure to yournameusing the vxdmpadm setat trcommand. To find the exact command syntax, check the manual pages tor thevxdmpadmcommand.Note: The original name ofthe enclosure is displayed by the vxdmpadmlistenclosure all command that you used in step 3.

7 Launch VEA. connect to your local system, and notice any differences ill howdisks arc represented.

Displaying DMP Information

L.ist all controllers on your system using the vxdmpadm 1i stct lr allcommand. How many controllers arc listed for the disk array your system isconnected to'?

2 Display all paths connected to the controller listed lor the disk array on yoursystem using the vxdmpadm getsubpaths ctlr=controllercommand. Compare the NAME and the DMPNODENA~1E columns in the output.


Copvnqnt 2(j()6 Symatuec Cmporaliot] 1\11fights reserved

3 In the displayed list ofpnths.use the DMP node name of one of the paths todisplay information about paths that lead to the particular LUN. How manypaths can you see')

In the next three sections you will investigate preventing multipathing to a specificdevice, changing DMP 110policies. and displaying DMP statistics. If you areworking in an environment where the SAN zoning can be changed to provide dualpaths to the disk devices. for exampit: in a standard Symanrec classroom. skipthese sections and start with Part 2 Exploring OM P (Dual Paths Visible). The samesections will be repeated when dual paths to disk devices are available.

Note: Dual paths to disk devices are not available in Virtual Academy or MobileAcademy lab environments.

Lab 2: Managing Devices Within the VxVM Architecture A-17Copynqm 'f: 2006 Symantec Corporation All nqnts reserved

Preventing/Allowing Multipathing for a Device

~ol(': Perform this section only ifyou cannot change your environment to use dualpaths to disks. Otherwise. skip to Part 2 Exploring DMP (Dual Paths Visible).

1 List the paths fur each DM P node name displayed in the enclosure basednaming scheme to identify two of the disks that were assigned to you.

Nute: Alternatively. you can use the output of the vxdmpadmgetsubpaths ctlr=controllercoml11and to find the pathcorresponding to each drnp node name. On the Solaris platform, the vxdisk- e 1 is t command also provides information about the native OS name thatcorresponds to each dmp node name.

2 Create a disk group named namedg that contains the two disks you identifiedin step I.

3 Display multipathing information for one of the disks ill the namedg diskgroup.

4 Select a device in the namedg disk group on your system, and preventmultipathing for that device. Note that you have to exit the vxdiskadm menucompletely before the change takes affect.

Note: When you arc prompted to enter the disk name. you have to enter theactual device name, not the OM P node name. On the Solaris platform, you canuse the list option to identify the actual device names that correspond to the[)MP node names.

5 Veri fy that multipathing has been prevented fur the device.

6 Run the vxdisk -0 alldgs list command and notice the name andlocation of the disk in the list.

7 Rc-cnablc muliipathing for this device and verily your action. Note that youhave to exit the vxdiskadm menu completely before the change takes affect

Note: Depending on your plauorm. the vxdiskadm menu may prompt you toreboot your system. Reboot your system itprompted by the vxdiskadmmenu.

8 Run the vxdisk -0 alldgs list command and notice the names andlocution 01" the disk in the list.

A-18 VERITAS Storage Foundation 5.a for UNIX: Maintenance

Copyflqtll ~ ;:006 Svrnantec Corpcr auon J\II "yhls reserved

Displaying DMP Statistics

Note: Perform this section only if you cannot change your environment to use dualpaths to disks. Otherwise, skip to Part 2 Exploring OMP (Dual Paths Visible).1 Create a 1-(iB volume named namevoll in the namedg disk group.

2 Enable the gathering of I/O statistics for DMP.

3 Resctthe DMP I/O statistics counters to zero.

4 Next, you will use a simple performance utility, called f p. to generate I/O onthe disk used by the namedg disk group. Ask your instructor for the locationof the program. In a different terminal window, start several invocations of thefp program by using the following command:/8cI'ipt_loc~t'i('i-)!fp_plAt'foI'i!:

/dev/vx/rdsk/n3;n,'·dg/na'i1c,voll 1048.576 32 99999 rw &

To create enough 110 resistance, LIsethe vi editor and CllPY about 10 of theselines into a file called /tmp/testscript. and then rUII the script:'Iote: Make sure that you are using the correct version of the fp program foryour platform, for example, fp_sun.

5 In the original terminal window, display 110 statistics for all controllers.

6 Display I/O statistics for the DM P node that corresponds to the device used bynamevoll. Display statistics every two seconds lor four times.~flte: You can use the vxprint. -g namedg -ht.r namevollcommand to identify the drnp node name of the device used by namevoll.

Managing Array Policies

Note: Perform this section only if you cannot change your environment to Lisedualpaths to disks. Otherwise, skip to Part 2 Exploring DMP (Dual Paths Visible).1 Display the current 110 policy for the enclosure you are using.

2 Change the current I/O policy for the enclosure to stop load-balancing and onlyLisemultipathing for high availability.

3 Display the new I/O policy attribute.

4 Kill all fp processes.

A-19Lab 2: Managing Devices Within the VxVM Architecture

Copynqht 'C; 200f) Syrnantec Corporation All «ctus reserved


6 Set your system back to traditional naming.

A-20 VERITAS Storage Foundation 5.0 for UNIX. Maintenance

Copvnqhl: 200n S,'rJ1ilHler. Corporanou All rights reserved

Part 2: Exploring DMP (Dual Paths Visible)

Note: The following labs arc intended for a multipath environment and do notmake sense with a single path. These activities may be performed only in theSymantec classroom environment. nut in the Virtual Academy or Mobileenvironments.


Instructor: Perform the following steps to switch dual paths on. Switch to zonecontiguration 2 to enable a second path to the LUNs:

Use course_setup script: Select Classroom. Setup scripts are all includedin Classroom SAN configuration (Version 2).Select Function To Perform:

Select Zoning by Zone Name

2 - Select Zoning and Hostgroup ConEiguration by Course Name3 Select/Check Hostgroup Configuration

2 Select option 1- Select Zoning by Zone Name.Select Zoning Configuration Required:

1 - Mode 1: 6 sets of 2 Systems sharing 12 LUNs, no Tape Libraryavailable (HDS DMP Mode - 6 x 2 Systems - Single Path to 12LUNs)

2 - Mode 2: 3 sets of 4 Systems sharing 24 LUNs, no Tape Libraryavailable (HDS DMP Mode - 6 x 2 Systems Dual Paths to 12 LUNs)

3 Select ? to switch to dual paths.

4 Select option 4 - Solaris as the OS.

5 Exit out of the course_setup script.

6 Reboot each system using reboot - L


List all controllers on your system using the vxdmpadm 1i stct lr allcommand. How many controllers are listed for the disk array your system isconnected to')

2 Display all paths connected to the controller listed for the disk array on yoursystem using the vxdmpadm getsubpaths ctlr~controllercommand. Compare the NAME and the DMPNODENAME columns in the output,

Lab 2: Managing Devices Within the VxVM Architecture A-21Copyright ,t, 2006 Symantec Corporanon 1\11fI~l~lls reservec

3 In the displayed list of paths, use the DMP node name of one of the paths todisplay information about paths that lead to the particular LUN. How manypaths can you see?


List the paths for each drnp node name displayed in the enclosure basednaming scheme to identify two of the disks that were assigned to you.

2 Create a disk group named namedg that contains the two disks you identifiedin step I.

3 Display mulupathing information Ior one of tile disks in the namedgdiskgroup.

4 Select a device in the namedgdisk group on your system, and preventmultipathing for that device. Note that you have to exit the vxdiskadm menucompletely before the change takes affect.Note: When you arc prompted to enter the disk name, you have to enter theactual device name, not the drnp node name. On the Solaris platform. you canuse the list option to idcnti fy the actual device names that correspond to thedmp node names.

5 Verify that multipathing has been prevented lor the device.

6 Run the vxdisk - 0 alldgs 1 ist command and notice the names andlocation of the disk in thc list.

7 Rc-cnablc multipathing for this device and verify your action. You need toenable multipathing for both paths of the device. Note that you have to exit thevxdiskadm menu completely before the change takes affect.

Note: Depending on your platform. the vxdiskadm menu may prompt you toreboot your system. Reboot your system ifprompted by the vxdiskadmmenu.

8 Run the vxdisk -0 alldgs 1 ist command and notice the names andlocation or the disk ill the list.


Cupyflyht <l.. 2006 Syoranrer Cou-oranon All rights reserved


Create a I-GB volume named namevoll in the namedg disk group.

2 Enable the gathering of I/O statistics for or",! p.

3 Reset the DM P I/O statistics counters to zero.

4 Next, you will use a simple performance utility. called f p, to generate I '0 onthe disk used by the namedg disk group. Ask your instructor for the locationof the program. In a different terminal window. start several invocations of thefp program by using the following command:

!dev!vx/rdsk/iLunedg!n:iln.,o·voll 1048576 32 99999 rw &

To create enough 110 resistance. use the vi editor and copy about 10 oftheselines into a file called /tmp/testscript, and then run the script

Note: Make sure that you are using the correct version of the fp program foryour platform. for example, fp_sun.

5 In the original terminal window, display I-O statistics for all controllers.

6 Display I/O statistics for the DMP node that corresponds to the device used bynamevoll. Display statistics every two seconds for four times.

;\ote: You can use the vxprint -9 namedg - htr namevollcommand to identify the drup node name of the device used by namevoll.



Display the current 1/0 policy for the enclosure you are using

2 Change the current I/O policy for the enclosure to stop load-balancing and onlyuse multipathing for high availability.

3 Display the new 110 policy attribute.

4 Reset the DMP 10 statistics counters to zero.

5 Next, YOLIwill Lise the fp program again. to generate 110 on the disk used bythe namedg disk group. Ask your instructor till' the location of the program. In

A-23Lab 2: Managing Devices Within the VxVM Architecture

CopyrFg~11 ,t 2006 Syrnantec Corpor.mon 1\11 notus reserved

a di Herem terminal window, start several invocauons of the fp program byusing the following command:

/dev/vx!rdsk/:""""'dg/']",,,ic"voll 1048576 32 99999 rw &

To create enough I/O resistance, use the vi editor and copy about IU olthcsclines into a file called / tmp/ testscript, and then run the script.

Note: Make sure that you arc thing the correct version of the fp program for)OUI platform. for example, fp sun

6 In the original terminal window, display I/O statistics for all controllers,

7 Display I/O statistics for the DMP node that corresponds to the device used bynamevoll. Display statistics every two seconds for four times. Compare theoutput to the output you observed be lure changing the DMI' policy tosinglcucuv c.

Note: You can use the vxprint -g namedg -htr namevollcommand to idcnii Iy the dmp node name of the device used by namevoll.


9 Change the DMI' 1/0 policy back to its default value (round-robin).

10 Destroy the namedgdisk group.


Managing the DMP Restore Daemon

Check the status ofthe DM!' restore daemon.

Note the values of the daemon interval and policy.

2 Change the restore daemon interval to 400 seconds and change thc policy toanalyze all paths in the system.

3 Veri Iy the changes that you made.

4 Change thc daemon interval and policy back to the original values.

5 Veri Iy the changes that you made.


symantcc.

Lab 3


For Lab Exercises, see APpen. dix A. 1For Lab Solutions, see Appendix B.

Lab 3: Encapsulation and RootabilityIn this practice, you create a hoot disk mirror. disable the boot disk, and boot upfrom the mirror. Then you boot up again from the boot disk. break the mirror. andremove the boot disk from the boot disk group. Finally. you reencapsulate the bootdisk and re-create the mirror. These tasks are performed using a combination of theVEA interface. the vxdiskadm utility, and ell commands.

The Lab Solutio", j,'r Ihis lab <I,.,' locak" on Tile foll""ili!! P;i!!,'

Prerequisite Setup

To perform this lab, you need a lab system with Storage Foundation pre-installed.configured and licensed. In addition to this. you also need a second internal disk tobe able to mirror the system disk.

On the IIP-UX platform, you also need three external disks to carry out the labs onLVM to VxVM conversion.

Some of the lab steps may require console access. If you are working in a VirtualAcademy lob environment where you do not have console access to the lab system.you will be asked to skip these steps.

Lab 3: Encapsulation and Rootability A-25Copyngtlt i) l006 Symantac Corporauon A.II rights r!"server1


In preparation for this lab, you will need thc following information about your labenvironment. For your reference, you may record the information here, or referback to the first lab in the SF l-undamcntals section where you initiallydocumented this information.

Object Sample Value Your Value

root pass" ord veritas

Host name trainl

l\Iy Boot J)isk: Solaris:cOtOdO

HP-L,X: clt15dO

AIX: hdiskO

l.inux: hda

2nd Internal Disk: Solaris: cOt2dO

HI'-LX: c3tl5dO

AIX: hdiskl

l.inux: hdb

l\Iy Data Disks: Solaris: c 1t#dO -

clt#d5

HI'-I;X: c4tOdO -c4tOd5

AI:'\: hdisk21-hdisl:26

L inux: sda - sdf


Copvnqm ~~2006 Svm-uitec Corporal Ion All rlghlS -eserveo

Solaris and Linux Only: Encapsulation and Boot Disk Mirroring

NOll': The encapsulation and hoot disk mirroring labs vary by platform due to theway in which the boot disk is handled by the operating system. This labsection applies to Solaris and Linux only. Labs for IfP-UX are presented inthe next section.

Encapsulation and Boot Disk Mirroring. Solaris and Linux

Use vxdiskadm to encapsulate the boot disk. Use systemdg as the name ofyour boot disk group and use rootdisk as the name of your boot disk.

NOll': If you are accessing your lab system remotely as in a Virtual Academylab environment. you will lose your connection to your lab system when youreboot your system after boot disk encapsulation. Wait for the system to comeback up to reconnect. If you cannot log back in within a reasonable amount oftime. contact your instructor.

2 After the reboot, use vxdi skadm to add a disk that will be used for the mirrorof rootdisk. If your system has two internal disks. use the second internaldisk on your system for the mirror. (This is required due to the nature of theclassroom configuration.) When setting up the disk. ensure that the disk layoutis s I iced. Use a I tboot as the name of your disk.

3 Next. use vxdiskadm to mirror your system disk. rootdisk. to the diskthat you added. a 1 tboot.

4 After the mirroring operation is complete, verify that you now have two disksin systemdg: rootdisk and a I tboot, and that all volumes are mirrored.Also. check to determine ifrootvo1 is enabled and active.

Hint: Use vxprint and examine the STATE fields.

5 Place the names of your alternate boot disks in persistent storage.

Nore: The following steps (steps (i-II) in this lab section require console access. Ifyou are working in a Virtual Academy lab environment with no consoleaccess. skip to the last step (step 12) of this section.

6 Test that the mirror of the system disk is bootablc.

7 Now that you are running offthe original boot disk. fail the disk. The systemwill continue to run because you have a mirror of the disk.

a Fail the system disk.

Lab 3 Encapsulation and Roolability A-27

Copyn9hl~) 2006 Symante- Corroranon. All rights reserved

11.) disable till; boot disk and make rootvol- 01 disabled and offline, usethe vxmendcommand. This command is used to make changes tocontiguration database records. Here, you arc using the command to placethe plcx in an offline state. For more information about this command, seethe vxmend (Lm) manual page.

b Verify that rootvol- 01 is now disabled and offline.

c To change the plcx to a STALE state, run the vxmendon command onrootvol- 01. Verify that rootvol- 01 is now in the DISABLED andSTALE state.

8 Now that you have simulated the failure of the original boot disk, reboot thesystem and boot up on the mirror.

a Reboot the system using ini t 6.

b The system stops during the reboot at the OK prompt and indicates for youto use vx -a I tboot. \30(l\ from the alternate boot disk

9 Alter the system comes back up, check the status of the root volume, What isthe state of the volume'?

Use the vxtask 1i s t command to see the progress of the rcsynchronizationof the root volume.

10 Alter the synchronization is complete, verify the status of rootvoL Verifythat rootvol- 01 is now in the ENABLED and ACTIVE statc.

Note: You may need to wait a few minutes for the state to change from STALEto ACTIVE.

You have successfully booted up Irorn the mirror, and the volumes have beenrcsynchronizcd.

11 Your system is currently booted up li·0I11 the boot disk mirror. To boot up fromthe original boot disk, reboot again using ini t 6.

You have now booted up from the original boot disk,

Not«: If you arc working in a Virtual Academy lab environment with no consoleaccess, you call continue with step 12.

12 Remove the mirror of the boot disk. Using VEA, remove all but one plex ofrootvol, swapvol, usr, var. opt, and home(that is, remove the newerplcx from each volume in systemdg).

III preparation for the next lab, leave the boot disk encapsulated, but not mirrored,


Copyright:; 2006 Symamer Corporation All rights ff:!$fHVt=;d

Optional Lab: Unencapsulating - Solaris and Linux

If you want to test the vxunroot process for uncncapsulating the hoot disk, youcan do the following steps. l lowcver, you need the boot disk encapsulated for thenext lab. So after performing this optional exercise, you will need to encapsulate,but not mirror, your boot disk.

Run the command to convert the root volumes back to disk partitions.

2 Shut down and restart the system when prompted.Xote: If you are accessing your lab system remotely as in a Virtual Academylab environment, you will lose your connection to your lab system when youreboot your system. Wait for the system to come back up to reconnect. IfYl1Ucannot log back in within a reasonable amount of time, contact your instructor.

3 Verify that the mount points arc now slices rather than volumes.

4 In preparation for the next lab. leave the boot disk encapsulated, but notmirrored.

Lab 3: Encapsulationand Rootability A-29Copynght'f 2006 Symantec Corporanon. Auuntus reserved

HP-UX Only: Putting the Boot Disk Under VxVM Control and Boot DiskMirroring

Note: The encapsulation and boot disk mirroring labs vary by platform due to theway in which the bout disk is handled by the operating system. Thefollowing lab sections apply to HP-UX only. Labs lor Solaris and Linux arcpresented in the previous sections.

Putting the Boot Disk Under VxVM Control and Boot Disk Mirroring·HP·UX

Note: This lab section requires console access. If you arc working in a VirtualAcademy lab environment with no console access.skip this lab section andgu to the LVM tu VxVM Conversion lab section.

Take the system into single user mode (init level I).

2 Check the status of the second internal disk using the vxdi sk 1 i s tcommand. I I' the disk is displayed as an LVM disk. ensure that it is not used byany active LVM volume groups and take it uut of LVM control using thepvremove command.Note: If the pvremove command 1(liisdue to an exported volume groupintorrnatiun left un the disk, IT-create an LVM header using the force option(pvcreate - f / dev / rdsk/ device_name) before using thepvremove command to remove it.

3 Check the values ofthe primary and alternate boot devices using the setbootcommand.

4 Create a bootablc VxVM system disk on the second internal disk using thcvxcp _1vmroot command and make this disk the primary boot disk. Usesystemdg as the disk group to put the boot disk in.

5 When the vxcp 1vmroot command completes. check the output ul thesetboot command and verify that the primary path is the VxVM disk.

6 Reboot the system. Alter it boots up, verily that it is booted on Vx VM volumesby checking the output of the bdf command.

7 Destroy the internal disk that was used as the LVM system disk.

8 Mirror the system disk to the other internal disk that used to he the LVM disk.


Coovnclu ~,2006 Symaruec Corporation (III nqhts reserved

Note: This operation can take some time depending on the sizes of thevolumes on your system disk.

9 Verify the primary and alternate hoot paths and check the volume layouts ofthe volumes in the bootdg.

10 Reboot your system using shutdown -ry now and interrupt the automaticboot process.

11 Boot the system using the alternative boot disk.

12 When the system is up, disable the root volume plex that is on the primary bootdevice using the vxmend of f command followed by vxmend on.

13 Reboot your system using shutdown - ry now and follow the boot-upmessages. What did you observe'

14 Reset the system using Service Processor login as follows:

15 Interrupt the automatic boot process and boot the system using the alternateboot device.

16 When the system is up and running display the state of the root volume andplcxcs. Check if there are any synchronization tasks being carried by volumemanager using the vxtask 1ist command. Wait for the synchronization tocomplete.

17 When the state of the first rootvol plcx changes back to ACTIVE. remove thesecond mirrors on the alternate disk from each volume. Take the alternate diskout of the disk group and uninirialize it.

18 Take the system to single user mode by executing ini t 1.

19 Create a copy of the system disk on an LVM disk using thevxres 1vmroot command. Do not make the LVM disk the primary bootdisk.

20 Reboot your system using shutdown - ry now and interrupt the automaticboot process.


22 When the system is up, verify that the system is booted on the LVM disk byexecuting the bdf command. and display the f lc system table and the/ stand/boot conf tile.

Lab 3: Encapsulation and Rootability A-31COpYrighl {' 200n Symantec Corpo-anoo. 1\11rlght<; reserved.

23 Reboot your system using shutdown -ry now and when the system isback up verify that the system is booted on YxYM volumes. and display thefile system table and the / stand/booteonf tile.

LVM to VxVM Conversion - HP-UX

Create two LYM physical volumes using the pvereate command on twouninitializcd external disks as follows:

pvereate /dev/rdsk/device~taglpvereate /dev/rdsk/device_tag2Note: If you do not have enough uniniualizcd external disks, youlllay need touninitializc the empty disks that arc under YxYM control before creating theLVM physical volumes.

2 Create a volume group called vgOl using the physical volumes as follows:

mkdir /dev/vgOlmknod /dev/vgOl/group e 64 Ox020000vgcreate /dev/vgOl /dev/Jsk/device~tagl \

/dev/dsk/device~tag2

3 Using the 1verea te command, create two logical volumes, oneconcatenated and one striped, of size IOUMl3 in the vgOl volume group asfollows: (Use 32K as the stripe unit)

Ivereate -L 100 -n eoncatvoll /dev/vgOlIvcreate -i 2 -I 32 -L 100 -n stripevoll /dev/vgOl

4 Make vxls file systems on both volumes and mount them to two newdirectories called /concat and /stripe.

5 Edit the /etc/fstab tile and create the corresponding entries for the filesystems by adding the following lines:

/dev/vgOl/concatvoll /coneat vxfs log 0 2/dev/vgOl/stripevoll /stripe vxfs log 0 2

6 Using the vgcfgbackup command. back up the LYM configuration for thevolume group that you created in the first part of the lab.

7 Unmount the file systems and run the conversion tool: vxvmconvert.

8 Examine the file /ete/fstab. and the directories /dev/vgOl and/ dev / vx/ [r J dsk. What changes have been made?

9 Change the volume name of eoncatvollto volOl alter the conversion.

Change the corresponding / ete/ f stab entry to:

VERITAS Storage Foundation 5.0 for UNIX: MaintenanceA-32Copy'fOyill!';, 2006 Svmautec Corporauo« All flghls reservec

/dev/vx/dsk/dgOl/volOl /concat vxfs log 0 2

10 Remount the file systems.

11 After the conversion to VxVM completes successfully, create a VxVM diskgroup called testdg on another external disk.

12 Unmount the tile systems and roll back to LVM configuration usingvxvmconvert option 3. What did you observe')

13 Remove the entries for /concat and /stripe from /etc/fstab.

14 Using the Ivremove command. remove the volumes concatvoll andstripevol1.

15 Destroy the volume group vg 01.

16 Convert the empty LVM physical volumes to VxVM by removing them fromLVM control and then initializing them using VxVM.

17 Destroy the testdg disk group,

Lab 3: Encapsulation and Rootability A-33

Copvnqtu e, 2006 S~11l8'1IAr. Coroo-enon !\II «qtvs reserved


Copvnqht 'E" 2006 Symamec cororenoo All flgl~ls reserved

Lab 4



Lab 4: Troubleshooting the Boot ProcessIn this lab, you practice recovering from encapsulated boot disk failure scenarios.On the Solaris platform. tu investigate and practice recovery techniques, you willuse a set of interactive lab scripts. Each script simulates a failure in theencapsulated boot disk (and its mirror, ifrequired) and reboots the system.

TIK Lab Sohuiou-. il)r this lab arc' loc.ucd on the !c)lIll\yill", I''''''c:

"I.nb ..) Solurion-: fmuhksh"'lilllic rhc Il"ot Pt\lCl>S." pilgc' Il·:; I

Prerequisite Setup

To perform this lab, you need a lab system with Storage Foundation pre-installed,configured and licensed. In addition to this. you also need a second internal disk tobe used as an alternative boot disk.

If you have completed the previous labs. you should have the following setup:

On the Solaris platform. you should have your system disk under Vx VMcontrol (encapsulated) but not mirrored.

On the IIP-UX platform. you should have the system disk under VxVMcontrol and you should have the second internal disk configured as analternative LVM boot disk.

:\ote: This lab requires console access. If you are working in a Virtual Academylab environment with no console access. you cannot perform this lab.

Lab 4: Troubleshooting the Boot Process

Coovnqnt fi", 2(106 Svmantec Corporanon All fights -eserveo

A-35


In preparation for this lab. you will need the following information about your labenvironment. For your reference, you may record the information here, or referback to the first lab in the SF Fundamentals section where you initiallydocumented this information.


Host name t ra i n l

Host name of the system train2sharing disks \\ ith mysystem1\1)Boot Uisk: Sol.iris: cOtOdO

HP-LX: cltl5dO

AIX: hdiskO

l.inux: hda


HP-LX: c3t15dO

AIX: hdiskl

Liuux: hdb

Location of Lab Scripts: /student/labs/sf/sf 50


Cupyflyhl ( 2006 Svmat.tec Corporauon All royhts reserved

Solaris Only: Troubleshooting the Boot Process

Note: The boot process troubleshooting labs vary by platform due to the way inwhich the boot disk is handled by the operating system. This lab sectionapplies to Solaris only. Labs for IIP-UX arc presented in the next section.

'ote: These labs require console access. If yo II are working in a Virtual Academylab environment with no console access, you cannot perform these labs.

Troubleshooting the Boot Process - Solaris

Overview

Your goal is to recover from the problem as described in each scenario. Use yourknowledge of VxVM administration. as well as the VxVM recovery 100is andconcepts described in the lesson, to determine what steps to take to ensurerecovery. You succeed when you solve the problem with the boot disk and boot tomultiuser mode.

For most of the recovery problems. you can use any of the VxVM interfaces: thecommand line interface, the VERITAS Enterprise Administrator (VEA) graphicaluser interface, or the vxdiskadm menu interface. Lab solutions are provided foronly one method. If you have questions about recovery using interfaces notcovered in the solutions. see your instructor.

Setup

In this lab, the automated lab scripts prompt you to reboot the system. If the rebootfails, ask your instructor how to bring the system down.

I f your system is set to use enclosure-based naming. then you must turn offenclosure-based naming before running the lab scripts.

2 These labs require the system disk to be encapsulated. If your system disk isnot encapsulated. you must encapsulate it before proceeding with this lab. Usevxdiskadm to encapsulate the boot disk. Use systemdg as the name of yourboot disk group and use root d i. sk as the name of your boot disk.

3 You must have at least one additional disk that is the same size (or larger) asyour bout disk. You arc instructed to create a mirror of the boot disk in thesecond exercise.


Lab 4: Troubleshooting the Boot Process A--37

Copynqnt 'r; l006 Symanter Corporaunn. All nqtus reserved

Recovering from Encapsulated, Unmirrored Boot Disk Failure

In this lab exercise, you attempt to recover from encapsulated. unmirrorcd bootdisk failure. You succeed" hen yOU recover the system disk and boot to multiusermode. The lab script run_root simulates a boot disk failure. Ask your instructorIor the location or the run_root script.

This lab requires that the system disk is encapsulated, but not mirrored. I r yoursystem disk is mirrored. then remove the mirror.

2 Save a copy ofthe /etc/system file to /etc/system.preencap. In thenew rile (/ etc/ system. preencap), comment out the non-force loadlines related to YxYM (the lines that define the disk to be an encapsulateddevice).

3 From the directory that contains the lab scripts, run the script run_root. andselect option I, "Encapsulated. unmirrorcd boot disk failure":

Before You Begin: Ensure that the environment variable DG is set to the nameor the bootdg disk group.

4 Follow the instructions in the lab script window. This script causes the onlyplcx in root vol to change to the STALE state. When you arc ready. thesystem will be rebooted twice. Wait until the system reboot rails because or theSTALE plcx and you an: presented with the OK prompt.

5 Recover the volume root vol by using the / etc/ system. preencap filethat you created before the Iai lure. You succeed when the system boots up tomultiuser mode.


COf))'nqhi iC..' 2006 Svmantec Corporaton All 'Ignis reserved

Recovering from Encapsulated, Mirrored Boot Disk Failure (1)

In this lab exercise. you attempt to recover from encapsulated, mirrored boot diskfailure. You succeed when you recover the system disk and boot to multiusermode. The lab script run_root simulates a bout disk failure. Ask your instructorfor the location of the run_root script.

Important: Mirror the boot disk. This lab requires that the system disk isencapsulated and mirrored. If your system disk is not currently mirrored. thenmirror the system disk before continuing.

Note: Make sure that the use -nvramrc? eeprom parameter is set to truewhen you mirror the system disk. so that the device alias created by VxVM forthe mirror disk can be used.

2 If you have not already done so. save a copy of the jete/system file to/ etc/ system. preeneap. In the new file (/ ete/ system. preeneap).comment out the non-foreeload lines related to VxVM (the lines that definethe disk to be an encapsulated device).

3 From the directory that contains the lab scripts. run the script run_root. andselect option 2. "Encapsulated. mirrored boot disk failure - I":

Befure You Begin: Ensure that the environment variable DG is set to the nameof the bootdg disk group.

4 Follow the instructions in the lab script window. This script causes both plcxcsin root vol to change to the STALE state. When you are ready. the system isrebooted. The system does not come up due to the STALE plex.

5 Recover the volume root vol by using the / ete/ system. preeneap filethat you created before the failure. You succeed when the system boots up tomultiuser mode.

Lab 4: Troubleshooting the Boot Process A-39Coryrrg~ll ,to 20U6 Symantec Corpo-auon. All nqhts reservet

Optional Lab Exercises: Solaris OnlyThe next set of lab exercises is optional and may be performed if you have time.These exercises provide additional recovery scenarios for troubleshooting the bootprocess on Solaris.

Optionallab: Recovering from Encapsulated, Mirrored Boot DiskFailure (2)

In this lab exercise, you attempt to recover fi'OI11encapsulated, mirrored boot diskfailure. You succeed when you recover the system disk and boot to multiusermode. The lab script run_root simulates a boot disk failure, Ask your instructorfor the location of the run_root script.

Important: .Vlirrur the buot disk. This lab requires that the system disk isencapsulated and mirrored. If your system disk is not currently mirrored, thenmirror the system disk before continuing. If your system disk is alreadymirrored, ensure that allthc plcxcs ofthc system disk volumes and the volumesthemselves arc in ENABLED' ACTIVE stare. that is there are nosynchronization processes that arc running on the volumes on the system disk.

Note: Makc sun; that the use -nvramrc? eeprom parameter is set to truewhen you mirror the system disk. so thatthc device alias created by Vx VM forthe minor disk can be used. Run the eeprom command and view the settingstor deval ias. such as vx- al tboot and vx- rootdisJ.:.

2 Ifyou have not already done so. save a copy ofthe jete/system file to/ ete/ system. preeneap. In the new tile (/ ete/ system. preeneap).comment out the non-force load lines related to VxVM (the lines that definethe disk to be an encapsulated device).

3 From the directory that contains the lab scripts, run thc script run_root. andselect option 3. "Encapsulated. mirrored boot disk failure - 2":

Before You Begin: Ensure that thc environment variable DG is set to the nameor the bootdg disk group.

4 Follow the instructions in the lab script window. This script causes one of theplcxcs in rootvol tu change to the STALE state. The clean plcx is missing the/kernel directory. so you cannot boot up the system without recovery. Whenyou arc ready. the script reboots the system.

5 Recover the volume rootvol by using the / etc/ system. preencap filethat you created before the tuilurc. You succeed when the system boots up tomultiuser mode.

A-AD VERITAS Storage Foundation 5.0 for UNIX. Maintenance

Copvnqht " 2ll1l6 Svmantec Corporancn All r'gilts reserved

HP-UX Only: Troubleshooting the Boot Process

Note: The boot process troubleshooting labs vary by platform due to the way inwhich the hoot disk is handled by the operating system. This lab sectionapplies to IIP-UX only. Labs for Solaris are presented in the previoussection.

Note: These labs require console access. If you are working in a Virtual Academylab environment with no console access. you cannot perform these labs.

Troubleshooting the Boot Process - HP-UX

Note: Before starting this lab. ensure that the system disk is under VxVM controland that there is an alternate LVM boot disk.

Part IReboot your system using shutdown - ry now and interrupt the automaticboot process.


3 When the system is up, verify that the system is booted on the LVM disk byexecuting the bdf command. Ensure that the systemdg disk group that isused for the VxVM boot disk is imported on the system.

4 Stop the rootvol volume and change the state of the only plex in therootvol volume to STALE using the vxmend fix stale command.

5 Reboot your system using shutdown - ry now. Do not interrupt the bootprocess. Observe what happens.

6 Recover the VxVM boot disk using the maintenance mode boot withoutbooting off the LVM system disk.

Part IIEnsure that you arc booted off the VxVM system disk using the bdfcommand. Edit the /etc/vx/volboot tile and modify the hostid entry todummy.

Lab 4: Troubleshooting the Boot Process A--41

Copyright <t 2006 Symantec co-ooretoo All rl9hts reSRfler1

2 Reboot your system using shutdown -ry now. Do not interrupt the bootprocess. Observe what happens.

3 Recover till: YxYM boot disk using the maintenance mode boot withoutbooting offthe LYM system disk.

4 When the system comes back lip verify that you arc running on the YxYMboot disk. Destroy the LVM boot disk 011 the other internal disk to free lip theinternal disk for later labs.


Copyrlyht ,~, 2006 Syntantec Corporeuon All fights reserved

symantec.

Lab 5

Lab 5: Volume Maintenance

In this lab, you practice volume maintenanceactivities, such as changing volume layoutsand using the Storage Expert utility.Optional exercises provide additional practiceon managing VxVM tasks.

[For Lab Exercises, see Appendix A.--"or Lab Solutions, see Appendix B.

Lab 5: Volume MaintenanceIn this lab. you practice volume maintenance activities. such as changing volumelayouts and using the Storage Expert utility. Optional exercises provide additionalpractice on managing Vx VM tasks.

TIl\: 1;lh S\llllli\l;js 1,,[ Ihi, I:rb alc,' :uc'a:r:ti on the t(lll(min!, page"

"1.;iI) < 'inIUli"IlS: \'UIUllH' \L.il1l,·n'IIKl'," pi!g\' 1\..6'

Prerequisite Setup

To perform this lab. you need a lab system with Storage Foundation pre-installed.configured and licensed. In addition to this, you also need at least lour disks to beused in a disk group.

Copynqtu c' 2006 Symantec Corpora lion Ali nqrns reserved

A-43Lab 5: Volume Maintenance


In preparation lor this lab, you will need the following information about your labenvironment. For your reference, you may record the information here, ur referback tu the first lab in the SF Fundamentals section where you initiallydocumented this information.


~ost name trainl

I\ly Data Disks: Soluris: clt#dO -clt#d5HP-LX:c4tOdO -

c4tOd5AIX: hdisk21-hdisk26Linux: sda - sdf

VERITAS Storage Foundation 5.0 for UNIX: MaintenanceA-44Cupyngt)\ ~ 20U6 Syrnaruec Corpor anou All !lgrlls reserved


You can use either the VEA interface or the command line interface, whicheveryou prefer. The solutions tor both methods are covered where appropriate. If youuse object names other than the ones provided, substitute the names accordingly inthe commands.

Note: If you are using VEA, view the properties of the related task after each stepto view the underlying command that was issued.

Create a disk group called namedg with four disks.

2 Create a 20-MB concatenated mirrored volume called namevol1. Create aVcritas tile system on the volume and mount it to /name1. If you use VEA tocreate and mount the file system. ensure that the tile system is not added to thefile system table.=

3 Add data to the volume and verify that the tile has been added.

4 Change the volume layout from its current layout (mirrored) to a non layeredmirror-stripe with two columns and a stripe unit size of 128 sectors (64K).Monitor the progress of the relayout operation. and display the volume layoutafter each command that you run.

5 Verify that the file is still accessible.

6 Unmount the file system on the volume and remove the volume.

Using the Storage Expert Utility

Add the directory containing the StorageExpert rules to your PATI Ienvironment variable in your. prof ile tile.

2 Display a description of Storage Expert nile vxse_drll. What does this ruledo"

3 Docs Storage Expert nile vxse _drll have any uscr-sertablc parameters'

4 From the command line. create a I00-I\1R mirrored volume with no log callednamevoll in the namedg disk group. Create a tile system on the volume andmount it to / name 1.

Lab 5: Volume Maintenance A-45Copyright ,~, 2U06 Svmantec Corporation 1\11fights reserved

5 Run Storage Expert rule vxse_drll on the disk group containing the volume.What docs Storage Expert report?

6 Expand the volume to a si/c or I G13.

7 Run Storage Expert rule vxse_drll again on tile disk group containing thevolume. What docs Storage Expert report"

8 AdJ a log to the volume.

9 Run Storage Expert rule vxse_drll again on the disk group containing thevolume. What docs Storage !::xpert report'!

10 What arc thc attributes and parameters that Storage Expert uses in running thevxse drll rule"

11 Shrink the volume to IO(J M13and remove the log.

12 Run Storage Expert rule vxse_drll again. When running the rule, specifythat you want Storage Expert to test the mirrored volume against amirror_thrcshold or I ()OM13. What does Storage Expert report'

13 Unmount the file system and remove the volume used in this exercise.


Optional Lab ExercisesThe next set of lab exercises is optional and may be performed iI'you have time.These exercises provide additional practice on monitoring tasks.

Optional Lab: Monitoring Tasks

In this optional lab, you track volume relayout processes using the vxt askcommand and recover from a vxrelayout crash by using VEA or from thecommand line.

To begin. you should have at least four disks in the disk group that you arc using.

Create a mirror-stripe volume called namevoll in the namedg disk group,with a size of I GB using the vxassist command. Assign a task tag to thetask and run the vxassist command in the background.

2 View the progress of the task

3 Slow down the task progress rate to insert an I/O delay of 100 milliseconds.

View the layout of the volume in the VEl'. interface.

4 After the volume has been created, use vxassist to rclayout the volume tostripe-mirror, Use a stripe unit size of 251lK, use two columns, and assign theprocess to the above task tag.

5 In another terminal window, abort the task to simulate a crash during relayout.

View the layout of the volume in the VEA interface.

6 Reverse the relayour operation. View the layout of the volume after thereversal of the relayout operation completes. Notice that the stripe unit size isback to the original value but the layout is layered. Change the layout to non-layered.


Lab 5: Volume Maintenance A-47Copyright ~\ 2006 Syrnantsc Corporation All notus reserved


Cupynyht 2()06 Svmantec COII){lrallon All flgtlls reserved

Lab 6

Lab 6: Performance MonitoringIn this lab, you analyze Volume Manager 1/0operations using the vxstat and the vxtraceutilities.

For Lab Exercises, see Append~lFor Lab Solutions, see Append~

Lab 6: Performance Monitoring

symantec.

The purpose of this lab is to analyze Volume Manager 1/0 operations using thevxstat and the vxtrace utilities.

The lnb Solution-, I,ll lili, lab arc IO,:;lkd 011 the lulll\\\ illg page:

"1.:11.1 (, :)01 II!I\I 11,;: Pcrtormancc \11lnill1Illlg," page B· 75

Prerequisite Setup

To perform this lab, you need a lab system with Storage Foundation pre-installed,configured and licensed. In addition to this, you also need at least six disks to beused in a disk group.

Copvnqbt <&" 200b Symarnec Corporaton All nqtus reservec

A-49Lab 6: Performance Monitoring


In preparation fur this lab, you will need the following information about your labenvironment. Fur your reference, you may record the information here, or referback tu the first lab in the SF Fundamentals section where you initiallydocumented this inforrnauon.

Note: On the HP-UX platform, if you have moved the bout disk from an L VMdisk to a VxVM disk during Encapsulation and Rootability lab (lab 3) ur theTroubleshooting the Boot Process lab (lab 4), your bout disk and second internaldisk values will have changed from previous labs. l Iyou have skipped these labs,the values will still be the same. Ensure that you enter the correct values in thefollowing table,

Object SampleYaille Your Valueroot password veritas

Host name trainl

1\1) Boot Disk: Solaris:cOt OdOHI'-UX: cltl5dOIIIX: hdiskOLinux: hda

2nd Internal Disk: Soluris:cOt2dOIll'-LX: c3t15dOAIX: hdiskll.inux: hdb

I\ly nata Disks: Solaris:clt#dO -clt#d5HI'-LX: c4tOdO -c4tOd5IIIX:hdisk21-hdisk26Linux: sda - sdf

Location of Lab Scripts /student/labs/sf/(if any): sf50

Location of the fp /student/labs/sf/program: sf50/bin


Copyflghl' 21)(}6 Symanter Corpo-atco. 1\11 fights reserve»

Preparing the Environment for the Performance Labs

If the second internal disk on your system is used in the systemdg disk group.which is the disk group used for the system disk encapsulation. use the followingsteps to free it up for performance testing.

If you do not have a second internal disk or if you cannot use the second internaldisk. skip this section.

1 If the system disk is encapsulated and mirrored to the second internal disk.remove the mirrors on the second internal disk for all system disk volumes.

2 Remove the second internal disk from the systemdg disk group.

Note: If you are working on the IIP-UX platform and the second internal disk isconfigured as an alternative LVM boot disk. ensure that you are booted off theVxVM boot disk and destroy the LVM boot disk using the following command:

vxdestroy_lvmroot -v c#t#d#

where c#t #d# is the second internal disk used as an alternative LVM boot disk.

Exploring the vxs ta t Utility

In this exercise. you analyze the performance ofa disk in the testdg disk groupfor 32K random reads. You use the fp program to generate an 1:0 load. Ask yourinstructor for the location ofthc fp program.

Create a non-CDS disk group named testdg that contains one disk. If yoursystem has l\VO internal disks and the second internal disk is available for youto use. use thc second internal disk, otherwise use any disk except for yourboot disk. Name the disk testdgOl.

Note: In a North American Mobile Academy lab environment. you cannot usethe second internal disk during the labs even if the system has a second internaldisk.

2 Determine the maximum volume size that can be created using the singledrive. Create a volume named test in the testdg disk group that is themaximum size on the single drive.

3 Invoke the vxstat command to begin drive analysis on the test volume. Setthe vxstat interval to display statistics every I second. Statistics will beginprinting every second. and all statistics are displayed as () until you beginsending I/O to the volume.

Lab 6: Performance Monitoring A-51Copyright 1'.;:006 Svrnante- Corporation. 1\11r.qtus r"serveo

Note: To be able 10 analyze the output later, you can direct it to a file, forexample /tmp/vxstat, out.

4 In a different terminal window, change to the directory that contains the fpprogram,

Note: Make sure that you arc using the correct version of the fp program foryour platform, lor example, fp _sun for Solaris, fp _hp for HP-UX, orfp_linux lor Linux ..Display a description of the fp program by running the fp command withoutany parameters:

5 From the directory that contains the fp I/O program, start several invocationsofthe fp program by using the command:

Note: Alternatively, you can use the v i editor to createa simple script thatcontains ten or more invocations of this fp command. This method can moreeffectively flood the volume with I/O:

a Invoke the vi editor and create a tile named /tmp/testscript.

b Copy the fp command shown above into the file ten or more times.

c Save the testscript tile.

d Change the permissions on the Iilc 10 he readable and writable by the rootuser.

e Run the test script.

6 When you execute the fp command or your test script, the vxstat output inthe other terminal window begins to display data. Wait fur all the fpcommands or the script to finish executing, then stop the vxstat output bytyping CTRL-C on the terminal you arc running vxs t a t .and analyze thevxstat output and determine the peak performance of the drive.

7 Destroy the testdg disk group.


CopYflghl 02006 Svmautec Corporation All flYtVs teserveo

Optional Lab ExercisesThe next set of lab exercises is optional and may be performed if you have time.These exercises provide additional performance scenarios for exploringperformance utilities.

Optional Lab: Analyzing Drive Performance: Scenarios

In this exercise, you analyze drive performance based on sample vxstat outputand identify possible improvements to volume layouts. This exercise is theoretical.but designed to help you understand how to interpret vxstat output.

Note: The samples provided arc from a Solaris platform. Therefore I block isequivalent to 512 bytes.

Scenario I

Suppose that you have a disk group named testdg that contains four disks. Youhave a IOO-MB volume. called test. striped across two disks with a stripe unitsize of 4 M B. There are three processes performing random reads that arc 512K insize on the volume. There are no other volumes in the disk group.

When you run a performance test and run vxstat on the disk group. thefollowing output is displayed:

Analyze the vxstat output. What do you notice?

What changes might you make to the volume layout to improve performance')

Scenario 2

Suppose that you have a disk group named testdg that contains four disks. Youhave a IOO-MB volume, called test. that is concatenated using two disks. Thereare three processes performing random reads of size .'i 12K on the volume. Thereare no other volumes in the disk group.

When you run a performance test and run vxstat on the disk group. thefollowing output is displayed:

Analyze the vxsta t output. What do you notice')

2 What changes might you make to the volume layout to improve performance')

Lab 6: Performance Monitoring A-53Cocynum E ;ton6 Symantec Corporation All nahts reserved

Scenarin 3

Suppose that you have a disk group named testdg that contains lour disks. Youhave two volumes:

A IOO-MB volume: called test striped across three disks with a stripe unitsize:of4 MB

Another IOO-MB volume called test2 with a concatenated layout on the:disktestdgOl, which is also one of the disks usedby the volume test.

There arc three processes performing random reads of size 128K on the testvolume andone process performing random reads of size 512K 011 the test2volume.

Whenyou rUII a performance test andrun vxstat on the disk group, thefollowing output is displayed:

vxstat -g testdg -d

OPERATIONS BLOCKS AVG TIME (ms)TYP NAME READ WRITE READ WRITE READ WRITEdm testdg01 241 a 138496 a 30.8 0.0dm testdg02 126 a 32256 a 17.6 0.0dm testdg03 132 a 33792 a 18.2 0.0dm testdg04 a a a 0.0 0.0

Analyze thc vxstat output. What do you uoticc?

2 What changes might you make to the volume layout to improve performance?

vxstat -g testdg -d

OPERATIONS BLOCKS AVG TIME(ms)TYP NAME READ WRITE READ WRITE READ WRITEdm testdg01 128 a 32768 a 23.0 0.0dm testdg02 124 a 31744 a 24.3 0.0dm testdg03 147 a 37632 a 24.7 0.0dm testdg04 100 a 102400 a 25.5 0.0


Optional Lab: Analyzing the Application 1/0 Profile: Scenarios

In this exercise, you analyze the application 1/0 profile based on sample vxt raceoutput and identify possible improvements to volume layouts (for example,changing the layout from concatenated to striped. increasing the number ofcolumns, changing the stripe unit size, and so on). This exercise is theoretical. butdesigned to help you understand how to interpret vxtrace output.

Note: The samples provided are from a Solaris platform. Therefore I block isequivalent to 512 bytes."

Scenario I

Suppose that you have a disk group named testdg that contains four disks. Youhave a IOO-MBvolume, named test, striped across two disks with a stripe unitsize of 4K.

When you start a trace on the volume, run a performance test on the volume, andthen stop the trace on the volume. the following vxtrace output is displayed:

vxtrace -g testdg -d /tmp/appiolabl.out -0 dev.disk test

ICtrl+qvxtrace -g testdg -f /tmp/appiolabl.out -0 dev.disk I pg

3601 START write vdev test block 115392 len 64 concurrency 1 pid 69483602 START write disk c1t8dOs2 op 3601 block 57696 len 83603 START write disk c1t9dOs2 op 3601 block 57696 1en 83604 START write disk c1t8dOs2 op 3601 block 57704 len 83605 START write disk c1t9dOs2 op 3601 block 57704 len 83606 START write disk c1t8dOs2 op 3601 block 57712 1en 83607 START write disk c1t9dOs2 op 3601 block 57712 len 83608 START write disk c1t8dOs2 op 3601 block 57720 len 83609 START write disk c1t9dOs2 op 3601 block 57720 1en 83602 END write disk c1t8dOs2 op 3601 block 57696 len 8 time 03603 END write disk c1t9dOs2 op 3601 block 57696 len 8 time 03604 END write disk c1t8dOs2 op 3601 block 57704 len 8 time 13606 END write disk clt8dOs2 op 3601 block 57712 len 8 time 13608 END write disk clt8dOs2 op 3601 block 57720 len 8 time 13605 END write disk clt9dOs2 op 3601 block 57704 len 8 time 13607 END write disk clt9dOs2 op 3601 block 57712 len 8 time 13609 END write disk clt9dOs2 op 3601 block 57720 len 8 time 13601 END write vdev test op 3601 block 115392 len 64 time 1

Analyze the application l/O profile based on the vxtrace output. Analyze thenumber of concurrent processes, the application 110 size for each process, andwhether the process is performing random or sequential 1/0. What do younotice')

2 WhM changes might you make to the volume layout to improve performance'.'

Lab 6: Performance Monitoring A-55Copyfl~h! f: 2006 Symantec Corporation. All nqtus reserved

Scenario 2

Suppose that you have a disk group named testdg that contains four disks. Youhave a IOO-MB concatenated volume. named test. on one of the disks.

When you start a trace on the volume. run a performance test on the volume, andthen stop the trace on the volume, the following vxtrace output is displayed:

vxtrace -g testdg -d /tmp/appiolab2.out -0 dev,disk test

ICtrl+Cj

vxtrace -g testdg -f /tmp/appiolab2.out -0 dev,disk I pg

6005 START read vdev test block 108256 len 32 concurrency 2 pid 72116006 START read disk c1t8dOs2 op 6005 block 108256 len 326007 START read vdev test block 59552 len 32 concurrency 3 pid 72176008 START read disk c1t8dOs2 op 6007 block 59552 len 326004 END read disk c1t8dOs2 op 6003 block 172512 len 32 time 16003 END read vdev test op 6003 block 172512 len 32 time 16009 START read vdev test block 196352 len 32 concurrency 3 pid 72146010 START read disk c1t8dOs2 op 6009 block 196352 len 326008 END read disk c1t8dOs2 op 6007 block 59552 len 32 time 16007 END read vdev test op 6007 block 59552 len 32 time 16011 START read vdev test block 78688 len 32 concurrency 3 pid 72176012 START read disk c1t8dOs2 op 6011 block 78688 len 326010 END read disk c1t8dOs2 op 6009 block 196352 len 32 time 06009 END read vdev test op 6009 block 196352 1en 32 time 06013 START read vdev test block 151712 len 32 concurrency 3 pid 72146014 START read disk c1t8dOs2 op 6013 block 151712 len 326006 END read disk c1t8dOs2 op 6005 block 108256 len 32 time 26005 END read vdev test op 6005 block 108256 len 32 time 2

Analyze the application I/O profile based on the vxtrace output. Analyze thenumber or concurrent processes, the application I/O size for each process, andwhether the process is performing random or sequential 1/0. What do younotice'?


Scenario 3Suppose that you have a disk group named testdg that contains lour disks. Youhave a IOO-MB volume. named test. striped across three disks with a stripe unitsize of -+K.

When you start a trace on the volume. run a performance test 011 the volume, andthen stop the trace 011 the volume. the following vxtrace output is displayed:


ICtrI+CI



Cupynght i 2D()6 Symantec Corpor auon All right" reserved

6802 START read vdev test block 194304 len 64 concurrency 2 pid 74876803 START read disk c1t8dOs2 op 6802 block 64768 len 86804 START read disk c1t9dOs2 op 6802 block 64768 len 86805 START read disk c1t10dOs2 op 6802 block 64768 len 86806 START read disk c1t8dOs2 op 6802 block 64776 len 86807 START read disk c1t9dOs2 op 6802 block 64776 len 86808 START read disk c1t10dOs2 op 6802 block 64776 len 86809 START read disk c1t8dOs2 op 6802 block 64784 len 86810 START read disk c1t9dOs2 op 6802 block 64784 len 86795 END read disk c1t9dOs2 op 6793 block 67712 len 8 time 16798 END read disk clt9dOs2 op 6793 block 67720 len 8 time 16801 END read disk c1t9dOs2 op 6793 block 67728 len 8 time6794 END read disk c1t8dOs2 op 6793 block 67712 len 8 time 16797 END read disk c1t8dOs2 op 6793 block 67720 len 8 time6800 END read disk c1t8dOs2 op 6793 block 67728 len 8 time 16796 END read disk clt10dOs2 op 6793 block 67712 len 8 time6799 END read disk c1t10dOs2 op 6793 block 67720 len 8 time6793 END read vdev test op 6793 block 203136 1en 64 time 26811 START read vdev test block 169984 len 64 concurrency 2 pid 74846812 START read disk c1t10dOs2 op 6811 block 56656 len 86813 START read disk c1t8dOs2 op 6811 block 56664 len 86814 START read disk c1t9dOs2 op 6811 block 56664 len 86815 START read disk c1t10dOs2 op 6811 block 56664 len 86816 START read disk c1t8dOs2 op 6811 block 56672 len 86817 START read disk c1t9dOs2 op 6811 block 56672 len 86818 START read disk c1t10dOs2 op 6811 block 56672 len 86819 START read disk c1t8dOs2 op 6811 block 56680 len 86820 START read vdev test block 32320 len 64 concurrency 3 pid 7490

I

Analyze the application l/O profile based on the vxtrace output. Analyze thenumber of concurrent processes. the application lIO size for each process. andwhether the process is performing random or sequential 110. What do younotice')

2 What changes might you make to the volume layout to improve performance'!

Scenario 4

Suppose that you have a disk group named testdg that contains four disks. Youhave a IOO-Ml:lvolume, named test. striped across three disks with a stripe unitsize of 256K.

When you start a trace on the volume, run a performance test on the volume, andthen stop the trace on the volume. the following vxtrace output is displayed:


ICtrl+C1vxtrace -g testdg -f /tmp/appiolab4.out -0 dev,disk I pg

Lab 6: Performance Monitoring A-57Copyncbt f 2[106 Symantec Corporanor All nqtus reserved

8972 START read vdev test block 0 len 64 concurrency 1 pid 77518973 START read disk c1t8dOs2 op 8972 block 0 len 648973 END read disk c1t8dOs2 op 8972 block 0 len 64 time 28972 END read vdev test op 8972 block 0 len 64 time 28974 START read vdev test block 64 len 64 concurrency 1 pid 77518975 START read disk c1t8dOs2 op 8974 block 64 1en 648975 END read disk clt8dOs2 op 8974 block 64 len 64 time 08974 END read vdev test op 8974 block 64 len 64 time 08976 START read vdev test block 128 len 64 concurrency 1 pid 77518977 START read disk c1t8dOs2 op 8976 block 128 len 648977 END read disk c1t8dOs2 op 8976 block 128 len 64 time 08976 END read vdev test op 8976 block 128 1en 64 time 0

AnaIYL<:the application 1/0 profile based on the vxtrace output. Analyze thenumber of concurrent processes. the application 1/0 size for each process, andwhether the process is performing random or sequential 110. What do younotice'



COI'yngnt 'D 2006 Svmantec Corporauon All fights ieseivea

Optional Labs: Measuring Volume 1/0 Operations

In the following exercises, you determine whether reads or writes occur whenVxVM performs various actions.

Note: The solutions provided in this section show sample vxstat outputs from aSolaris platform. You may observe different sizes if you are working on anIIP-UXplatform. This is because on IIP-UX one sector is 1024 bytes, whereas on Solaris,one sector is 512 bytes.

Optional Lab: When Creating a Disk Group

Does VxVM write into the public region ora disk when it creates a disk group'!

Create a disk group named datadg using six disks.

2 Determine whether Vx VM writes into the public region of a disk when itcreates a disk group.

Optional Lab: When Creating a Volume

Does VxVM write into the volume, plexcs, subdisks, or disks space when it createsa volume')

Reset the read/write counters for datadg. Create a 50-Ms' concatenated(RAID-O) volume named datavoll in datadg.

Did reads or writes to the volume, plcx. subdisk. or disk occur?

2 Reset the read/write counters for dat adg. Create a 30-M B, 3-columll, striped(RAID-O) volume named datavo12 ill datadg.

Did reads or writes occur')

3 Reset the read/write counters for datadg. Create a 30-MB, 2-way, mirrored(RAID-I) volume named datavo13 in datadg.

Did reads or writes occur? Did any synchronization occur'!

4 What type of synchronization occurred between the mirrors')

5 Reset the read/write counters for datadg. Create a IOO-MB, 3 column.striped, mirrored and logged volume (RAID 0+1) named datavo14 indatadg.

Lab 6: Performance Monitoring A-59Copyright <f' 2006 Svmantec corooranoo. All noms reserved

Did reads or writes occur"

6 Why do writes occur when creating mirrors hut not when creatingconcatenated or striped volumes"

7 Reset the read/write counters tor datadg. Create a30-Ml3, 2-way mirrored. 3column striped and logged (RAID-I+O) volume named datavo16 indatadg.

Did reads or writes occur'?

Note: When a layered (stripe-mirror or RAID-I +0) volume is involved, omitthe name or the high-level volume to get the statistics.

8 Docs YxYM write into the volume. plcxcs, subdisks. or disks when it creates avolume'!

9 Reset the read/write counters tor datadg. Create a 5MB mirrored volumenamed datavol 7 and initialize it to zero. Is the volume's address spacewritten when it is initialized to zero?

Optional Lab: When Mirroring a Volume or Resynchronizing Mirrors

Docs YxYM write into the volume. plcxcs, subdisks, or disks when it mirrors avolume or rcsynchronizcs mirrors'!

Creak a 50-Ml3, concatenated (RAID-O) volume named datavo18 indatadg.

2 Reset the read/write counters lor datadg. Add a mirror to the datavo18volume.

Did reads and lor writes occur'! Docs adding a mirror perform atomic-copy orrcad-writcbuck?

3 What is the meaning or atomic copy'!

Optional Lab: When an Application Performs I/O to a Volume

Create a 500-Ml3, concatenated (RAID-O) volume named datavo19 indatadg.


Copynqnt <t: 2006 Sytuanlec Corporauon 1\11nqrus reserved

vxassist -g datadg make datavo19 SOOm

2 Reset the read/write counters for datadg, Starr JlO to the datavo19 volumeusing dd in the background, While the 110 is ongoing examine reads or writes.Kill the dd process when you are finished,

3 Assuming that there is only one process doing 110 to the disk (no parallel 110)and that there are 512 bytes per block. how would you calculate the I/Othroughput to the disk')No, of Blocks x 512/(No. of 1/0 Operations x Average 1:0 Time/\OOO) BlseeDivide by 1024 for Kfs/secDivide by 1024 for MB!sec

4 lllustratc that one 1/0 to the mirrored volume datavo18 generates two I/Oswithin the volume,

Optional Lab: When Removing a Volume

Docs VxVM write into the volume. plcxes, subdisks, or disks when it removes avolume':'

Reset the read/write counters for datadg, List the volumes in datadg,

2 Remove the datavoll volume,

3 Does VxVM write into the volume. plcxes, subdisks, or disks when it removesa volume? What docs this imply"

Optional Lab: When Removing a Plex

Does VxVM write into the volume, plexes, subdisks, or disks. when it removes aplex?

1 Reset the read/write counters for datadg, L.ist the volumes in datadg,

2 Does VxVM write into the volume, plexes. subdisks, or disks when it removesa plcx? What docs this imply"

Lab 6: Performance Monitoring A-61Copyr'Qllt :{.<'006SvmaruecCorporanon All fl9htSreserved

Optional lab: When Destroying a Disk Group

Does Yx YM write when it destroys a disk group'!

Reset the read/write counters for datadg. Destroy datadg. Did any writesoccur')

2 Docs YxYl'vJ write into the public area of the disk when any ofthe aboveoperations arc performed':' What docs this imply for administration ofvolumes!


Ccpynqhtv 2006SvmantscCo-porauon1\11fights reserved

symantcc.


For Lab Exercises, see Appendix A.For Lab Solutions, se~Appendix B.

Lab 7: Point-in-Time CopiesIn this lab. you perform off-host processing using third-mirror break-off' volumesnapshots, create space-optimized instant volume snapshots. and restore a tilesystem using storage checkpoints. Optionally. you also create and investigate full-sized instant volume snapshots.

Prerequisite Setup

To perform this lab. you need a lab system with Storage Foundation pre-installed,configured and licensed. In addition to this. you also need at least four disks to beused in a disk group.

Before starting this lab you should have all the external disks assigned to youalready initialized but free to be used in a disk group.

Copyright ,[ 200£ Syrnaruec Coroo-auoo. All rogtlls reserved

A-63Lab 7: Point-in-Time Copies


In preparation Ior this lab. you will need the following information about your labenvironment. For your reference, you may record the information here, or referback to the lirst lab in the SF Fundamentals section where you initiallydocumented this information.

Object Sample Value Your Valueruut password veritas

Host name trainl

Host name of the system train2sharing disks with mysystem1\1)'nata J)jsks: Solaris: c i t#dO -

clt#dSHP-LX:c4tOdO -

c4tOdsAIX: hdisk21-hdisk26Linux: sda - sdf

VERITAS Storage Foundation 5.0 for UNIX: MaintenanceA-64

Cccvngm ~,2()06 Svruarttec Corporation All fights reserved

Off-Host Processing Using Third Mirror Break-off Volume Snapshots

Phase I: Create, Split, and Deport1 Identify the name of the system that is sharing access to the same disks as your

system. If you are not sure, check with your instructor. Note the name of thepartner system here.Partner system hosrname: _ ----~~~------

2 On your local lab system, create a disk group called namedg with four dish.

3 Create a 500-MB concatenated volume, namevoll, using a single disk.Create a Veritas tile system on the volume and mount the tile system on themount point / name 1.

4 Add data to the tile system using the following command:

echo "Pre-snapshot for name" > /namel/presnap on name

and verify that the data has been added.

5 Enable FastResync for the volume namevoll. Can you identify what haschanged"

6 Add a mirror to the volume for use as the snapshot. Observe the volume layout.What is the state of the newly added minor after synchronization completes'!

7 Create a third mirror break-off snapshot named namesnapl using the newmirror youjust added. Use the vxsnap ~g namedg list command toobserve the snapshots in the disk group. Can you find similar information inthe VEA GUI"

8 Split the snapshot volume into a separate disk group from the original diskgroup called nameOHPdg:

9 Verify that the nameOHPdg disk group exists and contains namesnapl.First, display the disk groups on the system. You should see the newnameOHPdg disk group displayed. Then, view the volume information for thenameOHPdg disk group.

10 Deport the disk group that contains the snapshot volume. If you have a partnersystem that shares access to the external disks with your system, you can usethe new host information using the hosrname of the partner system.

11 View the disk groups 011 the system.

Lab 7: Point-in-Time Copies A-65Copyright ·F· 2006 Svmantec Corpcrenon All rlQhts -eservec

Run the vxdisk command to view the status otihc disks on the system.Alternatively, you can view till: status of the disks in V EA

12 Add additional data to the original volume using the following command:

echo "Post-snapshot for name" > \/namel/postsnap on name


Phase 2: Import, Process, and Deport13 Remote login to the partner system which will be used as the off-host

processing (UHP) system.

Notes:

I I' you are working on a standalone system, skip this step and use your ownsystem as the partner system.

I I' you want to continue using the graphical user interface (VEA) on thepartner system. you need to conned to the partner system using the V EAclient on yuur local system.

14 On the oft-host processing (OHP) host (your partner system) where the backupor processing is to be performed, import the disk gruup that contains thesnapshot volume.Note: You may need to rcscun the disks using the vxdctl enablecommand on the 01--1I' host so that the host detects the changes.

View the status or the volume in the nameOHPdg disk group.

15 To perform off-host processing, you must first start the volume and mount thefile system on the off-host processing host. Use the mount point/namesnapl.

16 View and compare the contents of both file systems,

17 Check if you can write to the snapshot file system during off-host processingby creating a new tile in the snuphsot file system as follows:

echo "Data in snapshot of name" > \/namesnapl/data_on_namesnapl

18 Alter completing off-host processing, you arc ready to reattach the snapshotvolume with the original volume. UII1l10unt the snapshot volume on the off-host processing host.


Cop)'''glil ~,2006 Svmanter: Comoeauon All "yh!s reserved

Note: If you have been using your local lab system as the OIIP host. you do notneed to perform the next three steps ( 19-21 ). However, in an actual off-hostprocessing situation, you would perform these steps.

19 On the OIlP host. deport the disk group that contains the snapshot volume.

20 If you had been working on a partner system, exit from the partner system.Alternatively, if you had been using the VEA, disconnect from the partnersystem.

Phase 3: Import, Join, and Resynchronize

21 On the primary host (your local lab system), reimport the disk group thatcontains the snapshot volume:

22 Rejoin the disk group that contains the snapshot volume to the disk group thatcontains the original volume.

23 At this point you should have the original volume and its snapshot in the samedisk group but as separate volumes. There is still no synchronization betweenthe original volume and the snapshot volume. To observe this, the snapshotvolume will be mounted again to observe its contents. You would not need toperform this step during a normal ofT-host processing procedure. Note that ifyou have been using the CLI, the snapshot volume is initially disabledfollowing the join.

a Restart the snapshot volume if necessary.

b If necessary, run a file system check on the snapshot volume. Note that thisstep should not be necessary if you have cleanly unmounted the file systembefore the deport on the OHP host.

c Mount namesnapl back on the /namesnaplmount point. Create themount point ifnecessary.

d View and compare the contents of both file systems.

e Unmount the / namesnapl tile system.

24 On the primary host (your local lab system), reattach the pie xes of the snapshotvolume to the original volume and resynchronize their contents.

25 Remove the snapshot mirror.

Lab 7: Poinl-in-Time Copies A-67Copyright 'c 2(1[)6Symantec Comoranon Ali r1gh1S fflS8rVfJd

Using Space-Optimized Instant Volume Snapshots

Select a disk in the namedgdisk group that is not used by the original volumenamevo11, and create a 50-MI3volume on this disk to be used as the cachevolume. Name the cache volume namecachevol. Create a cache objectcalled namecache on the cache volume. Ensure that the cache object isstarted,

Note: l lyou use the YEA to create the cache object. the autogrow optionwill be left at the default value of off. If you use the command line you canchange this setting to on while creating the cache object.

2 Observe how the cache object and the cache volume is displayed in the diskgroup.

3 Verify that the namevo11 volume is already prepared for instant snapshotoperations by displaying information about the DCO log.

4 Add data to the / name1 file system using the following command:

echo "New data before 8081 for name" > \/name1/presos1_on_name1

and veri Iy that the data is written.

5 Create a space-optimized instant snapshot of the namevo11 volume, namednamesos1, using the cache object namecache.

6 Display information about the snapshot volumes using the YEA, or thevxprint, vxsnap list and vxsnap print commands from thecommand line.

7 Using the command line. veri Iy which snapshots arc associated to the cacheobject.

8 Mount the space optimized snapshot volume namesos1 to the /namesos1directory.

9 Observe the contents of the / namesos 1 directory and compare it to thecontents of the / name1directory.

10 Add data to the /name1 file system using the following command:

echo "New data before 8081 for name" > \/name1/presos1_on_name1

and verily that the data is written.

VERITAS Storage Foundation 5.0 for UNIX" MaintenanceA-68COPY'Iljllt ~. 2006 Svma-uec Corpori1tlWl All nqrus reserved

11 Create a second space-optimized instant snapshot of the namevoll volume,named namesos2, using the same cache object narnecache.

12 Using the command line, verify which snapshots are associated to the cacheobject.

13 Mount the space optimized snapshot volume namesos2 to the /narnesos2directory.

14 Observe the contents of the original file system and the two space optimizedsnapshots.

15 Make the following changes on the tile systems:

a Remove the data you had on the original tile system prior to starting theUsing Space-Optimized Instant Volume Snapshots section. If you havefollowed the lab steps, you need to remove the pre snap on_nameandpostsnap_on_narne files from the /namel file system.

b Add new data to the space optimized snapshot volumes using the followingcommands:

16 Observe the contents of the original tile system and the two space optimizedsnapshots.

17 Assume that you have decided to use the contents of the second spaceoptimized snapshot as the final version of the original file system. Restore theoriginal tile system using the second space optimized snapshot. Note that youwill have to unmounr the original file system to make this change. Mount theoriginal file system back to / narnel directory when the restore operationcompletes.


19 Refresh the first space optimized snapshot. narnesosl. Note that you willneed to unrnount the first space optimized snapshot to make this change.Mount the namesosl volume again after its contents are refreshed.


Lab 7: Point-in-Time Copies A-59COPYright t. 200ti Svmaruec Corporation All nqtus reserved

21 LJnmount the two space optimized snapshots and dissociate them from theoriginal volume.

22 Remove the space optimized snapshot volumes.

Note: l lyou want to use the vxassist remove volume command todelete the volume from the command line, you first need to delete the DCOlog. Alternatively you can use the vxedi t -g diskgroup - r f rmvolume_namecommand to remove the volume together with the associatedDtO log.

23 Remove the cache object with its associated cache volume.

24 Unmount the / name1 file system and remove the original volume,namevoll.

Note: llyou want to use the vxassist remove volume command todelete the volume from the command line. you lirst need to delete the DCOlog. Ahcrnativcly you can use the vxedit -g diskgroup -rf rmvol ume_namecommand to remove the volume together with the associatedDCO log.

VERITAS Storage Foundation 5.0 for UNIX: MaintenanceA-70Ccpvnqnt 'I." 21106 Symantec COqlOI auon 1\11rights reserved

Restoring a File System Using Storage Checkpoints

In the beginning of this section you should have a namedg disk group with fourunused disks in it.

Create a simple 1500m volume called origvol in the namedg disk group.

2 Create a VxFS file system on the volume,

3 Make three new mount points: lor ig, I checkpt 1, and I checkpt 2.

4 Mount the file system on lorig.

5 Write a file of size I M named 4pm in the original file system.

6 Create a storage checkpoint named thu_5pm 011 lorig. Note the output.

7 Mount the thu _ 5pm storage checkpoint on the mount point I checkpt l.

8 Write some more files in the original file system on lorig, and synchronizethe tile system using the following commands:

dd if=/dev/zero of=/orig!5pm bs=1024k count=5dd if=/dev/zero of=/orig/5pm_2 bs=1024k count=5sync; sync

9 Create a second storage checkpoint. called thu_6pm, on lorig. Note theoutput.

10 Mount the second storage checkpoint on the mount point / checkpt2.

11 Write some more files in the original tile system on lod g, and synchronizethe tile system using the following commands:

dd if=/dev/zero of=/orig/6pm bs=1024k count=6dd if=/dev/zero of=/orig/6pm 2 bs=1024k count=6sync; sync

12 View the checkpoints and the original file system.

13 To prepare to restore from a checkpoint. unmount the original tile system andboth storage checkpoints.

14 Restore the tile system to the thu _ 6pm storage checkpoint.

15 Run the fsckpt_restore command again. Note the output.

Lab 7: Point-in-Time Copies A-71Coovnqrn 't 2006 Symantec Corpo.auon. All fights reserved



Copvnqru ,~ 200ti Svrnanrec Corporation All fights reserved

Optional Lab ExercisesThe next set of lab exercises is optional and may be performed if you have time.These exercises provide additional practice in exploring storage checkpoints.

Optional Lab: Storage Checkpoint Behavior

In this exercise, you perform and analyze tour types offile system operations:

A file to be deleted (lk. to delete)

A tilt: to he replaced by (new) content (lk. to replace)

A file to he enlarged (lk5 . to_append)

A tile to be written by databases (10m.db I o: the tile remains at the sameposition with the same size. but some blocks within it are replaced)

Create a disk group named xdg with four disks.

2 Create a 12H-MB mirrored volume with a log. Name the volume xvol. Mountthe volume at /xvol.

3 Add these four new files to the volume and view the tiles:

1K named /xvol/1k.to delete

1K named /xvol/1k.to_replace

3B=1536bytes named /xvol/1k5.to append

10M named /xvol/10m.db_io

4 Remount /xvol and run ncheck.

5 Create a storage checkpoint for /xvol named CKPT.

6 Delete the file 1k. to delete.

7 Create a new IK tile named 1k. to replace

8 Copy the 1k5. to_append tile to /tmp.

9 Add the 1k5. to append file in /tmp to the original 1k5. to appendtile in /xvol. - -

10 Use the following Perl command 10 generate database-like 1'0 (modifying ablock within a database file).

The second line opens read/write access to the tile without recreating it orsimply appending new data.

Lab 7: Point-in-Time Copies

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A-73

The third line creates a variable containing 8K "x".The next line positions the tile pointer at 80K offset from the beginning ofthe lile,The following line writes at this position the new 8K block.

perl -e '

> openIFH,"+< /xvol/10m.db_io") I I die;> $Block="x" x 8192;.> sysseek IFf!, 8192, 0);> syswlite IFH, $Block, 8192, OJ;.> c1oseIFH);'

11 Remount /xvol and run /ncheck.

Examination of Storage Checkpoint Behavior

The following information is an analysis of the previous output from ncheck:• lk. to delete

Same data blocks (2768-276'.1)mapped to CKPT.

• lk. to replaceOld data blocks (4 I44-4 I45) mapped. not copied, to CKPT. New data blocks(24336-24337) were written to a new location.

• lk5. to_append13cforechcckpointingUNNAMED

12784 2785 12786 12787

Alter chcckpoinring and appending dataUNNAMED

12784 12785 12786 2787 124062 24063

CKPT

12784 12785 14146 14147

To get the UNNAMEDfile system. which is normally the active one. ascontiguous as possible, a copy-before-write of the middle block is performed.Otherwise copy-before-write would be unnecessary in favor of simple addressmapping.Note: Blocks 2784-2785 are mapped to both UNNAMEDand CKPT. This is notshown in the output ofncheck.


Copynqht (9 2006 Svrnantec Cotp •.-irauon All r'ghls reserved

• 10m.db ioThe data file for UNNAMEDremains at the same position (2!WO-2!WI. 4352-2406 I, 2R I 6-3583).

Note: These files are fragmented because the required space was notpreallocaied in one extent.

The new blocks are written to UNNAMED.and therefore the old data must becopied to 24352-243(,7 n~K) before the new blocks arc writteu. Otherwisecopy-before-write would be unnecessary in favor of simple address mapping.Note: In all cases, inode and directory information is copied before the write.

12 Unmount the checkpoint and the original tile system. Destroy the xdg diskgroup.

Lab 7: Point-in-Time Copies

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COD}r:ght.0 2006 Syn);lnlec Corooranon 1\11fights reserver

Appendix B

Lab Solutions

Education and SRT FrameMaker Template SetB-2Copyright ~ 20nS Svmautec Corporation All nqtus reserved

Lab 1


!For Lab Exercises, see Appendix A.l£()r Lab Solutions, see Appendix B.

symantec.

Lab 1 Solutions: Maintaining Data ConsistencyIn this lab. you practice recovering from a variety of piex problem scenarios. andoptionally, observe the benefits of a dirty region log during a system crash. Toinvestigate and practice recovery techniques, you will use a set of interactive labscripts. Each script:

Sets lip the required volumesSimulates and describes a failure scenarioPrompts you to fix the problem

The Lab Exercises for this lab are located on the following page:

Prerequisite Setup

To perform this lab. you need a lab system with Storage Foundation pre-installed.configured and licensed. In addition to this. you also need a minimum of threeexternal disks to be used during the labs.

Copynqht f 2006 Syrnantec Corporation All nqtus reserved

B-3Lab 1 Solutions: Maintaining Data Consistency


In preparation Ior this lab, you will need the following information about your labenvironment. For your reference, you may record the information here, or referback to the first lab in the SF Fuudamcntals section where you initiallydocumented this information.

Object Sample Value Your Value~Iy Data Disks: Solar is: clt#dO -

clt#d5HP-LX: c4tOdO -c4tOd5/\IX: hdisk21-hdisk26Linux: sda - sdf

Location fir Lab Scripts: /student/labs/sf/sf50


Copyfl\jhl i;': 2006 Svmantec Corporation All nqhts reserved

Preparation for Plex Recovery Labs

Overview

Your goal is to recover from the problem as described in each scenario. Use yourknowledge ofVxVM administration. as well as the VxVM recovery tools andconcepts described in the lesson. to determine what steps to take to ensurerecovery. Alter you recover the test volumes. the script verifies your solution andprovides you with the result. You succeed when you recover the volumes withoutcorrupting the data.

For most of the recovery problems. you can use any of the VxVM interfaces: thecommand line interface. the VERITAS Enterprise Administrator (VEA) graphicaluser interface. or the vxdiskadm menu interlace. Lab solutions are provided foronly one method. I f you have questions about recovery using interfaces notcovered in the solutions. see your instructor.

SetupDue to the way in which the lab scripts work. it is important to set lip yourenvironment as described in this setup section:

If your system is set to use enclosure-based naming. then you must turn offenclosure-based naming before running the lab scripts.

2 I f you have a namedg disk group left from previous labs. ensure that the diskgroup has no mounted file systems or volumes. lf nccessary, unmounr anymounted file systems that are on volumes in the namedg disk group andremove the volumes.

If necessary:umount /mount_pointvxassist -g namedg remove volume volume name

3 If you have not already done so. create a disk group named testdg and addthree disks (preferably of the same size) to the disk group. Assign thefollowing disk media names to the disks: testdgOl. testdg02, andtestdg03.

If necessary:vxdisksetup -i device_tagvxdg init testdg testdgOl=device_tagl \

testdg02=device_tag2 testdg03=device_tag3Note: If you do not have enough disks. you can destroy disk groups created inother labs (for example, namedg) in order to create the testdg disk group.

Lab 1 Sotutions: Maintaining Data Consistency B-5Copyroghl 'f 2005 Syrnantar Corpoear.on All nqnts reserved

4 Before running the automated lab scripts, set the DG environment variable inyour root profile to the name of the test disk group that you arc using:

Snlarls, vi /,profileHP-UX DG=testdg; export DG

Linux vi /root/.bashrcDG=testdg; export DG

Rerun your profile by logging out and logging back on. or manually running it.

5 Ask your instructor fur the location of the lab scripts.

Resolving Plex Problems: Temporary Failure

In this lab exercise, a temporary disk failure is simulated. By using the vxmendcommand. you must select the plcx that has the correct data and recover thevolume by using the clean plcx. I I'you select the wrong plcx as the dean plcx, thenyou have corrupted the data. The lab script run_states sets up the test volumeconfiguration. simulates a disk failure. and validates your solution for recoveringthe volume. Ask your instructor lor the location of the run_states script.

Before You Begin: Check to ensure that the environment variable DG is set to thename of the testdg disk group:echo $DG

If it is not set, set it before you continue:

DG="testdg"export DG

From the directory that contains the lab scripts, run the script run_states.and select option I, "Turned 011'drive (temporary failure)":./run_states1) Lab 1 - Turned off drive (temporary failure)2) Lab 2 - Power failed drive (permanent failure)3) Lab 3 - Unknown failure4) Optional Lab 4 - Turned off drive with layeredvolume5) Optional Lab 5 - Power failed drive with layeredvolumex ) ExitYour Choice? 1

B-6 VERITAS Storage Foundation 5.0 for UNIX: Maintenance

CopynqhtI 20()6Sv.uaruec Corporancn All rights rasarvsc


Note: If you receive an error message about the /image file system becomingfull during volume setup. ignore the error message. This error will not haveany impact on further lab steps or lab resuits.

2 Read the instructions in the lab script window. The script simulates a diskpower-off by saving and overwriting the private region on the drive that is usedby the volume. Then. when you are ready to power the disk back on. the scriptrestores the private region as it was before the failure


Assume that the drive that was turned off and then hack on was c 1 t2dOfor a Solaris or HP-UX system or sdb for a Linux system (with the plextest-Ol) (actual device name will vary by system). The plex test-02 wasSTALE prior to the failure of the disk with the plex tes t - 0 1. When thedisk is powered back on and reattached, the plex test-Ol continues tocontain the most up-to-date data.

Note: When performing recovery procedures, run vxprint and vxdisklist often to see what is changing after issuing recover)' commands:

vxprint -g testdg -htrvxdisk -0 alldgs listTo recover:

a Ensure that the operating system recognizes the device:

Solaris devfsadmNote: Prior to Solaris 7. you call usedrvconf ig and disks.

liP-LX ioscan -c diskinsf -e

Linux partprobe /dev/sdb

b Verify that the operating system recognizes the device:

Solaris prtvtoc /dev/rdsk/clt2dOs2

IIP-UX ioscan -fnC disk(Verify that the disk is ill CLAIMED statc.j

Linux fdisk -1 /dev/sdb

c Force the VxV!\l configuration daemon to reread all of the drives inthe system:

Lab 1 Solutions: Maintaining Data Consistency

Copyright E 2006 Svmantec Corporatmn All flyht<; reservf!rl

8-7

vxdctl enable

d Reattach the device to the disk media record:

vxreattach

e Change the state of pie x test- 01 to STALE:

vxmend -g testdg fix stale test-Ol

Change the state of plex test - 01 to CLEAN:vxmend -g testdg fix clean test-Ol

9 Recover and start the volume:vxrecover -s

4 Alter you recover the volume, type e in the lab script window. The scriptverifies whether your solution is correct.

Resolving Plex Problems: Permanent Failure

In this lab exercise, a permanent disk failure is simulated. By using the vxmendcommand, you must select the plcx that has the correct data and recover thevolume by using the clean plcx. Ilyou select the wrong plcx as the clean plcx, thenyou have corrupted the data. The lab script run_states sets up the test volumeconfiguration, simulates a disk failure. and validates your solution for recoveringthe volume. Ask your instructor for the location ofthe run_states script.

Before You Begin: Check to ensure that the environment variable DG is set to thenumc of the testdg disk group:

echo $DG

I f it is not set, set it before you continue:


From the directory that contains thc lab scripts, run thc script run_states,and select option 2. "Power failed drive (permanent failure}":

./run_states1) Lab 1 - Turned off drive (temporary failure)2) Lab 2 - Power failed drive (permanent failure)3) Lab 3 - Unknown failure4) Optional Lab 4 - Turned off drive with layeredvolume


Copyrlyhl 't 2006 Svrnantec Corporahou All flghl" ft::lSHl\ted

5) Optional Lab 5 - Power failed drive with layeredvolumex) ExitYour Choice? 2


'\Iote: If you receive an error message about the / image tile system becomingfull during volume setup, ignore the error message. This error will not haveany impact on further lab steps or lab results.

2 Read the instructions in the lab script window. The script simulates a diskpower-offby saving and overwriting the private region on the drive that is usedby the volume. lO is started so that VxVM detects the failure, and VxVMdetaches the disk.

3 In a second terminal window, replace the permanently failed drive with either anew disk at the same SCSI location or by another disk at another SCSIlocation. Note that the new disk does not have any data on it. The other plcx ofthe volume became STALE ten minutes before the drive failed. I lowever, itstill has your data, but data from the last ten minutes is missing.

Assume that the failed disk is testdg02 (cl t2dO for a Solaris or UP-UXsystem or sdb for a Limn system) with plex test-Ol, and the new diskused to replace it is clt3dO for a Solaris or HP-UX system or sdd for aLinux system, which is originally uninitialized (actual device names willvary by system). Because the newly replaced disk has no data on it, youcan only use the stale plex test- 02to recover the volume.

Note: When performing recovery procedures, run vxprint and vxdisklist often to see what is changing after issuing recovery commands:

vxprint -g testdg -htrvxdisk -0 alldgs list

To recover from the permanent disk failure:

a Invoke vxdiskadm:vxdiskadm

b From the vxdiskadm main menu, select the option, "Replace a failedor removed disk." When prompted, select cl t3dOfor a Solaris or UP-UX system or sdd for a Linux system to initialize and replacetestdg02.

'iote: If you receive an error while using vxdiskadm about avxprint operation requiring a disk group, ignore the error.

e Change the state of plex test - 02 to CLEAN:

vxmend -g testdg fix clean test-02d Recover and start the volume:

Lab 1 Solutions: Maintaining Data Consistency 8-9Copynqnt :{. 2U06 Syrnantec Corporation 1\.11rights reserved

vxrecover -s

4 After you recover the volume. type e in the lab script window. The scriptverifies whether your solution is correct.

5 When you have completed this exercise. ifthe disk device that was originallyused during disk failure simulation is in online invalid state, rcinitializcthe disk to prepare for later labs.For example:vxdisksetup -i device_tag

Resolving Plex Problems: Unknown Failure

III this lab exercise, an unknown failure is simulated. By using the vxmendcommand, you must select the plcx that has the correct data and recover thevolume by using the clean plcx. I I' you select the wrong plcx as the:clean plcx. thenyou have:corrupted the:data. The lab script run_states sets up the test volumeconliguration and validates your solution for recovering the volume. Ask yourinstructor lor the location 01 the run states scnpt


echo $DG

llit is not set. set it before you continue:


From the directory that contains the lab scripts, run the script run_states,and select option 3, "Unknown failure":. /run_states1) Lab 1 - Turned off drive (temporary failure)2) Lab 2 - Power failed drive (permanent failure)3) Lab 3 - Unknown failure4) Optional Lab 4 - Turned off drive with layeredvolume5) Optional Lab 5 - Power failed drive with layeredvolumex) ExitYour Choice? 3

This script sets up a mirrored volume named test that has three plcxes.


Copyrr!olhl ,,~,2006 Svruantec Corporal 1011 All flgnts fFlSFlrved

:\ote: If you receive an error message about the / image file system becomingfull during volume setup. ignore the error message. This error will not haveany impact on further lab steps or lab results.

2 Read the instructions in the lab script window, The script simulates anunknown failure that causes all plcxcs to be set to the STALE stare. Yuu are notprovided with infonnntion about the cause of the problem with the plexes.

3 In a second terminal window. check each plcx individually to determine if ithas the correct data. To test if the plcx has correct data. start the volume usingthat plcx, and then. in the lab script window. press Return. The script outputdisplays a message stating whether or not the plex has the correct data.Continue this process for each plcx, until you determine which plex has thecorrect data.

Because all three plexes of the volume tes t are STALE, and you do notknow which plex cuntains the good data, you must offline all but one plexand check to determine if that plex has the guod data.

If it is the correct plex, you can recover the volume.

If it is not the correct plex, repeat the ofllining of all but one plex tocheck the other plexes.

a Start by checking the data on test-Ol:

vxmend -g testdg off test-02vxmend -g testdg off test-03vxmend -g testdg fix clean test-Olvxvol -g testdg start test

b Press Return on the output of the script. The script tests the data. Ifthe pie x does not have the good data, continue by checking the data ontest-02:vxvol -g testdg stop testvxmend -g testdg -0 force off test-Olvxmend -g testdg on test-02vxmend -g testdg fix clean test-02vxvol -g testdg start test

c Press Return on the output of the script. The script tests the data. Ifthis plex has the good data, you do nut need to search any further.

4 After you determine which plcx has the correct data, recover the volume.

To recover the volume:vxmend -g testdg on test-Olvxmend -g testdg on test-03


Cr>pynghl '~/200{j Symantec Corporation All fights reserved

8-11

vxrecover

5 Alter you recover the volume, type e in the lab script window. The scriptveri lies whether your solution is correct.


Cupynylll ~. 2006 Svruamec Corpo.anon All fights reserved

Optional Lab ExercisesThe next set of lab exercises is optional and may be performed if you have time.These exercises provide additional recovery scenarios for resolving plex problemswith layered volumes. /\ final activity explores logging behavior following asystem crash.

Optional Lab: Resolving Plex Problems: Temporary Failure with aLayered Volume

In this lab exercise, a temporary disk failure is simulated. By using the vxmendcommand, you must select the plex that has the correct data and recover thevolume by using the clean plcx. If you select the wrong plcx as the clean plcx. thenyou have corrupted the data. The lab script run_states sets up the test volumeconfiguration, simulates a disk failure. and validates your solution for recoveringthe volume. Ask your instructor for the location of the run_states script.

Before You Begin: Check to ensure that the environment variable DG is set to thename of the testdg disk group:echo $DG

I fit is not set, set it before you continue:DG="testdg"export DG

From the directory that contains the lab scripts. run the script run_states.and select option 4, "Turned off drive with layered volume":./run_states1) Lab 1 - Turned off drive (temporary failure)2) Lab 2 - Power failed drive (permanent failure)3) Lab 3 - Unknown failure4) Optional Lab 4 - Turned off drive with layeredvolume5) Optional Lab 5 - Power failed drive with layeredvolumex) ExitYour Choice? 4

This script sets up a concat-mirror volume named test.

Note: If you receive an error messageabout the / image tile system becomingfull during volume setup. ignore the error message. This error will not haveany impact on further lab steps or lab results.

2 Read the instructions in the lab script window. The script simulates a diskpower-off by saving and overwriting the private region on the drive that is usedby the volume, and l/O is stalled so that V~VM detects the failure. Then. whcn


Copynght .? 2006 Syrnanter coroo-auoo All notus reserved

B-13

you arc ready to power the disk back on. the script restores the private regionas it was before the failure.


Assume that the drive that was turned off and then back on was cl t2dOfor a Solaris or HP-UX systemor sdb for a Linux systemwith the plextest-POl (actual device name will vary by system).The plex test-P02was STALE prior to the failure of the disk with the plex test -POL Whenthe disk is powered back on and reattached, the plcx test-POl continuesto contain the most up-to-date data.

Note: When performing recovery procedures, run vxprint and vxdisklist often to seewhat is changing after issuing recovery commands:vxprint -g testdg -htrvxdisk -0 alldgs list

To recover:a Ensure that the operating system recognizesthe device:

Solaris devfsadm1\011': Prior to Solaris 7. you can use drvconf ig and di sks.

HP-UX ioscan -c diskinsf -e

Linux partprobe /dev/sdb

b Verify that the operating system recognizesthe device:

Solaris prtvtoc /dev/rdsk/clt2dOs2

HP-UX ioscan -fnC disk(Writ} that the disk is in CLAIMED sturc.)

Linux fdisk -1 /dev/sdb

c Force the VxVM configuration daemon to reread all of the drives inthe system:vxdctl enable

d Reattach the device to the disk media record:vxreattach


Cupynqht '.'. 2006 svneotec Corporation All rights reserved

e Change the state of piex test-POl to STALE:

vxmend -g testdg fix stale test-POl

Change the state of plex test -POl to CLEAN:

vxmend -g testdg fix clean test-POl

9 Recover and start the volume:vxrecover -s


Optional Lab: Resolving Plex Problems: Permanent Failure with aLayered Volume

In this lab exercise,a permanentdisk failure is simulated. By using the vxmendcommand,you must selectthe plex that hasthe correct dataand recover thevolume by using the cleanplex. If you selectthewrong plcx asthe cleanplcx, thenyou havecorrupted the data.The lab script run_states setsup the testvolumeconfiguration. simulatesa disk failure. andvalidatesyour solution for recoveringthe volume. Ask your instructor for the location of the run_states script.

Before You Begin: Check to ensurethat the environmentvariable DGis set to thenameof the testdg disk group:

echo $DG

If it is not set,set it beforeyou continue:


From the directory that containsthe lab scripts. run the script run_states,and selectoption 5, "Power failed drive with layeredvolume":./run_states1) Lab 1 - Turned off drive (temporary failure)2) Lab 2 - Power failed drive (permanent failure)3) Lab 3 - Unknown failure4) Optional Lab 4 - Turned off drive with layeredvolume5) Optional Lab 5 - Power failed drive with layeredvolumex) ExitYour Choice? 5

This script setsup a concat-mirror volume namedtest.

B-15Lab 1 Solutions: Maintaining Data Consistency

Copyright .{:: 2()[)6 Symantec Corporation. All nqhts reaervec

Note: I f you receive an error message about the / image file system becomingfull during volume setup, ignore the error message. This error will not haveany impact un further lab steps or lab results.

2 Read the instructions in the lab script window. The script simulates a diskpowcr-ottby saving and overwriting tile private region on the drive that is usedby the volume, I/O is started so that VxVM detects the failure, and VxVMdetaches the disk.

3 In a second terminal window, replace the pcrmancmly failed drive with either anew disk at the same SCSI location or by another disk at another SCSIlocation. Note that the new disk does not have any data on it. The other plcx ofthe volume became STALE ten minutes before tile drive failed. However, thisplcx still has your data, but data 1i"L1I11 the last tell minutes is missing.

Assume that the failed disk is tes tdgO2 (c1t2dO for a Solaris or HP-LJXsystem or sdb for a Limn system) with pie x tes t - PO1, and the new diskthat you use to replace it with is c1t3dO for a Solaris or HP-LJXsystemor sdd for a Linux system, which is originally uninitialized (actual devicenames will vary by system), Because the newly replaced disk has no dataon it, you can only use the stale plex test-P02 to recover the volume.

Note: When performing recovery procedures, run vxprint and vxdisklist often to see what is changing after issuing recovery commands:vxprint -g testdg -htrvxdisk -0 alldgs list

To recover from the permanent disk failure:

a Invoke vxdiskadm:

vxdiskadm

b From the vxdiskadm main menu, select the option, "Replacc a failedor removed disk," When prompted, select c1 t3dO for a Solaris or HP-LJXsystem or sdd for a Linux system to initialize and replacetestdg02.

Note: If you receive an error while using vxdiskadm about avxprint uperatiun requiring a disk group, ignore thc error.

c Change the state of plex test-P02 to CLEAN:

vxmend -g testdg fix clean test-P02

d Recover and start thc volume:

vxrecover -s


Copynqnt 2006 Svmantec Corporanon All flg~lls reserved


5 When you have completed this exercise, destroy testdg.

vxdg destroy testdg


Copvncht e 1006 Syrnantec Corpo-auoo All nghts reserved

8-17

Optional Lab: Exploring Logging Behavior During a System Crash

"Iole: This section requires console accessto the lab system. I I' you arc working ina Virtual Academy lab environment, skip this section.

List the imported disk groups on your system and destroy the testdg diskgroup ifit still exists.vxdg listIf necessary:vxdg destroy testdg

2 Ifyou do not already have a disk group called namedg, create it using one ofthe already initialized disks.If necessary:vxdg init namedg namedgOl=device_tagl

3 Ensure that the namedg disk group has at least three disks in it. I f necessary.add disks to the namedg disk group.vxdisk -0 alldgs listIf necessary:vxdg -g namedg adddisk namedg02=device_tag2 \

namedg03=device_tag3

4 Create two mirrored, concatenated volumes, 500 1\1113in size, called vol logand volnolog in thc namedg disk group.vxassist -g namedg make vollog 500m layout=mirrorvxassist -g namedg make volnolog 500m layout=mirror

5 Add a log to the volume vol log.

vxassist -g namedg addlog vol log

6 Create a file system on both volumes.

Solaris, mkfs -F vxfs /dev/vx/rdsk/namedg/volnologIIP-UX mkfs -F vxfs /dev/vx/rdsk/namedg/vollog

Llnux Use - t instead of - F.

7 Create mount points for the volumes. /vollog and /volnolog.

mkdir /vollogmkdir /volnolog


Copynyrll'~ 2006 Svmantec Corpceanoo 1\11nqhts reserved

8 Copy /etc/vfstab (on Solaris) or /etc/fstab (on Linux and IIP-UXl toa file called origvfstab or origfstab.

Solaris ep /ete/vfstab /origvfstab

IIP-UX, ep /ete/fstab lorigfstabLinux

9 Edit /etc/vfstab or /etc/fstab so that vollog and volnolog aremountedautomatically on reboot.(In the tile, eachentry should be separatedby a tab.)"Ole: On the Solaris platform. ensurethat you set the mount at bootoption to yes for both tile systems.

10 Typcmountall (on Solaris and IIP-UXl or mount -a (on Linux) to mountthe vol log andvolnolog volumes.mountall

11 In root. start an I/O processon eachvolume. For example:find lusr -print epio -pmud Ivollog &find lusr -print I epio -pmud Ivolnolog &

12 Simulatea systemcrashon your systemby stopping it unexpectedlyasshownin the following.

Solaris PressStop-A. At theOK prompt.typeboot.OK? boot

II P-l:X PressCTRL-B.

Log into theGSP.GSR> rs(Entery toconfirm.)

Linux Use halt -n. thenpoweroffand poweronthesystem.halt -n

13 After the systemis running again.check the stateof the volumes to ensurethatneither of the volumes is in the sync/needsync mode.'iote: If you are not using file systemlogging for boot disk lile systems,youmay needto carry out file systemchecksfor boot disk file systems011 theconsolebefore the systembecomesoperationalagain.vxprint -g namedg -thf vollog volnolog

14 Run the vxstat commandasshown in the following. This utility displaysstatistical information about volumes andother VxVM objects. For moreinformation on this command.s,e the vxstat (1m) manualpage.

Lab 1 Solutions: Maintaining Data Consistency 8-19Copynght i 2006 Syrnantec Corporation 1\11nqtus reserved

vxstat -g namedg -fab vollog volnologThe output shows how many I/Os it tuuk to rcsynchronizc the mirrors.Cumpare the number of I/Os for each volume. What do you notice?You should notice that fewer 1/0 operations were required toresynchronize vol log. The log keeps track of data that needs to beresynchronized.

15 Unmount both tile systems and remove the volumes vol log and volnolog.umount /vollogumount /volnologvxassist -g namedg remove volume vol logvxassist -g namedg remove volume volnolog

16 Restore your original vfstab or fstab file.

Solaris cp /origvfstab /etc/vfstab

HP-UX, cp /origfstab /etc/fstabLinux

17 Destroy the namedgdisk group.vxdg destroy namedg


Copym.jhl;;:; 2006 Svmantec Corporation All "yhts reserves

syrnantec.

Lab 2



Lab 2 Solutions: Managing Devices Within the VxVM ArchitectureIn this lab, you explore the VxVM tools used to manage the device discovery layer(DOL) and dynamic mulripathing (OMP). The objective of this exercise is to makeyou familiar with the commands used to administer multipathed disks.

In the VERITAS classroom (not Virtual Academy). you also explore dynamicmultipathing through the use of two P0l1S on the liDS disk array. In the classroomconfiguration. each LUN maps to two ports on the liDS. so that a system detects aLUN twice through a single IIBA. Your instructor will change the classroomconfiguration at a certain point in the lab to enable access to the lIDS ports.effectively switching from one path to two paths to each LUN.


Prerequisite Setup

To perform this lab. you need a lab system with Storage Foundation pre-installed.configured and licensed. In addition to this. you also need a minimum of threeexternal disks to be used during the labs.

Note: Part 2 of this lab can only be performed in the standard VERITASclassrooms that include an II OS disk array.

Before you begin this lab. destroy any data disk groups that are left from previouslabs:

vxdg destroy diskgroup

Copyngtlt if 2006 Symarnec Corporation All nqtns reserved

8-21Lab 2 Solutions: Managing Devices Within the VxVM Architecture

Classroom lab Values

In preparation for this lab, you will need the following information about your labenvironment. For your reference. you may record the information here, or referback to the first lab in the SF Fundamentals section where you initiallydocumented this information.

Object Sample Value Your \'alueroot password veritas

_._--Host name trainl

I\I~' Data Disks: Solaris: clt#dO -clt#d5HP-LX: c4tOdO -c4tOd5AIX: hdi sk21-hdisk26Linux: sda - sdf

Location of Lab Scripts: /student/labs/sf/sf50

l.ocation of the £p /student/labs/sf/program: sf50/bin

8-22 VERITAS Storage Foundation 5.0 for UNIX- Maintenance

Copy"qht © 2006 Svntantec Con.oranon All fights reserved

Introduction to DMP Labs

To explore the behavior of DMP in the classroom, this lab is organized into twosections:

Part 1: In this activity, you practice using DOL and DMP administrativecommands while only one path is visible to each LUN.Part 2: In this activity, the instructor changes the classroom configuration sothat each L UN maps to both ports on the II DS, and each system detects twopaths to a LUN. Explore additional exercises to experience when two paths areIn use.Note: Part 2 can only be performed in a standard Symantec classroom (not in aVirtual Academy or Mobile Academy lab environment).


Instructor: If you did not initialize the classroom zoning configuration prior to thestart of class on day one, perform the following steps to initialize classroom zoningconfigurations. This must be completed prior to performing this lab.

Use course_setup script: Select Classroom.(Setup scripts arc all included in Classroom SAN configuration Version 2).Select Function To Perform:


2 - Select Zoning and Hostgroup Configuration by Course Name

3 - Select/Check Hostgroup Configuration

2 Select option 3 - Select/Check Ilostgroup Configuration.Select HostGroup Configuration to be Configured:1 - Standard Mode: or 4 node sharing, No DMP

2 DMP Mode: 2 node sharing, switchable between 1 path and 2path access3 - Check active HDS Hostgroup Configuration

3 Select option 2 - DMP Mode. Wait and do not respond to prompts.

4 Exit to first level menu.

5 Select option I - Select Zoning by Zone Name.Select Zoning Configuration Required:1 - Mode 1: 6 sets of 2 Systems sharing 12 LUNs, no Tape Libraryavailable (HDS DMP Mode 6 x 2 Systems - Single Path to 12LUNs)

6

2 - Mode 2: 3 sets of 4 Systems sharing 24available (HDS DMP Mode - 6 x 2 Systems

Select option I - Mode I (single path to 12 LUNs).

LUNs, no Tape LibraryDual Paths to 12 LUNs)


S Exit out of the course_setup script.

9 Reboot each system using reboot - - - r.

Lab 2 Solutions: Managing Devices Within the VxVM Architecture 8-23COPYrlght:[., 2006 Symantec Coccor ano«. All fights reserved

Part 1: Exploring DMP (Single Path Visible)

Administering the Device Discovery Layer

Display the J80Ds currently supported on your system by using V.xVM'sdevice discovery layer utility, vxddladm. Use manual pages to identity theoption you need to use with the vxddladm command.man vxddladmvxddladm listjbod

2 List all currently supported disk arrays.

Nete: If your lab environment is using Hitachi 9500 array, note that this arrayis included in the libvxhdsalua library that is already included in VxVM5.0 by default.

vxddladm listsupport

3 List all the enclosures connected to your system using the vxdmpadm1i stenclosure all command. Docs Volume Manager recognize the diskan'ay you arc using in your lab environment' What is the name of theenclosure'

vxdmpadm listenclosure allVolume ,\1anager recognizes the disk array if it is among the supporteddisk arrays you listed in step 2. If you arc working in a standard Symantecclassroom with an Hitachi 9500 array, you should see HDS9500-ALUAOdisplayed as the enclosure name of the disk array connected to yoursystem.

4 Set your system to use enclosure-based naming.vxdiskadm

Select the option, "Change the disk-naming scheme" and complete theprompts to select enclosure-based naming.

5 Display the disks attached to your system and note the changes.vxdisk -0 alldgs listFor example, if your classroom is configured with an Hitachi array, youwill see the Hitachi tags in the output. The disks will be namedenc]osUl"e_name_#, for example HDS9500 -ALUAO_0.

6 Rename the enclosure to yourname using the vxdmpadm setat trcommand. To find the exact command syntax, check the manual pages for thevxdmpadm command.

Note: The original name of the enclosure is displayed by the vxdmpadmlistenclosure all command that you used in step 3.vxdmpadm setattr enclosure orig_name name=yourname


Copynqhtc 2006 Symantec Corporanoo 1\11nqbts reserved

7 Launch VEA. connect to your local system. and notice any differences in howdisks are represented.

yea &


List all controllers on your system using the vxdmpadm I istct I raIlcommand. l Iow many controllers are listed for the disk array your system isconnected to?

vxdmpadm listctlr allIf you are in a standard Symantec classroom, you should observe only onecontroller listed for the enclosure you renamed to yourname.

2 Display all paths connected to the controller listed for the disk array on yoursystem using the vxdmpadm getsubpaths ctlr=controllercommand. Compare the NAME and the DMPNODENAME columns in the output.

vxdmpadm getsubpaths ctlr=controllerThe NAME column lists all of the disk devices that the operating systemsees whereas the DMPNODENAME column provides the corresponding DM!'node name used for that disk device. If you have not switched to enclosurebased naming, these names will be the same. Note that the DMP nodenames are the ones displayed by VEA or by the vxdisk -0 alldgslist command.

3 In the displayed list of paths . use the OMP node name of one of the paths todisplay information about paths that lead to the particular LUN. I low manypaths can you see'!

vxdmpadm getsubpaths dmpnodename=dmpnodenameIf you are in a standard Symantec classroom, at this stage in the lab youare using a single path to the disk array. Therefore, you should observeonly one path listed for each DMP node name.

In the next three sections you will investigate preventing rnultipathing to a specificdevice. changing OMP JiO policies, and displaying DMP statistics. If you areworking in an environment where the SAN zoning can be changed to provide dualpaths to the disk devices. for example in a standard Symantcc classroom. skipthese sections and start with Part 2 Exploring DMP (Dual Paths Visible). The samesections will be repeated when dual paths to disk devices arc available.

Note: Dual paths to disk devices are not available in Virtual Academy or MobileAcademy lab environments.

Lab 2 Solutions: Managing Devices Within the VxVM Architecture 8-25Coovoqnt s. 2006 Svrnamec Corporation All nqbts fBsPfved


Note: Perform this section only if you cannot change your environment to use dualpath, to disks. Otherwise, skip to Part 2 Exploring DMP (Dual Paths Visible).

1 List the paths I()!' each DM P node name displayed in the enclosure basednaming scheme to identify two of the disks that were assigned to you.Nute: Alternatively, you can use the output of the vxdmpadmgetsubpaths ctlr=controliercolllmand to find the pathcorresponding to each dmp node name. On the Solaris platform, the vxdisk-e list command also provides informauon about the native OS name thatcorresponds to each drnp node name.

Until you id~ntify two or the disks assigned to yuu:

vxdisk list name_#

2 Create a disk group named namedg that contains thc two disks you identifiedin step I.vxdisksetup -i device_tag (if necessary)vxdg init namedg namedgOl=device_tagl \

namedg02=device_tag2Note that yuu should use the enclosure based names as the device tags,

3 Display multipathing information for one of the disks in the namedg diskgroup.

vxdisk list device_tagWhen you list disk information, multipathing information is displayed atthe end of the command output. The number of paths to the disk and thestate of the paths (enabled or disabled) is displayed. If the hardware is setto single-pathing and is nut set up to support mullipathing, then thenumber of paths is I.

4 Select a device in the namedg disk group on your system, and preventmuliipathing tor that device. Note that you have to exit the vxdiskadm menucompletely before the change takes affect.Note: When you arc prompted to enter the disk name, you have to enter theactual device name, not thc DM!' node name. On the Solaris platform. you canuse the list option to identify the actual device names that correspond to theDMP node names.

Invoke the vxdiskadm mcnu.

Select the option "Prevent multipathiug/Suppress devices from\'x\'M's view."

Fullow the instructions to select a disk for which you will preventmultipathing by using the option "Prevent muUipathing of a disk by\'xVM."

8--26 VERITAS Storage Foundation 5.0 for UNIX. Maintenance

Copyngtll ';,2006 Svor.nuec Corpocancn 1\11rights reserved

Note: On some platforms, such as UP-UX, you are asked if you wantthe change to take affect after a reboot. You can implement animmediate change because the disks do not have any actual VxVMobjects to he concerned about.

Exit the vxdiskadm menu to complete the operation.

5 Verify that multipathing has been prevented for the device.

Invoke the vxdiskadm menu.

Select the option "List currently suppressed/non-multipatheddevices."

The device that you suppressed is displayed in the output of this menuoption.

6 Run the vxdisk -0 alldgs 1ist command and notice the name andlocation of the disk in the list.

vxdisk -0 alldgs listThe disk naming convention has changed back to standard for that disk.

7 Re-cnable muhipathing for this device and verify your action. Note that youhave to exit the vxdiskadm menu completely before the change takes affect

Invoke the vxdiskadm menu.

- Select the option "Allow multipathing/Unsuppress devices fromV,VM's view",Follow the instructions to select the disk for which you will re-enablemultipathing b~ using the option" Allow multipatbing of a disk byVxVI\1".

Exit the vxdiskadm menu to complete the operation.

Note: Depending on your platform, the vxdi skadm menu may prompt you toreboot your system. Reboot your system if prompted by the vxdi skadmmenu.

To verify your action, invoke the vxdiskadm menu, and select the option"List currently suppressed/non-multipathed devices". There should be nodevices listed in the output of this menu option.

8 Run the vxdi sk - 0 aIldgs 1i st command and notice the names andlocation of the disk in the list.

vxdisk -0 alldgs listThe disk is back in enclosure-based naming mode.

Lab 2 Solutions: Managing Devices Within the VxVM Architecture 8-27COPYright 'f, 2006 Svmamac (orpor.:!lIOfl All rl91115 reserved


Note: Perform this section only if you cannot change your environment to use dualpaths to disks. Otherwise, skip to Pm11 Exploring DM P (Dual Paths Visible).

1 Create a I-CiB volume named namevoll in the namedg disk group.vxassist -g namedg make namevoll Ig

2 Enable the gathering of I/O statistics lor DMP.vxdmpadm iostat start

3 Reset the DMP I/O statistics counters to zero.

vxdmpadm iostat reset

4 Next, you will use a simple performance utility, called f p, to generate l/O onthe disk used by the namedg disk group. Ask your instructor lor the locationof the program. In a different terminal window, start several invocations olthcfp program by using the following command:/ scr.lpt .1,)(.,;::!ti en! fp ple t ro.?-m

jdevjvx/rdsk!1l.ow:edg!n:unevol1 1048576 32 99999 rw &

To create enough 1;0 resistance, use the vi editor and copy about 10 oftheselines into a file called !tmp/testscript, and then run the script

Notc: Make sure that you arc using the COITectversion ofthe fp program loryou I platform, 101example, fp sun

5 In the original terminal window. display 1/0 statistics for all controllers.

vxdmpadm iostat show all

6 Display 1/0 statistics lor the DMP node that corresponds to the device used bynamevoll. Display statistics every two seconds for four times.

Note: You can use the vxprint -g namedg -htr namevollcommand to idcnti ty the dmp node n.unc of the device used by namevoll.

vxdmpadm iostat show dmpnodename=nodename interval=2 \count=4


Note: Perform this section only if you cannot change your environment to use dualpaths to disks. Otherwise, skip to Part 2 Exploring DMP (Dual Paths Visible).

1 Display the current I/O policy for thc enclosure you arc using.

vxdmpadm getattr enclosure yourname iopolicy


Copynqhl ,(:, 2006 Syrnantec Cornoranon 1\11nqtus reserved

The default 1/0 policy is round-robin for the array used in standardSymantec classrooms.

2 Change the current I/O policy for the enclosure to stop load-balancing and onlyuse multipathing for high availability.vxdmpadm setattr enclosure yourname \

iopolicy=singleactive

Solaris ps -ef I grep fp-

sun I awk '{print $2} , I \xargs kill -9

liP-LX ps -ef I grep fp_hp I awk '{print $2} , I \xargs kill -9

3 Display the new I/O policy attribute.vxdmpadm getattr enclosure yourname iopolicy


5 Destroy the namedg disk group.vxdg destroy namedg

6 Set your system back to traditional naming.vxdiskadmSelect the option, "Change the disk-naming scheme" and complete theprompts.

Lab 2 Solutions Managing Devices Within the VxVM Architecture B-29COPyfl9ht '0 2006 Symantec Corporation. All flglltS reserved

Part 2: Exploring DMP (Dual Paths Visible)

Note: The following labs are intended for a muhipath environment and do notmake sense with a single path. These activities may be performed only in theSymantec classroom environment, not in the Virtual Academy or Mobileenvironments.


Instructor: Perform the following steps to switch dual paths on. Switch to zoneconfiguruuon Z to enable a second path to the LUNs:

1 Use course_setup script: Select Classroom. Setup scripts arc all includedin Classroom SAN configuration (Version 2).Select Function To Perform:


2 - Select Zoning and Hostgroup Configuration by Course Name3 - Select/Check Hostgroup Configuration

2 Select option 1- Select Zoning by Zone Name.Select ZOIling Configuration Required:

Mode 1: 6 sets of 2 Systems sharing 12 LUNs, no Tape Libraryavailable (HDS DMP Mode - 6 x 2 Systems - Single Path to 12LUNs)2 - Mode 2: 3 sets of 4 Systems sharing 24 LUNs, no Tape Libraryavailable (HDS DMP Mode - 6 x 2 Systems - Dual Paths to 12 LUNs)

3 Sclcct Z to switch to dual paths.


5 Exit out of the coursesetup script.

6 Reboot each system using reboot - r.


List all controllers on your system using the vxdmpadmlistctlr allcommand. How many controllers arc listed for the disk array your system isconnected to'!

vxdmpadm listctlr allIf you are in a standard Symanrec classroom, ynu should still observe onlyone controller listed for the enclosure. :'oIotethat the J)'VIP capabllity isillustrated by using dual ports on the disk array but the system still uses asingle controller to connect to the SA:'oI.


Cupyngh\ <t:' 2006 Symantec Corporation All nyhts reserved

2 Display all paths connected to the controller listed for the disk array on yoursystem using the vxdmpadm getsubpaths ctlr=controllercommand. Compare the NAME and the DMPNODENAME columns in the output.vxdmpadm getsubpaths ctlr=controllerTIll' NAME column lists all of the disk devices that the operating systemsees whereas the DMPNODENAME column provides the cur responding DM I)nude name used for that disk device. After you switch to dual paths, youshould notice that the same DMP node name is listed for two devices.

3 In the displayed list of paths, use the DMP node name of one of the pathstodisplay information about paths that lead to the particular LUN. Ilow manypaths can you see')vxdmpadm getsubpaths dmpnodename=dmpnodenameIf you are in a standard Symantec classroom, at this stage in the lab youhave switched to dual paths to the disk array. Therefore. you shouldobserve two paths listed for each DMP node name.


List the paths for each dmp node name displayed in the enclosure basednaming scheme to identify two of the disks that were assigned to you.Tu identify two of the disks assigned tu you:

vxdisk list name_#

2 Create a disk group named narnedg that contains the two disks you identifiedin step I.vxdisksetup -i device_tag (if ncccssarv)vxdg init namedg namedgOl=device_tagl \

namedg02=device_tag2:\otl' that yuu shuuld use the enclosure based names as the device tags.

3 Display multiparhing information for one of the disks in the narnedg diskgroup.vxdisk list device_tagWhen you list disk information, multipathing information is displayed atthe end of the command output. The number of paths to the disk and thestate of the paths (enabled or disabled) is displayed. After switching todual paths you should observe two paths at the end of the commandoutput.

4 Select a device in the narnedg disk group on your system. and preventmultipathing for that device. Note that you have to exit the vx d i skadm me11Ucompletely before the change takes affect.

Lab 2 Solutions: Managing Devices Within the VxVM Architecture 8-31COP}flghl ~,2006 Svrnantec Corporation All fights reserved

Note: When you arc prompted to enter the disk name, you have to enter theactual device name, not the dmp node name. 011the Solaris platform, you canuse the list option to identify the actual device names that correspond to thedmp 1I0d.:names.

Invoke the vxdiskadm menu.- Select the option "Prevent muitipathing/Suppress devicesfrom

VxVM's view."Follow the instructions to selecta disk for which you will preventmuitipathing b) using the option "Prevent muitipathing of a disk byVxVM."Note: On someplatforms, such as HP-lIX, you arc asked if you wantthe change to take affect after a reboot. You can implement animmediate change becausethc disks do not have any actual VxVMobjects to be concerned about.Exit the vxdiskadm mcnu to complete the operation.

5 Verify that multipathing has been prcv cntcd for the device.Invoke the vxdiskadm menu.

- Select the option "List currently suppressed/non-multipatheddevices."The device that you suppressedis displayed in the output of this menuoption.

6 Run the vxdisk - 0 alldgs 1ist command and notice the names andlocation or the disk in the list.vxdisk -0 alldgs listThe disk nanung convention haschanged back to standard for both pathsof that disk.

7 Rc-cnablc multipathing for this device and verify your action. You need toenable multipathing for both paths olthc device. Note that you have to exit thevxdiskadm menu completely before the change takes affect.

invoke the vxdiskadm menu.- Select the option "Allow multipathing/Unsuppress devices from

VxVM's view".Follow the instructions to selectthe disk for which you will rc-enablemultipathing by using the option "Allow multipathing of a disk byVxVM".

- When prompted if you would like to enable muiripathing for anotherdevice, type y and enter the secondpath for the device.Exit the vxdiskadm menu to complete the operation.


Copyfl~hl c- 2006 Svruantec Corporauon. 1'1.11tights reservec

Note: Depending on your platform. the vxdiskadm menu may prompt you toreboot your system. Reboot your system ifprompted by the vxdiskadmmenu.

To verify your action, invoke the vxdiskadm menu, and select the option"List currently suppressed/non-multipathed devices". There should be nodevices listed in the output of this menu option.

8 Run the vxd i sk - 0 alldgs 1 i st command and notice the names andlocation of the disk in the list.

vxdisk -0 alldgs listThe disk is back in enclosure-based naming mode and only one device islisted for both paths of the disk.


Create a I-GB volume named namevoll in the namedg disk group.

vxassist -g namedg make namevoll 19

2 Enable the gathering of 1/0 statistics for DMP.

vxdmpadm iostat start

3 Reset the OM P I/O statistics counters to zero.

vxdmpadm iostat reset

4 Next, you will use a simple performance utility, called fp, to generate 110onthe disk used by the namedg disk group. Ask your instructor II)r the locationof the program. In a different terminal window, start several invocations of thefp program by using the following command:/SI..','l'ipt .._.l()ca::i;:Jn!fp j:·la iciiu \

/dev/vx/rdsk/!1 .."i'edg/I1,c;"""'voll 1048576 32 99999 rw '"

To create enough 110resistance, use the vi editor and copy about 10 of theselines into a me called /tmp/testscript, and then run the script

:\ote: Make sure that you are using the correct version of the fp program foryour platform, for example, f p_ sun.

5 In the original terminal window, display I/O statistics for all controllers.

vxdmpadm iostat show all

6 Display 110 statistics for the DM P node that corresponds to the device used bynamevoll. Display statistics every two seconds for tour times.

Lab 2 Solutions: Managing Devices Within the VxVM Architecture B-33CopYrlght,f; 2()06 Symanter- Corporsuon All flQt1ts reserved

Note: You can use the vxprint -g namedg -htr namevollcommand to identify the dmp node name of the device used by namevoll.


7 Ki II all f p processes.._-

Solaris ps -e£ I grep £p sun I awk '{print $2}' I \-

xargs kill -9

HP-UX ps -e£ I grep £p hp I awk • {print $2}' I \-xargs kill -9


Display the current I/O policy Ill!' the enclosure you are using.vxdmpadm getattr enclosure yourname iopolicyThe default 1/0 policy is round-robin for the array used in standardSymantec classroums,

2 Change the (UnTIl! I/O policy lor the enclosure to stop load-balancing ami onlyuse multipathing for high availability.vxdmpadm setattr enclosure yourname \

iopolicy=singleactive

3 Display the new I/O policy attribute.vxdmpadm getattr enclosure yourname iopolicy

4 Reset the DMP I/O statistics counters to zero,vxdmpadm iostat reset

5 Next. you will use the fp program again. to generate I/O on the disk used bythe namedg disk group. Ask your instructor for the location or the program. Ina different terminal window, start several invocations or the fp program byusing the following command:I :'::::"T.ipt_lc'c;;:·'tt cu/fp._.p.l.:"tcf..·'L!if \

!dev!vx!rdsk/n.'""edg/na",evoll 1048576 32 99999 rw &

To create enough 1/0 resistance. use the vi editor and copy about 10 or theselines into a file called /tmp/testscript. and then run the script.Note: Make sure that you arc using the correct version otthc fp program foryour platform. for example. fp _ sun.

6 In the original terminal window. display I/O statistics lor all controllers.vxdmpadm iostat show all


Copyflghl:;:' 2006 Svm.mtec Corporancn All nqhls resorve-t

7 Display 110 statistics for the DMP node that corresponds to the device used bynamevoll. Display statistics every two seconds for four times. Compare theoutput to the output you observed before changing the DMP policy tosinglcactivc.

Note: You can use the vxprint -g namedg -htr namevollcommand to identify the drnp node name of the device used by namevoll.


Solaris ps -ef I grep fp_sun I awk '{print $2}' I \xargs kill -9

" P-L'X ps -ef I grep fp hp I awk ' {print $2}' I \--xargs kill -9


9 Change the DMP 110 policy back to its default value (round-robin).

vxdmpadm setattr enclosure yourname \iopolicy=round-robin


vxdg destroy namedg


vxdiskadmSelect the option, "Change the disk-naming scheme" and complete theprompts.

Managing the DMP Restore Daemon

Check the status of the DMP restore daemon.vxdmpadm stat restoredNote the values of the daemon interval and policy.

2 Change the restore daemon interval to 400 seconds and change the policy toanalyze all paths in the system.

vxdmpadm stop restorevxdmpadm start restore interval=400 policy=check_.all

3 Verify the changes that you made.vxdmpadm stat restored

Lab 2 Solutions: Managing Devices Within the VxVM Architecture 8-35Copynght'S 2006 Sym8111ec Coeoorauo- 1\11fl!i!ltS reserved

4 Change the daemon interval and policy back to the original values.

vxdmpadm stop restorevxdmpadm start restore interval=300policy=check disabled

5 Verify the changes that you made.vxdmpadm stat restored


Copvnqht '.' ;,>00£ Symantec Corpor auo» All fights reserved

s)'1l1antee.

Lab 3



Lab 3 Solutions: Encapsulation and RootabilityIn this practice. you create a boot disk mirror. disable the boot disk. and boot upfrom the mirror. Then you boot up again from the boot disk. break the mirror. andremove the boot disk from the boot disk group. Finally, you rcencapsulate the bootdisk and re-create the mirror. These tasks are performed using a combination of theVEA interface. the vxdiskadm utility. and Cl.I commands.


Prerequisite Setup

To perform this lab. you need a lab system with Storage Foundation pre-installed.configured and licensed. In addition to this. you also need a second internal disk tobe able to mirror the system disk.

On the IIP-UX platform, you also need three external disks to carry out the labs onLVM to VxVM conversion.

Some of the lab steps may require con sole access. I f you arc working in a VirtualAcademy lab environment where you do not have console access to the lab system.you will be asked to skip these steps.

Lab 3 Solutions: Encapsulation and Rootability B-37Copvnqht S 2UOfl Svmantec Corpo-auoo All nghls reserved


In preparation fur this lab. you will need the following information about your labenvironment. For your reference, you may record the information here, or referback to the first lab in the SF Fundamentals section where you initiallydocumented this information.

Object Sample Value Your Valuerunt password veritas

Host name trainl

My Boot Ilisk: Solaris: cOtOdO

HP-LX: c It ISdO

AIX: hdiskO

Linux: hda


HP-l:X: c3tlSdO

AIX: hdiskl

Linux: hdb

I\Jy Data Disks: Solaris: c i t#dO -

clt#d5

HP-UX: c4tOdO -

c4tOd5

i\IX: hdisk21-hdisk26

Linux: sda - sdf


Curyn\jht :;-: 2006 Syrnantec Corporation All fights reserved

Solaris and Linux Only: Encapsulation and Boot Disk Mirroring

Note: The encapsulation and boot disk mirroring labs vary by platform due to theway in which the boot disk is handled by the operating system. This labsection applies to Solaris and Linux only. Labs for IIP-UX are presented inthe nex t section.

Encapsulation and Boot Disk Mirroring - Solaris and Linux

Use vxdiskadm to encapsulate the boot disk. Use systemdg as the name ofyour boot disk group and use rootdisk as the name of your boot disk.

Note: If you are accessing your lab system remotely as in a Virtual Academylab environment, you will lose your connection to your lab system "hen youreboot your system after boot disk encapsulation. Wait for the system to comeback up to reconnect. If you cannot log back in within a reasonable Ul1lOUIll oftime. contact your instructor.

Select the vxdiskadm option, "Encapsulate one or more disks," andfollow the steps to encapsulate your system disk. Select the system disk asthe disk to encapsulate. Add the system disk to a disk group namedsys temdg. Specify the name of the disk as rootdisk. Shutdown andreboot after exiting vxdiskadm.

2 After the reboot. use vxdiskadm to add a disk that will be used for the mirrorof root disk. If your system has two internal disks, use the second internaldisk on your system for the mirror. (This is required due to the nature of theclassroom configuration.) When setting up the disk. ensure that the disk layoutis s I iced. Use a I tboot as the name of your disk.

Select the vxdiskadm option, "Add or initialize one or more disks," andfollow the steps to add a disk to the systemdg disk group. Select thesecond internal disk as the device to add. Add the disk to the systemdgdisk group. Specify a sliced format when prompted. Specify the nameof the disk as al tboot.

3 Next. use vxdiskadm to mirror your system disk, rootdisk, to the diskthat you added. a I tboot.

Select the vxdiskadm option, "Mirror volumes on a disk," and follow thesteps to mirror the volumes. Specify the disk containing the volumes to bemirrored as rootdisk. Specify the destination disk as al tboot.

Open a separate window and monitor the mirroring progress using thevxtask moni tor command for each of the volumes being mirrored onthe boot disk. Use Ctrl+c to exit the command.vxtask monitor

Lab 3 Solutions: Encapsulation and Rootability 8-39Copvnqht f" 2006 Syrnanter Coree-anon. 1\11fights reserveo

This command shows the percentage complete of the volume beingmirrored.

4 After the mirroring operation is complete, verify that you now have two disksin systemdg: rootdisk and al tboot, and that all volumes are mirrored.Also, check to determine if rootvol is enabled and active.

Hint: Use vxprint and examine the STATE fields.

vxprint -g systemdg -htrThe rootvol should be in the ENABLED and ACTIVE state, and youshould also see two plexes for each of the volumes in sys temdg.

Solaris

5 Place the names of your alternate boot disks in persistent storage.

a.Check the values in eepromand verify the names of youralternate boot disks in persistent storage. Ensure the use-nvr amrc>variable is set to true. use the eepromcommand tosee the current settings and to set the new values. if needed.

h.Write down the values of the vx-rootdisk and vx-altbootvariables.

eeprom igrep vx-The vx- rootdi sk value is the disk alias for the original bootdisk and the vx -a1tboot value is the alias for the mirror of theboot disk.

c.use eepromto see if the use-nvramrc? value is set to true.eeprom igrep nvramrc

d. If the value is set to true. go to the next step where you test thatthe mirror of the system disk is boorable. If the value is set tofalse. perform the following additional eepromcommands:

From the command line, set the ecprom variable to enable VxVMto create a device alias in the openboor program.

eeprom use-nvramrc?=trueVerify that the new values are in place by typing ceprom again.

eeprnm

l.lnux :'iolc: You need console access to be able to perform this step on theLinux platform. If you arc working in a Virtual Academy labenvironment. skip this step.

To set the 13105 on the PC systems. you must enter system setupupon boot uud add the mirror disk into the boot sequence.

Press i after the boot loader window shows.

8-40Copyflq!1I -, 2006 SY!l1i1J\ler; Curp(>f<l\lO!1 All rights rese-veo


Note: The following steps (steps 6-11) in this lab section require console access. Ifyou are working ill a Virtual Academy lab environment with no consoleaccess, skip to the last step (step 12) of this section.

6 Test that the mirror of the system disk is bootable.

Solaris

Linux

a, Sync the disks then bring the system down to the OK prompt.

sync; syncinit 0

h. Print the environment settings at the OK prompt.OK> printenv

c. Use the boot disk alias vx-al tboot to boot up trom ihealternateboot disk.

OK> boot vx-altbootd. After the system is booted back up from the alternate boot disk.

verify which boot disk is used.eeprom Igrep devaliasNote the value or the alternate hoot disk variable.

e. Run the prtconf command to view which disk the system iscurrently booted from.prtconf -vp I grep bootpathCompare the values to validate you are bootee! oIT the mirror.

f. After you have veri lied that the mirror of the boot disk is bootahlc,rebootthc systcm tu be booted off the original boot disk.sync; syncinit 6

g. After the system comes back up. verify that the original boot diskis being used.eeprom Igrep rootdisk

h. :-.iote the value ofthe disk,

prtconf -vp Igrep bootpath

i. Compare the two values of the disk and confirm you are booted 01'1'the original disk.

In our training classrooms, the Dell Opiiplcx GX270 rcs have a810S which supports tuilmg oyer to and booting from an alternatemirror disk. in the event of boot disk failure. So now. when thesystem boots. it should automatically recognize the secondary harddrive (altboot) and boot from it.

Lab 3 Solutions: Encapsulation and Rootability

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7 Now that you arc running off the original boot disk. tail the disk. The systemwill continue to run because you have a mirror ofthe disk.

a Fail the system disk.

Todisable the bout disk and make root vol- 01 disabled and offline. usethe vxmend command. This command is used to make changes toconfiguration database records. Here, you are using the command to placetile plcx in an uilline state. For more information about this command, seethe vxmend (1m) manual page.

vxmend -g systemdg off rootvol-Ol

b Verify that rootvol- 01 is nowdisabled and offline.

vxprint -htr

c To change the plcx to a STALE Slate. run the vxmend on command onroot vol- 01. Verify that root vol- 01 is nowin the DISABLED andSTALE state.

vxmend -g systemdg on rootvol-Olvxprint -htr

8 Now that you have simulated the failure of tile uriginal boot disk, reboot thesystem and bout up on the mirror.

a Reboot the system using ini t 6.

init 6

b The system stops during the reboot at the OK prompt and indicates lor youto use vx- al tboot. Boot from the alternate boot disk

OK> boot vx-altboot

9 After the system comes back up, check the status ofthe root volume. What isthe state or the volume')

vxprint -htrThe volume with the plexes being synchronized is in the SYNC state.The other plexes are in Ihe NEEDSYNC state.

Use the vxtask 1i st commandto see the progress ofthe rcsynchronizationor the root volume.

(use the following commands a few times to see the progress)

vxtask listvxprint -htr

10 Alter the synchronization is complete, verify the status of root vol. Verifythat rootvo1- 01 is now in the ENABLED and ACTIVE state.

Note: You may need to wait a few minutes for the state to change from STALEto ACTIVE.

B-42 VERITAS Storage Foundation 5.0 for UNIX. Maintenance

Copyright '!-' {006 SymimlflC Corporanon All fights reservec

vxprint -thfYou have successfully booted up from the mirror, and the volumes have beenresynchronizcd,

11 Your system is currently booted lip from the hoot disk mirror. To hoot up fromthe original boot disk. reboot again using init 6.

init 6You have now booted up from the original boot disk.

Note: If you arc working in a Virtual Academy lab environment with no consoleaccess. you can continue with step 12.

12 Remove the mirror of the boot disk. Using VEA, remove all but one plex ofroot vol, swapvol, usr, var, opt. and home(that is, remove the newerplex from each volume in systemdg).

For each volume in systemdg, remove all of the newly created mirrors.More speclflcally, for each volume, two plexes are displayed, and youshould remove the newer (-02) piexesfrom each volume. To remove amirror, highlight a volume and select Actions->Mirror->Remove.

In preparation for the next lab. leave the boot disk encapsulated. but not mirrored.

Optional Lab: Unencapsulating - Solaris and Linux

If you want to test the vxunroot process for uncncapsularing the boot disk. youcan do the following steps. However, you need the boot disk encapsulated for thenext lab. So after performing this optional exercise, you will need to encapsulate.but not mirror, your boot disk.

Run the command to convert the root volumes back to disk partitions.vxunroot

2 Shut down and restart the system when prompted.Nute: If you arc accessing your lab system remotely as in a Virtual Academylab environment. you will lose your connection to your lab system when youreboot your system. Wait lor the system to come back up to reconnect. If youcannot log back in within a reasonable amount of time. contact your instructor.

3 Verify that the mount points are now slices rather than volumes.df -k

4 In preparation fur the next lab. leave the boot disk encapsulated, but notmirrored.

Lab 3 Solutions: Encapsulation and Rootability 8-43

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HP-UX Only: Putting the Boot Disk Under VxVM Control and Boot DiskMirroring

Notc: The encapsulation and boot disk mirroring labs \'ary by platform due to theway in which the boot disk is handled by the operating system. Thefollowing lab sections apply to H P-U X only. Labs for Solaris and Linux arepresented in the previous sections.

Putting the Boot Disk Under VxVM Control and Boot Disk Mirroring -HP-UX

:'IIotc: This lab section requires console access. lfyou arc working in a VirtualAcademy lab environment with no console access. skip this lab section andgo to the LVM to VxVM Conversion lab section.

Take the system into single user mode (init level I).

init 1

2 Check the status or the second internal disk using the vxdisk listcommand. I I' the disk is displayed as an LVM disk. ensure that it is not used byany active LVM volume groups and take it out or LVM control using thepvremove command.

Note: ltthc pvremove command fails due to an exported volume groupinformation lclt on the disk, re-create an LVM header using the force option(pvcreate -f /dev/rdsk/device_name) before using thepvremove command to remove it.

vxdisk listIf necessary:vgdisplay -v /dev/vgOOpvcreate -£ /dev/rdsk/c3tlSdOpvremove /dev/rdsk/c3tlSdOwhere c3tlSdO is the device name of thc second internal disk.

vxdctl enablevxdisk list

3 Check the values ofthe primary and alternate boot devices using the setbootcommand.

setboot

4 Create a bootablc VxVM system disk on the second internal disk using thevxcp 1vmroot command and make this disk the pnrnary boot disk Usesystemdg as the disk group to put the boot disk in.


C()pyn\lhtr.~2006 Symantec Corpcranon All ('gillS re serveu

vxcp_lvmroot -g systemdg -v -b c3tlSdOwhere c3tlSdO is the second internal disk.

5 When the vxcp_1 vmroot command completes. check the output of thesetboot command and verify that the primary path is the VxVM disk.

setboot

6 Reboot the system. After it boots up. verify that it is booted on VxVM volumesby checking the output of the bdf command.

shutdown -ry nowbdf

7 Destroy the internal disk that was used as the LVM system disk.

vxdestroy_lvmroot -v cltlSdOwhere cltlSdO is the first internal disk (the original LVM boot disk).Confirm when prompted.

8 Mirror the system disk to the other internal disk that used to be the LVM disk.

Note: This operation can take some time depending on the sizes of thevolumes on your system disk.vxrootmir -v -b clt15dO

9 Verify the primary and alternate boot paths and check the volume layouts ofthe volumes in the bootdg.setbootvxprint -g bootdg -htr

10 Reboot your system using shutdown - ry nowand interrupt the automaticboot process.

shutdown -ry nowPressany key to interrupt the boot processwhen the following messagesappear:Processor is booting from first available device.To discontinue, press any key within 10 seconds.You should see"Boot terminated." messagefollowed by the Mainmenu.


Main Menu: Enter command or menu> bo altInteract with IPL (Y, N, or Cancel)? n

12 When the system is lip. disable the root volume plex that is on the primary bootdevice using the vxmend of f command followed by vxmend on.vxmend -g bootdg off rootvol-Ol

Lab 3 Solutions: Encapsulation and Rootability B-45Copvnqm g 2006 Svmanrsr. Corporation All flQlltS eeservec

vxprint -g bootdg -htr rootvol (rootvol-01 should be inDISABLED/OFFLINEstale)vxmend -g bootdg on rootvol-Olvxprint -g bootdg -htr rootvol (rootvol-Ol should be inDISABLED/STALEstate)

13 Reboot your system using shu tdown - ry now and follow the boot-upmessages. What did you observe?

shutdown -ry nowMessages are displayed indicating thaI the rootvol volume does nothave a valid plex on the primary boot disk and that you should userootdisk02 to boot the system up. The bool process is then aborted andt he system is halted.

14 Reset the system using Service Processor login as follows:

CTRL-BService Processor login: <CR>(if necessarv)Service Processor password: <CR>(if necessary)

GSP>rs

Type Y to confirm your intention to restart the system:(Y/[N]l y

GSP>

15 lntcrrupt thc automatic boot process and boot the system using the alternateboot device.

Press any key to interrupt the boot process when the following messagesappear:Processor is booting from first available device.To discontinue, press any key within 10 seconds.You should see "Boot terminated." message followed by the Main menu.Main Menu: Enter commandor menu> bo altInteract with IPL (Y, N, or Cancel)? n

16 When the system is up and running display the state of the root volume andplcxcs. Check if there arc any synchronization tasks being carried by volumemanager using the vxtask 1 ist command. Wait for the synchronization tocomplete.vxprint -g bootdg -htr (the rootvol-Ol plex will be inENABLED/STALEstate until the synchronization is complete. The statewill change to ENABLED/ACTIVEafter the synchronization completes.)


Copvnqht !:. 2006 Syorantec Corpor aucn All nqhts reserved

vxtask list (you should observe the atomic copy synchronizationoperation initiated bv vxrecover command and the percentage that iscompleted)

17 When the state ofthe first rootvol plcx changes back to ACTIVE, remove thesecond mirrors on the alternate disk from each volume. Take the alternate diskout of the disk group and un initialize it.

Note: The volumes you have on your system disk in your lab envirnnmentcan be different from the volumes shown in the following sulutlun.vxprint -g bootdg -htrvxplex -g bootdg -0 rm dis rootvol-02vxplex -g bootdg -0 rm disk standvol-02vxplex -g bootdg -0 rm disk varvol-02vxplex -g bootdg -0 rm disk usrvol-02vxplex -g bootdg -0 rm disk tmpvol-02vxplex -g bootdg -0 rm disk optvol-02vxplex -g bootdg -0 rm disk swapvol-02vxplex -g bootdg -0 rm disk homevol-02vxprint -g bootdg -htrvxdg -g bootdg rmdisk rootdisk02vxdiskunsetup clt15dOwhere cl t15dO is the disk used as the alternate boot disk.

18 Take the system to single user mode by executing ini t l.

init 1

19 Create a copy of the system disk on an LVM disk using thevxre s_1 vmroot command. Do not make the LVM disk the primary bootdisk.

vxres Ivmroot -v clt15dOsetboot

20 Reboot your system using shutdown - ry nowand interrupt the automaticboot process.shutdown -ry nowPressany key to interrupt the boot processwhen the following messagesappear:Processor is booting from first available device.To discontinue, press any key within 10 seconds.You should see"Boot terminated." messagefollowed by the Main menu.


Main Menu: Enter command or menu> bo alt

Lab 3 Solutions: Encapsulation and Rootability B-47COpyright ~t;2006 Svmamec Coroorat.oo. All fights reservec

Interact with IPL (Y, N, or Cancel)? n

22 When the system is up, verify that the system is booted on the l.VM disk byexecuting the bdf command, und display the file system table and the/ stand/bootconf lilc.bdfcat /etc/fstab (includes LV:\! volumes for system disk file systems)cat /stand/bootconf (shows the LV'. disk as the boot device)

23 Reboot your system using shutdown - ry now and when the system isback up verify that the system is booted 011V.xVM volumes, and display thefile system table and the / stand/bootconf fi Ie.

shutdown -ry nowAfter the system is back up, login as root.

bdfcat /etc/fstab (includes \"x"l volumes for system disk file systems)cat /stand/bootconf (shows the VxV\,! disk as the boot device)

LVM to VxVM Conversion - HP-UX

Create two LVM physical volumes using the pvcreate command on twouninuializcd external disks as follows:

pvcreate /dev/rdsk/device taglpvcreate /dev/rdsk/device tag2Note: If you do 1I0t have enough uninitializcd external disks, you may need toun initialize the empty disks that an: under Vx VM control before creating thel.VM physical volumes.

2 Create a volume group called vgO 1 using the physical volumes as follows:

mkdir /dev/vgOlmknod /dev/vgOl/group c 64 Ox020000vgcreate /dev/vgOl /dev/dsk/device_tagl \

/dev/dsk/device_tag2

3 Using the Ivcreate conunund, create two logical volumes, oneconcatenated and one striped, of size 100MB ill the vgOl volume group asfollows: (Use 32K as the stripe unit.)

Ivcreate -L 100 -n concatvoll /dev/vgOlIvcreate -i 2 -I 32 -L 100 -n stripevoll /dev/vgOl

4 Make vxfs file systems 011both \ olumcs and mount them to two newdirectories called /concat and /stripe.mkfs -F vxfs /dev/vgOl/rconcatvoll

8-48 VERITAS Storage Foundation 5.0 for UNIX: MaintenanceCopynyhl j;::, 2006 Svmanlec Comorauon All lights reserved

mkfs -F vxfs /dev/vgOl/rstripevollmkdir /concatmkdir /stripemount -F vxfs /dev/vgOl/concatvoll /concatmount -F vxfs /dev/vgOl/stripevoll /stripe

5 Edit the /etc/fstab file and create the corresponding entries for the tilesystems by adding the following lines:/dev/vgOl/concatvoll /concat vxfs log 0 2/dev/vgOl/stripevoll /stripe vxfs log 0 2vi /etc/fstab

6 Using the vgcfgbackup command. back up the IVM configuration for thevolume group that you created in the first part of the lab.vgcfgbackup -f /vgOlconf vgOl

7 Unmount the file systems and run the conversion tool: vxvmconvert.

umount /concatumount /stripevxvmconvert

a Analyze the LVM volume group (option I) you created in the first part ofthe lab. What is the result of the analysis"Successful.

b Convert the LVM volume group (option 2) to a VxVM disk group nameddgO 1. What changes did you notice in device names'!The volume nameswill be the sameas the LVM volume names.Thedisk ~roup name is specified during the conversion and the disk medianames,subdisk, and plex namesfollow the VxVM naming comentions.

c Quit from the utility.

8 Examine the tile /etc/fstab. and the directories /dev/vgOI and/dev/vx/ l r l dsk. What changes have been made?The entries in /etc/fstab have been modilied, /dev /vgOl is goneandthe volumes are now in /dev/vx/ [rl dsk/dgOl.

9 Change the volume name uf conca tvoll to volO 1 after the conversion.vxedit -g dgOl rename concatvoll volOlChange the corresponding /etc/fstab entry to:/dev/vx/dsk/dgOl/volOl /concat vxfs log 0 2vi /etc/fstab

10 Remount the tile systems.mount -F vxfs /dev/vx/dsk/dgOl/volOl /concat

Lab 3 Solutions: Encapsulation and Rootability B-49

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mount -F vxfs /dev/vx/dsk/dgOl/stripevoll /stripe

11 After the conversion to Yx YM completes successfully. create a Yx VM diskgroup called testdg on another external disk.

vxdisksetup -i device_tag3vxdg init testdg testdgOl=aevice_tag3

12 Unmouut thc file systems and roll back to LVM configuration usingvxvmconvert option 3. What did you observe?

umount /concatumount /stripevxvrnconvertSelectoption 3.Only vgOl is eligible for rollback (not the original VxVi\'! disk grouptestdg).

You are warned that your changeswill he lost. Everything including the/ etc/ fstab record has reverted to the original names.

13 Remove the entries lor Iconcat and /stripe from /etc/fstab.

vi /etc/fstab

14 Using the 1vremove command. remove the volumes concatvoll andstripevoll.

Ivremove /dev/vgOl/concatvollConfirm when prompted.Ivremove /dev/vgOl/stripevollConfirm when prompted.

15 Destroy the volume group vgOl.

vgreduce /dev/vgOl /dev/dsk/device_tag2vgremove /dev/vgOl

16 Convert the empty LVM physical volumes to VxVM by removing them fromLVM control and then initializing them using VxVM.

pvremove /dev/rdsk/device tag1pvremove /dev/rdsk/device_tag2vxdisksetup -i device_tag1vxdisksetup -i device_tag2


vxdg destroy testdg


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symantec.

Lab4


!For Lab Exercises, see Appendix A.l£~rLab Solutions, see Appendix B.

Lab 4 Solutions: Troubleshooting the Boot ProcessIn this lab. you practice recovering from encapsulated boot disk failure scenarios.On the Solaris platform. to investigate and practice recovery techniques. you willLIse a set of interactive lab scripts. Each script simulates a failure in theencapsulated boot disk (and its mirror. ifrequired) and reboots the system.


Prerequisite Setup

To perform this lab, you need a lab system with Storage Foundation pre-installed.configured and licensed. In addition to this. you also need a second internal disk tobe used as an alternative boot disk.

If you have completed the previous labs, you should have the following setup:

On the Solaris platform. you should have your system disk under VxVMcontrol (encapsulated) but not mirrored.

On the IIP-UX platform. you should have the system disk under VxVMcontrol and you should have the second internal disk configured as analternative LVM boot disk.

Note: This lab requires console access. If you arc working in a Virtual Academylab environment with no console access. you cannot perform this lab.

Lab 4 Solutions: Troubleshooting the Boot Process B-51

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Classroom lab Values

In preparation for this lab, you will need thc following information about your labenvironment. For your reference, you may record the information here, or referback to the IiI'S! lab in the SF Fundamentals section where you initiallydocumented this informauon.

Object Sample Value Your '·alucroot password veritas

Host name trainl

Host name of the system train2sharing disks with mysysteml\Iy Bunt Disk: Solaris:cOtOdO

HP-LX:clt15dOAIX: hdiskOLinux: hda

2nd Internal Disk: Solaris: cOt2dO--

HP-LX:c3t15dOAIX: hdiskll.inux: hdb

Location tlf I.ab Scripts: /student/labs/sf/sf 50

8-52 VERITAS Storage Foundation 5.0 for UNIX· Maintenance

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Solaris Only: Troubleshooting the Boot Process

Note: The boot process troubleshooting labs vary by platform due to the way inwhich the boot disk is handled by the operating system. This lab sectionapplies to Solaris only. Labs for IIP-UX arc presented in the next section.

Note: These labs require console access. I I' you arc working in a Virtual Academylab environment with no console access. you cannot perform these labs.

Troubleshooting the Boot Process - Solaris

Overview

Your goal is to recover from the problem as described in each scenario. Use yourknowledge ofVxVM administration. as well as the VxVM recovery tools andconcepts described in the lesson. to determine what steps to take to ensurerecovery. You succeed when you solve the problem with the boot disk and boot tomultiuser mode.

For most of the recovery problems, you can use any of the VxVM interfaces: thecommand line interlace. the VERITAS Enterprise Administrator (VEA) graphicaluser interlace. or the vxdiskadm menu interlace. Lab solutions are provided foronly one method. If you have questions about recovery using interlaces notcovered in the solutions. see your instructor.

Setup

In this lab, the automated lab scripts prompt you to reboot the system. If the rebootfails. ask your instructor how to bring the system down.

If your system is set to use enclosure-based naming. then you must turn offenclosure-based naming before running the lab scripts.

2 These labs require the system disk to be encapsulated. If your system disk isnot encapsulated. you must encapsulate it before proceeding with this lab. Usevxdiskadm to encapsulate the boot disk. Use systemdg as the name of yourboot disk group and use rootdisk as the name of your boot disk.

3 You must have at least one additional disk that is the same size (or larger) asyour boot disk. You arc instructed to create a mirror of the boot disk in thesecond exercise.


B-53Lab 4 Solutions: Troubleshooting the Boot Process

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Recovering from Encapsulated. Unmirrored Boot Disk Failure

In this lab exercise, you attempt to recover lrom encapsulated. unmirrored bootdisk failure. You succeed when you recover the system disk and boot to multiusermode. The lab script run_root simulates a boot disk failure. Ask your instructorlor the location of the run_root script.

This lab requires that the system disk is encapsulated. but not mirrored. I f yoursystem disk is mirrored, then remove the mirror.

2 Save a copy of the / etc/ system file to / etc/ system. preencap. In thenew file (/ etc/ system. preencap). comment out the non-forceloadlines related to VxVM (the lines that define the disk to be an encapsulateddevice).

To comment out a line, place an asterisk (*) in front of the line in the/ etc/ sys tern. preencap file:

* rootdev:/pseudo/vxio@O:O* set vxio:vol rootdev is volume=l

3 From the directory that contains the lab scripts, run the script run_ root, andselect option I. "Encapsulated. uumirrorcd boot disk failure":

Before \'011 Begin: Ensure that tile environment variable DG is set to the nameof the bootdg disk group.echo $DG I I' it is not set, set it before you continue:

DG="bootdg"export DGrun root1) Lab 1 - Encapsulated, unmirrored boot disk failure2) Lab 2 - Encapsulated, mirrored boot disk failure - 13) Optional Lab 3 - Encapsulated, mirrored boot diskfailure - 2x ) ExitYour Choice? 1

4 Follow the instructions in the lab script window. This script causes thc onlyplcx in rootvol to change to the STALE state. When you arc ready. thesystem will be rebooted twice. Wait until the system reboot fails because oftheSTALE plcx and you arc presented with the OK prompt.


C<Jryflq~ll; 2006 Syoiamec Comorano« All rights reserved

5 Recover the volume root vol by using the / etc/ system. preencap tilethat you created before the failure. You succeed when the system boots up tomultiuser mode.

To recover:a When the systemfails tu boot up, usethe commandboot -a from the

ok prompt:ok> boot -a

b PressReturn whenprompted for the UMX and kernel infurmatiun.'Vhen prompted for the nameuf the sys tern file, enter the nameuf thefile that you copiedwith nun-forceload linescommenteduut:Nameof system file [etc/systeml: etc/systern.preencap

c Whenyuu are in maintenancemode,checkthe stateuf rootvol byusingthevxprint command:vxprint -g bootdg -ht

You shouldnoticethat rootvol is nul started (DISABLED mode),andthe only plex it has(rootvol- 01) is STALE.

Note:bootdg is a reservednameand is just a link to whateverdiskgruup you usedwhenyou encapsulatedthesystemdisk. It is nut avariable to be replacedby the nameuf the disk group you are using.

d Tu recover:vxmend -g bootdg fix clean rootvol-Olvxvol -g bootdg start rootvolvxprint -g bootdg -htreboot

Lab 4 Solutions: Troubleshooting the Boot Process B-55Copyright g: 2006 Svmantec Comoranoo All fights .eseveo

Recovering from Encapsulated. Mirrored Boot Disk Failure (1)

In this lab exercise. you attempt to recover from encapsulated. minored boot diskfailure. You succeed when you recover the system disk and boot to multiusermode. The lab script run_root simulates a boot disk failure. Ask your instructorfor the location of the 1un _ root script.

Important: Mirror the boot disk. This lab requires that the system disk isencapsulated and mirrored. I f your system disk is not currently mirrored. thenmirror the system disk before continuing.

Note: Make sure that the use-nvramrc? eeprom parameter is set to truewhen you mirror the system disk. so that the device alias created by VxVM Iorthe mirror disk call be used.

2 If you have not already done so. save a copy of the /etc/system file to/ etc/ system. preencap. In the new file (/ etc/ system. preencap).comment out the non-force load lines related to YxYM (the lines that definethe disk to be an encapsulated device).

To comment out a line. place au asterisk (*) in front or the line in theI e tel system. preeneap file:


3 From the directory that contains the lab scripts. run the script run_root. andselect option 2. "Encapsulated, mirrored boot disk failure - I":

Before '1'011 Begin: Ensure that the environment variable DG is set to the nameof the bootdg disk group.eeho $DG II it is not set. set it before you continue:

DG="bootdg"export DG

run root1) Lab 1 - Encapsulated, unmirrored boot disk failure2) Lab 2 - Encapsulated, mirrored boot disk failure - 13) Optional Lab 3 - Encapsulated, mirrored boot diskfailure - 2x) ExitYour Choice? 2

4 Follow the instructions in the lab script window. This script causes both plcxcsin root vol to change to the STALE state. When you arc ready. the system isrebooted. The system docs not come up due to the STALE plcx.


Cupynqtn '0 2006 Svruantec Corporation AlllIglltS reserved

5 Recover thevolumeroot vol by usingthe / et c / system. pr eeric ap filethat you created before the failure. You succeed when the system boots up tomultiuser mode.To recover:a When the systemfails to boot up. usethe commandboot -a from the

ok prompt:ok boot -a

b PressReturn when prompted for the ll:\IX and kernel information.When prompted for the nameof the sys tern file, enter the nameof thetile that you copiedwith non-forceload linescommentedout:Nameof system file [etc/systeml: etc/systern.preencap

c When you are in maintenancemode.checkthe stateof rootvol byusing the vxprint command:vxprint -g bootdg -ht

You should noticethat rootvol is not started (DISABLED mode),andboth plexes(rootvol- 01 and rootvol- 02) are STALE.

d To recover:vxmend -g bootdg fix clean rootvol-Ol

If you do not want to wait for the mirrors to resynchronizebeforebooting up to multiuser mode,you can offline the secondplex and thencontinue:vxmend -g bootdg off rootvol-02

Otherwise. the staleplex is resynchronizedfrom the cleanplex whenyou start the volume.

e Start the volume rootvol and reboot:vxvol -g bootdg start rootvolrebootNote: While you are rebooting the system,if vuu receivea messagestating that the root file systemcould not be repaired and sbnuld becheckedmanually. enter the maintenancemodeb~ providing the rootpassword,and manually checkthe root tile systemb~ executingthefsck -F ufs /dev/vx/rdsk/bootdg/rootvol command.Once the file systemcheckis complete.reboot the system.

After you boot up to multiuser mode.online the secondplex (ifnecessary)and recover:vxmend -g bootdg on rootvol-02vxrecover

8-57L.ab 4 Solutions: Troubleshooting the 800t Process

Optional Lab Exercises: Solaris OnlyThe next set of lab exercises is optional and may be performed if you have time.These exercises provide additional recovery scenarios for troubleshooting the bootprocess on Solaris.

Optional Lab: Recovering from Encapsulated. Mirrored Boot DiskFailure (2)

In this lab exercise, you attempt to recover from encapsulated, mirrored boot diskfailure. You succeed when you recover the system disk and boot to multiusermode. The lab script run_root simulates a boot disk failure. Ask your instructorfor the location of the run_root script.

Important: :\-1irror the boot disk. This lab requires that the system disk isencapsulated and mirrored. I I' your system disk is not currently mirrored, thenmirror the system disk before continuing. I I' your system disk is alreadymirrored. ensure that all the pines of the system disk vulurncs and the volumesthemselves arc in ENABLED/ACTIVE state, that is there arc nosynchronization processes that arc running on the volumes on the system disk.

"Iote: Make sure that the use- nvramre? eeprom parameter is set to truewhen youmirror the system disk. so thai the device alias creal cd by VxVM It)!'the mirror disk can be used. Run the eeprom command and view the settingsfor deval ias, such as vx - a 1tboot and vx- rootdisk.

2 ltyou have not already done so. save a copy of the jete/system tile to/ ete/ system. preeneap. In the new Iile (/ ete/ system. preeneap),comment out the non-foreeload lines related to VxVM (the lines that definethe disk to be an encapsulated device).

To comment out a line, place an asterisk (*) in front of the line in the/ete/ system. preeneap tile:


3 From the directory that contains the lab scripts, run the script run_root, andselect option 3,"Encapsulated, mirrored boot disk failure - T:Before You Begin: Ensure thai the environment variable DG is set to the nameof the bootdg disk group.

eeho $DG I f it is 110t set. set it before you continue:

DG="bootdg"export DGrun root


COPYright '!;.' 2006 Symaeaec Co-coranoo 1\11fights reser v eo

1) Lab 1 - Encapsulated, unmirrored boot disk failure2) Lab 2 - Encapsulated, mirrored boot disk failure - 13) Optional Lab 3 - Encapsulated, mirrored boot diskfailure - 2x) ExitYour Choice? 3

4 Follow the instructions in the lab script window, This script causes one of theplcxes in root vol to change to the STALE state. The clean plex is missing the/kernel directory. so yuu cannot boot up the system without recovery. Whenyou arc ready. the script reboots the system.

5 Recover the volume root vol by using the / etc/ system. preencap filethat you created before the failure. You succeed when the system boots up tomultiuser mode.

In this lab, the original system disk fails to boot becausethe /kerneldirectory is missing on the rootvol- 01 plex, although the rootvol- 01plex is in a CLEAN state. (This directory has been renamed as/kernel. bak.) The mirror disk fails to boot becausethe secondplex is inSTALE mode.To recover, you must boot up on the mirror disk using the partition ratherthan the volume. For example, assumethat the mirror of the system diskis called sysdg02 and you have already changed the use-nvramrc?parameter to true while you were mirroring the systemdisk so that\'xVM created the devalias vx- sysdg02 for the mirror disk.a Run the following command on the ok prompt to boot up to single-

user mode:ok boot vx-sysdg02 -as

b PressReturn when prompted for the UNIX and kernel information.When prompted for the name of the system file, enter the name of thefile that you copied with non-forceload lines commented out:Name of system file [etc/systeml: etc/system.preencap

c When you are in maintenance mode, check the state of rootvol byusing the vxprint command:vxprint -g bootdg -ht

You should notice that the rootvol is started (ENABLED/ACTIVEmode), the plex rootvol- 01 is ACTIVE, and the piex rootvol- 02 isSTALE. To prevent the second plex from being resyuchronizedautomatically upon reboot, offline the secondplex using:vxmend -g bootdg off rootvol-02

Lab 4 Solutions: Troubleshooting the Boot Process

Copynqnte. 2006 Svmaruec Coeooranoo 1\11fights -esevec

B-59

d To recover using rootvol- 01:

mount -F ufa /dev/vx/dak/bootdg/rootvol /mnt

Note: When you run this command, ityou receiveany errors aboutnot being able to wrlte to /etc/mnttab, then ignore them.

cd /mntmv kernel.bak kernelcd /umount /mntreboot

Note: While you are rebooting the system, if you receive a messagestating that the root fill' systemcould not bc repaired and should bechecked manually, enter thc maintenance mode by providing the rootpassword, and manually check the root tile system by executing thefack -F ufa /dev/vx/rdak/bootdg/rootvol command.Once the file systemcheck is complete, reboot the system.

e Once you boot lip to multiuser mode, online the secondplex andrecover:vxmend -g bootdg on rootvol-02vxrecover

Notes

In a real-world environment, becausethe kernel directory is totallymissing, you must copy it from the partition that YOIl booted lip on (in stepd):

mkdir /mnt/kernelcd /kernel; tar cf - (cd /mnt/kernel; tar xfBp -)

YOII could also recover by using the secondplex rootvol- 02, by oflliningthe first piex rootvol-01 and setting the secondptex rootvol-02 toCLEAN before rebooting, However, if the secondpiex becameSTALEbefore YOII lost the kernel directory on the first plex, this piex does notcontain the most up-to-date data for recovery.

8-60 VERITAS Storage Foundetion 5,0 for UNIX,' Mail1tel1al1ce

Copyroyht t; 2006 Symantec Corpo-encn All nqhts reserved

HP-UX Only: Troubleshooting the Boot Process

Note: The boot process troubleshooting labs vary by platform due to the way inwhich the boot disk is handled by the operating system. This lab sectionapplies to IIP-UX only. Labs for Solaris are presented in the previoussection.

Note: These labs require console access. If you are working in a Virtual Academylab environment with no console access, you cannot perform these labs.

Troubleshooting the Boot Process - HP-UX

Note: Before starting this lab, ensure that the system disk is under VxVM controland that there is an alternate LVM boot disk.

Part IReboot your system using shutdown - ry now and interrupt the automaticboot process.

shutdown -ry nowPress any key to interrupt the boot process when the following messagesappear:Processor is booting from first available device.To discontinue, press any key within 10 seconds.You should see "Boot terminated." message followed by the Mainmenu.


Main Menu: Enter command or menu> bo altInteract with IPL (Y, N, or Cancel)? n

3 When the system is up, verify that the system is booted Oil the LVM disk byexecuting the bdf command. Ensure that the systemdg disk group that isused fur the VxVM boot disk is imported on the system.

bdfvxdg list

4 Stop the rootvol volume and change the state of the only plcx in therootvol volume tu STALE using the vxmend fix stale command.

vxvol -g systemdg stop rootvol

Lab 4 Solutions: Troubleshooting the 800t Process 8-61Copyr.qnt f 2006 Svmantec Corporauon All nqtus reserved

vxmend -g systemdg fix stale rootvol-Ol

5 Reboot your system using shutdown - ry now. 00 not interrupt the bootprocess. Observe what happens.

Systemis halted when the boot processattempts to start the root volume.

6 Recover the YxYM boot disk using the maintenance mode boot withoutbooting olf the LYM system disk.CTRL-B

Service Processor login: <CR> (if necessary)Service Processor password: <CR> (if necessary)

GSP> rs

Type Y to confirm your intention to restart the system:(Y/ [N]) y

GSP> co

Pressany key to interrupt the boot processwhen the following messagesappear:Processor is booting from first available device.To discontinue, press any key within 10 seconds.You should see"Boot terminated." messagefollowed by the Mainmenu.Main Menu: Enter command or menu> bo priInteract with IPL (Y, N, or Cancel)? y

ISL> hpux -vmVxVM Maintenance Mode boot

INIT: SINGLE USER MODEINIT: Running /sbin/shvx_emerg start nodenamevxdctl modevxdg listvxprint -g systemdg -htrvxmend -g systemdg fix clean rootvol-Olvxvol -g systemdg start rootvolvxprint -g systemdg -htrshutdown -ry nowNore: Ignore any error messagesrelated 10 shutdown scripts.


C()f)yn\jtl!( 2006 Svmantec Corporatron All «cnts reserved

Part II1 Ensure that you are booted off the VxVM system disk using the bdf

command. Edit the /etc/vx/volboot file and modify the hostid entry todummy.

bdfvi /etc/vx/volboot

hostid dununy

(save and quit)

2 Reboot your system using shutdown - ry now. Do not interrupt the bootprocess. Observe what happens.

System is halted after vxconfigd is started in boot 1II0de. An errormessage indicates that there is a mismatch with the volboot tile.

3 Recover the Vx VM boot disk using the maintenance mode boot withoutbooting offthe LVM system disk.

CTRL-BService Processor login: <CR> (if necessary)Service Processor password: <CR> (if necessary)

GSP> rs

Type Y to confirm your intention to restart the system:(Y/ [N]) y

GSP> coPress any key to interrupt the boot process when the following messagesappear:

Processor is booting from first available device.To discontinue, press any key within 10 seconds.You should see "Boot terminated." message followed by the Main menu.

Main Menu: Enter command or menu> be priInteract with IPL (Y, N, or Cancel)? y

ISL> hpux -vmVxVM Maintenance Mode boot

INIT: SINGLE USER MODEINIT: Running /sbin/shcat /etc/vx/velbeetvx_emerg start nodename

B-63Lab 4 Solutions: Troubleshooting the Boot Process

Copvnqht 'f 2006 Swnantar Corporauon All nqhts reserven

You should see messages indicating that the mismatch is corrected.cat /etc/vx/volbootshutdown -ry now

Note: Ignore any error messages related to shutdown scripts.

4 When the system comes back up verify that you are running 011 the YxVMboot disk. Destroy the LVM boot disk on the other internal disk to free up theinternal disk lor later labs.bdfvxdestroy_lvmroot -v clt15dO

vxdisk -0 alldgs list (you should see the second internal disk as anuninitialized disk ready 10 be used)


Copyrlynl s. 2006 Syrnantec Corporation All fights reserved

symantcc.

Lab 5

Lab 5: Volume MaintenanceIn this lab, you practice volume maintenanceactivities, such as changing volume layoutsand using the Storage Expert utility.Optional exercises provide additional practiceon managing VxVM tasks.

u------~~For Lab Exercises, see Appendix A.For Lab Solutions, see Appendix B.

Lab 5 Solutions: Volume MaintenanceIn this lab. you practice volume maintenance activities. such as changing volumelayouts and using the Storage Expert utility. Optional exercises provide additionalpractice on managing VxVM tasks.

The Lab Exercises for this lab arc located on the following page:

Prerequisite Setup

To perform this lab. you need a lab system with Storage Foundation pre-installed.configured and licensed. In addition to this. you also need at least four disks to beused in a disk group.

Lab 5 Solutions: Volume Maintenance

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B-65


In preparation fix this lab, you will need the following information about your labenvironment. For your reference, you may record the information here, or referback to the: first lab in the: SF Fundamentals section where you initiallydocumented this intorm.uion.

Object Sample Value Your Valuemnt password veritas

------- --Hust name trainl

!\I,v Data Disks: Sola r is: clt#dO -clt#d5

HP-UX: c4 t ud o -c4tOd5

AIX: hdisk21-hdisk26

Linux: sda - sdf


CopYW)hl c 2006 svma-uec Ctxporat.on 1\11 flytlls reserved


You can useeither the YEA interfaceor the command line interface,whicheveryou prefer.The solutions for both methodsarecoveredwhereappropriate.If youuseobject namesother than the onesprovided. substitutethe namesaccordingly inthe commands.

Note: If you are using YEA, view the propertiesof the related taskafter eachstepto view the underlying commandthat was issued.

Createa disk group called namedg with four disks.vxdisksetup -i device_tag (itnccessarv)vxdg init namedg namedgOl=device_tagl

namedg02=device_tag2 namedg03=device_tagJnamedg04=device_tag4

2 Createa 20-M13 concatenatedmirrored volume called namevoll. CreateaVeritastile systemon the volume and mount it to /namel. If you useVEA tocreateandmount the tile system.ensurethat the tile systemis not addedto theti Ie systemtable.

YEA

a Highlight the disk group, and select Actions->:\ew Volume.b Specify the volume name, the size,a concatenated layout, and select

mirrored.c Ensure that "Enable logging" is not checked.d Add a VxFS file system and set the mount point.e Uncheck the Add to file system table option and complete the wizard.

eLl

vxassist -g namedg make ·namevoll 20m layout=mirrormkfs -F vxfs /dev/vx/rdsk/namedg/namevoll

Note: On Linux, usemkfs -tomkdir /namel (ifit doesn'talreadyexist.)mount -F vxfs /dev/vx/dsk/namedg/namevoll /namel

3 Add data to the volume and verify that the tile hasbeenadded.echo "hello name" > /namel/hellocat /namel/hello

4 Changethe volume layout from its current layout (mirrored) to a nonlayeredmirror-stripe with two columns anda stripe unit sizeof 1211sectors(04K).

6-67Lab 5 Solutions: Volume Maintenance

Copyrlght'E 2006 Symautec Corporation 1\11nqhts, reserved

Monitor the progress or the rclayout operation, and display the volume layoutafter each command that you run.

VEA

a Highlight the volume and select Actions->Change Layout.

b In the Change Volume Layout dialog box, select a Striped layout,specify two columns, and click OK.

c To monitor the progress of the relayout, the Relayout status monitorwindow is automatically displayed when you start the relayouroperation.

d View the task properties of the relayout operation. Notice that twocommands are issued:

vxassist -t taskid -g namedg relayout namevoll \layout=mirror-stripe nmirror=2 ncol=2stripeunit=128

vxassist -g namedg convert namevoll \layout=mirror-stripe

ell

a To begin the relayour operation:

vxassist -g namedg relayout namevoll \layout=mirror-stripe ncol=2 stripeunit=128

b To monitor the progress of the task, run:vxtask monitor

c Run vxprint to display the volume layout. Notice that a layeredlayout is created:

vxprint -g namedg -rth

d Recall that when you relayuut a volume to a striped layout, a layeredlayout is created first, then )'OU IIIUst use vxassist convert tocomplete the conversion to a nunlayered mirror-stripe:vxassist -g namedg convert namevoll \

layout=mirror-stripe

e Run vxprint to confirm the resulting layout. Notice that the volumeis now a nuulayered volume:

vxprint -g namedg -rth

5 Verily that the file is still accessible.cat /namel/hello


6 Unmount the tile system 011 the volume and remove the volume.

YEA

a llighlight the volume, and select Actions->Delete Volume.

b In the Delete Volume dialog box, click Yes.

c In the Unmount File System dialog box, click Yes.

eLl

umount /namelvxassist -g namedg remove volume namevoll

Using the Storage Expert Utility

Add the directory containing the Storage Expert rules to your PATHenvironment variable in your .profile tile.

PATH=$PATH:/opt/VRTS/vxse/vxvmexport PATH

2 Display a description of Storage Expen rule vxse_drll. What does this ruledo')

vxse drll infoThis rule checks for large mirrored volumes that do not have anassociated log.

3 Does Storage Expert rule vxse _drll have any user-sctrable parameters')

vxse drll list

4 From the command line. create a IOO-MB mirrored volume with no log callednamevoll in the namedg disk group. Create a file system on the volume andmount it to /namel.vxassist -g namedg make namevoll 100m layout=mirrormkfs -F vxfs /dev/vx/rdsk/namedg/namevoll

Note: On Linux, usemkfs -tomkdir /namel (if it docsnot already exist)mount -F vxfs /dev/vx/dsk/namedg/namevoll /namel

5 Run Storage Expert rule vxse_drll 011 the disk group containing the volume.What does Storage Expert report'!

vxse drll -g namedg run

Lab 5 Solutions: Volume Maintenance 8-69Copynqht t; 200ti Swnantec Corporanon 1\11nqnts reserved

Storage Expert reports information; the mirrored volume is skippedbecausethe volume is lessthan the sizeof volumes tested by the rule.

6 Expand the volume to a size of I CiB.vxresize -g namedg namevoll 19

7 Run Storage Expert rule vxse_drll again on the disk group containing thevolume. What does Storage Expert report"vxse drll -g namedg run

Storage Expert reports a violation becausethe large mirrored volumedocsnot have a log.

8 Add a log to the volume.vxassist -g namedg addlog namevoll

9 Run Storage Expert rule vxse_drll again on the disk group containing thcvolume. What docs Storage Expert report'!vxse drll -g namedg runStorage Expert reports that the volume passesthe test, since the largemirrored volume now hasa log.

10 What arc the attributes and parameters that Storage Expert uses in running thevxse drll rule"vxse drll listThe attribute is mirror_threshold. Storage Expert will warn if a mirror isgreater than this sizeand the volume doesnot have a log.vxse drll checkThe mirror_threshold is a I-GB mirrored volume.

11 Shrink the volume to 100 MB and remove the log.vxresize -g namedg namevoll 100mvxassist -g namedg remove log namevoll

12 Run Storage ExpCI1rule vxse_drll again. When running the rule, specifythat you want Storage Expert to test the mirrored volume against amirror_threshold of 1001\,18. What docs Storage Expert report'!vxse drll -g namedg run mirror threshold=lOOmThis step demonstrates how to specify different attribute values from thecommand line. Becauseyou set the mirror_threshold parameter to 100"IB, Storage Expert reports a violation.

13 Unmount the tile system and remove the volume used in this exercise.umount /namelvxassist -g namedg remove volume namevoll


Copyright' 2000 Svrnantec Corporation All rt'Jnts reserved

Optional Lab ExercisesThe next set of lab exercises is optional and may be performed if you have time.These exercises provide additional practice on monitoring tasks.

Optional Lab: Monitoring Tasks

In this optional lab, you track volume rclayout processes using the vxtaskcommand and recover from avxrelayout crash by using VEA or from thecommand line.To begin, you should have at least four disks in the disk group that you are using.

Create a mirror-stripe volume called namevoll in the namedg disk group,with a size of I GB using the vxassist command. Assign a task tag to thetask and run the vxassist cornmaud in the background.

VEA

a Highlight a disk group and select Actlons=c-New Volume,b Specify the volume name, the size, a striped layout, and select

mirrored.c Ensure that ";'1;0 layered volumes" is checked,Note: You cannot assign a task tag when using VEA.

CLI

vxassist -g namedg -b -t task name make namevoll 19 \layout=mirror-stripe

2 View the progress of the task.

YEA

Click the Tasks tab at the bottom of the main window to display the taskand the percent complete.

CLI

vxtask list task nameorvxtask monitor

8-71Lab 5 Sotutions: Votume Maintenance

C0pynghl"'::2006 Symant••c Cocro-auoo Ail ngh\5reserved

3 Slow down the task progress rate to insert an 1/0 delay of 100 milliseconds.

VEA

a Right-click the task in the Tasks tab, and select Throttle Task.b Specify 100 as the Throttling value, and click OK.

CLl

vxtask set slow=lOO task name


4 After the volume has been created. use vxassist to relayout the volume tostripe-mirror. Use a stripe unit size of 256K, use two columns, and assign theprocess to the above task tag.

VEA

a Highlight the volume and select Actions->Change Layout.b In the Change Volume Layout dialog box. select a Striped Mirrored

layout.

c Change the stripe unit size value to 512 on Solaris,256 on HP-UX.

eLl

vxassist -g namedg -t task_name relayout namevoll \layout=stripe-mirror stripeunit=256k ncol=2

5 In another terminal window. abort the task to simulate a crash during rclayout.

VEA

In the Rclayour status monitor window, click Abort.

CLI

vxtask abort task name


6 Reverse the rclayout operation, View the layout ofthe volume alter thereversal of the rcluyout operation completes, Notice that the stripe unit size is


back to the original value but the layout is layered. Change the layout to 110n-layered.

YEA

In the Relayout status monitor window, click Reverse.

eLl

vxrelayout -g namedg reverse namevollView the layout of the volume in the VEA interface.vxassist -g namedg convert namevoll \

layout=mirror-stripe


YEA

a Select the Disk Groups node in the object tree and the namedg diskgroup in the right pane dew.

b SelectActlons=c-Dcstroy Disk Group.e Confirm when prompted.

CLI

vxdg destroy namedg

B-73Lab 5 Solutions: Volume Maintenance

Copynqhtf 2006 Symantec Corcoranon All fights reserved


Copyflgh\ 1';.2006 Syrnantec Corporation MI fl(:lh!S reserved

Lab 6

Lab 6: Performance MonitoringIn this lab, you analyze Volume Manager 110operations using the vxstat and the vxtraceutilities.

--------------------------,For Lab Exercises, see Appendix A.For Lab Solutions, see Append~B.

symantec.

Lab 6 Solutions: Performance MonitoringThe purpose of this lab is to analyze Volume Manager I/O operations using thevxstat and the vxtrace utilities.


Prerequisite SetupTo perform this lab. you need a lab system with Storage Foundation pre-installed.configured and licensed. In addition to this, you also need at least six disks to beused in a disk group.

Lab 6 Solutions: Performance Monitoring

Copynqnt 'f 2006 Symantec Corooral,on 1\11rights reserved

8-75


In preparation lor this lab, you will need the following information about your labcnvironmcnt. For your reference, you may record the information here, or referback to the first lab in the SF Fundamentals section where you initiallydocumented this information.

Not!': On the HP-UX platform. if you have moved the boot disk from an L VMdisk to a VxVM disk during Encapsulation and Rootability lab (lab 3) or theTroubleshooting the 1300tProcess lab (lab 4), your boot disk and second internaldisk values will have changed Irom previous labs. If you have skipped these labs,the values will still be the same, Ensure that you enter the COITertvalues in thefollowing table.

Ohjl'ct Sample Value Your "aluer-;:OOI password veritas

Hust name trainl

I\ly B'lOt Disk: Solaris: cOtOdO

HP-L'X: c It lSdO

AIX: hdiskO

l.inux: hda2nd Internal Disk: Solaris: cOt2dO

HP-L'X: c3tlSdO

AIX: hdiskl

Linux: hdbMy Data Disks: Solaris: c 1t#dO -

c1t#dS

HP-l:X c4tOdO -c4tOd5

AIX: hdisk21-hdisk26

tinux: sda - sd£Location of Lab Scripts /student/labs/s£!(if any): s£SO

Location of the fp /student/labs/s£/prog ru m: s£SO/bin

8-76 Education and SRT FrameMaker Template Set

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Preparing the Environment for the Performance Labs

If the second internal disk on your system is used in the systemdg disk group,which is the disk group used for the system disk encapsulation, use the followingsteps to free it up for performance testing.

Ifyou do not have a second internal disk or if you cannot use the second internaldisk, skip this section.

If the system disk is encapsulated and mirrored to the second internal disk,remove the mirrors on the second internal disk for all system disk volumes.

YEA

For each volume in bootdg, remove all of the mirrors that use the secondinternal disk. More specifically, for each volume, two plexes are displayed,and you should remove the newer (-02) plexes from each volume.

To remove a mirror. highlight a volume and seleclAClions->Mirror->Remon·.

ell

vxassist -g bootdg remove mirror rootvol !altboot

vxassist -g bootdg remove mirror swapvol !altbootvxassist -g bootdg remove mirror usr !altbootvxassist -g bootdg remove mirror var !altbootwhere a1 tboot is the disk media name used for the mirror of the systemdisk.

2 Remove the second internal disk from the systemdg disk group.

YEA

a Select the systemdg disk group and highlight the empty secondinternal disk.

b Select Actions->Remove Disk From Disk Group.

eLl

vxdg -g systemdg rmdisk altbootwhere a1 tboot is the disk media name used for the second internal diskduring the mirroring of the system disk.

Note: If you are working on the lIP-UX platform and the second internal disk isconfigured as an alternative LVM boot disk. ensure that you arc booted off theVxVM boot disk and destroy the LVM boot disk using the following command:

8-77Lab 6 Solutions: Performance Monitoring

Copvnqht 'f· 2006 Symantac Corrorancn 1\11rights reserved

vxdestroy Ivmroot -v c#t#d#

where c#t#d# is the second internal disk used as an alternative LVM boot disk.

Exploring the vxstat Utility

In this exercise, you analyze the performance ola disk in the testdg disk groupfor 32K random reads. You use the fp program to generate an J!O load. Ask yourinstructor lor the location of the fp program.

Create a non-CDS disk group named testdg that contains one disk. I I' yoursystem has two internal disks and the second internal disk is available for youto use. use the second internal disk. otherwise use any disk except lor yourboot disk. Name the disk testdg01.

Note: In a North American Mobile Academy lab environment. you cannot usethe second uucmal disk during the labs even if the system has a second internaldisk.

Solaris vxdisksetup -i device_tag format=sliced (ifnecessary)vxdg init testdg testdg01=device_tag cds=offwhere device _ tag is c#t#d# for Solaris.

HP-l!X vxdisksetup -i device_tag format=hpdisk (ifnecessary)vxdg init testdg testdg01=device_tag cds=offwhere device_tag is c#t#d# tell HP-UX.

2 Determine the maximum volume size that can be created using thc singledrive. Create a volume named test in the testdg disk group that is themaximum size on the single drive.

vxassist -g testdg maxsize testdg01Maximum volume size: 4151296 (2027Mb)vxassist -g testdg make test 4.251296 testdg01Nore that the volume size may be different in your environment.

3 Invoke the vxstat command to begin drive analysis on the test volume. Setthe vxstat interval to display staristics every I second. Statistics will beginprinting every second. and all statistics arc displayed as 0 until you beginsending I/O to the volume.

Note: To be able to analyze the output later. you can direct it to a file, forexample /tl1lp/vxstat. out.

vxstat -g testdg -i 1 -d test I tee -a /tmp/vxstat.out

B-78 Education and SRT FrameMaker Template Set

Cnpyng~lt ;:: 200€ Syrnantec Coroorahun All fights reserved

4 In a different terminal window, change to the directory that contains the fpprogram.'\'ote: Make sure that you are using the correct version of the fp program foryour platform, for example, f p _ sun for Solaris, fp _ hp for IIP-UX, orfp Linux for l.inux .

Display a description of the fp program by running the fp command withoutany parameters:

cd /location_of_fp./fp platformusage - fileperf path ksize iosize iocnt op [op ... J

path = pathname of file or device on which to run testksize = size of test file to create in units of K bytesiosize = size in Kbytes of each I/O operationiocn = number of times to perform each operationop = [sr sw rr rwJ

The operations supported are:sr sequential readsw sequential writerr random readrw random write

Fileperf creates a file of ksize*lK bytes and performsiocnt operations of size iosize*lK against the file. Ifthe file exists and is at least ksize*lK bytes in size orif a device is specified for path then the create isskipped.

5 From the directory that contains the fp 110 program. start several invocationsof the fp program by using the command:

/location_of_fp/fp_platform /dev/vx/rdsk/testdg/test \2075648 32 4096 rw &

1\otl' that 2075648 is the size of the volume in KB and this commandgl'neratl's random writes of 32K to the volume.

Note: Alternatively, you can use the vi editor to create a simple script thatcontains ten or more invocations of this fp command. This method can moreeffectively flood the volume with 110:

a Invoke the vi editor and create a file named /tmp/testscript.

vi /tmp/testscriptb Copy the fp command shown above into the tile ten or more times.

i

(Type the fp command shown above and copy it multiple times in thefile.)

c Save the test script file.

Lab 6 Solutions: Performance Monitoring B-79Copyright If; 2006 Svmanter Coroorauon All fights reserven

[Ese]:wq

d Change the permissions on the 11k to be readable and writable by the motuser.

ehmod 755 /tmp/testseripte Run the test script.

/tmp/testseript

6 When you execute the fp command or your lest script, the vxstat output inthe other terminal window begins to display data. Wait for all the fpcommands or the script to finish executing, then stop the vxstat output bytyping CTRL-C on the terminal you arc running vxstat, and analyze thevxstat output and determine the peak performance of the drive.

Peak drive performance is reached when the number of 1/0 operationsand the 1/0 count stop increasing on the vxstat output.


vxdg destroy testdg


COnynghl1;:· 2006 Svmantec Corporation All ny!Jts reserved

Optional Lab ExercisesThe next set of lab exercises is optional and may be performed if you have time.These exercises provide additional performance scenarios for exploringperformance utilities.

Optional Lab: Analyzing Drive Performance: Scenarios

In this exercise. you analyze drive performance based on sample vxstat outputand identify possible improvements to volume layouts. This exercise is theoretical.but designed to help you understand how tu interpret vxstat output.

Note: The samples provided arc from a Solaris platform. Therefore I block isequivalent to 512 bytes.

Scenario I

Suppose that you have a disk group named testdg that contains four disks. Youhave a IOO-MU volume. called test. striped across two disks with a stripe unitsize of 4 MB. There are three processes performing random reads that arc 512K insize on the volume. There are no other volumes in the disk group.

When you run a performance test and run vxstat on the disk group, thefollowing output is displayed:

vxstat -g testdg -d

OPERATIONS BLOCKS AVG TIME(ms)TYP NAME READ WRITE READ WRITE READ WRITEdm testdg01 107 0 109568 0 50.9 0.0dm testdg02 91 93184 a 42.5 0.0dm testdg03 a a a 0.0 0.0dm testdg04 a a a O. a 0.0

Analyze the vxstat output. What do you notice"You have a bottlenecked drive. l\Iost of the 1/0 operations are going to asingle drive.

2 What changes might you make to the volume layout to improve performance"Because there are additional disks in the disk group that are not used forany other volumes, you can improve the performauce b~' increasing thenumher of columns:vxassist -g testdg relayeut test neel=3When you rerun the performance test, you would expect the vxstatoutput to look similar to:vxstat -g testdg -d

Lab 6 Solutions: Performance Monitoring 8-81Copynoht '!': 2006 Symautec Ccmoranon All nqms reserved

OPERATIONS BLOCKS AVG TIME (ms)TYP NAME READ WRITE READ WRITE READ WRITEdm testdg01 80 0 81920 0 46.4 0.0dm testdg02 64 0 65536 0 45.6 0.0dm testdg03 54 0 55296 0 39.6 0.0dm testdg04 0 0 0 0 0.0 0.0

Scenario 2

Suppose that you have a disk group named testdg that contains four disks. Youhave a IOO-MB volume. called test. that is concatenated using two disks. Therean: three processes performing random reads of size 512K on the volume. Therearc no other volumes in the disk group.

When you run a performance test ami run vxstat on thc disk group. thefollowing output is displayed:

vxstat -g testdg -d

OPERATIONS BLOCKS AVG TIME(ms)TYP NAME READ WRITE READ WRITE READ WRITEdm testdg01 165 0 168960 0 57.5 0.0dm testdg02 36 0 36864 0 24.7 0.0dm testdg03 0 0 0 0 0.0 0.0dm testdg04 0 0 0 0 0.0 0.0

Analyze the vxstat output. What do you notice"

Notice that most of the 1/0 is concentrated on the first disk in theconcatenated volume. lhcre is no 1/0 on the other disks in the disk group.

2 What changes niighr you make to the volume layout to improve performance'!

To improve the performance, balance the load across the disks in the diskgroup by changing the layout from concatenated to striped:

vxassist -g testdg relayout test layout=stripe neol=3stripeunit=4m

When you rerun the performance test, )OU would expect the vxstatoutput to look similar to:vxstat -g testdg -d

OPERATIONS BLOCKS AVG TIME (ms )TYP NAME READ WRITE READ WRITE READ WRITEdm testdg01 63 0 64512 0 46.5 0.0dm testdg02 0 0 0.0 0.0dm testdg03 79 80896 0 46.6 0.0dm testdg04 56 0 57344 0 39.5 0.0


Cupyrl>jhl t, 2006 Svn.antec Corporanou All r1gt'b reservec

Scenario 3

Suppose that you have a disk group named t estdg that contains four disks. Youhave two volumes:

A IOO-MB volume called test striped across three disks with a stripe unitsize of4 MBAnother IOO-MB volume called test2 with a concatenated layout on the disktestdgOl. which is also one orthe disks used by the volume test.

There are three processes performing random reads of size InK on the testvolume and one process performing random reads of size 512Kon the test2volume.

When you I1I1l a performance test and run vxstat on the disk group, thefollowing output is displayed:vxstat -g testdg -d

OPERATIONS BLOCKS AVG TIME(ms)TYP NAME READ WRITE READ WRITE READ WRITEdm testdg01 241 0 13 84 9 6 0 30.8 0.0dm testdg02 126 0 32256 17.6 0.0dm testdg03 132 33792 0 18.2 0.0dm testdg04 0 0 0 0.0 0.0

Analyze the vxstat output. What do you notice'!Notice that the disk that has two volumes has a much higher number of1/0 operations and a slower responsetime than the other disks.

2 What changes might you make to the volume layout to improve performance')You can improve performance by moving one of the volumes off of thatdisk:vxassist -g testdg move test2 !testdg01 testdg04

\Vhen you rerun the performance test, you would expect the vxstatoutput to look similar to:vxstat -g testdg -d

OPERATIONS BLOCKS AVG TIME (ms )TYP NAME READ WRITE READ WRITE READ WRITEdm testdg01 128 0 32768 0 23.0 0.0dm testdg02 124 0 31744 24.3 0.0dm testdg03 147 0 37632 0 24.7 0.0dm testdg04 100 0 102400 25.5 0.0

Lab 6 Solutions: Performance Monitoring 8-83Copynqtu". 2006 Symnntec C()rpn(;'1i'OJI All nqhts reserved

Optional Lab: Analyzing the Application 1/0 Profile: Scenarios

In this exercise. you analyze the application I/O profile based on sample vxtraceoutput and identi fy possible improvements to volume layouts (for example.changing the layout from concatenated to striped, increasing the number ofcolumns. changing the stripe unit size. and so on). This exercise is theoretical, butdesigned to help you understand how to interpret vxtrace output.

Note: The samples provided arc Irorn a Solaris platform. Therefore I block isequivalent to 51~ bytes."

Scenario I

Suppose that you have a disk group named testdg that contains four disks. Youhave a IOO-MBvolume. namedtest. striped across two disks v. ith a stripc unitsize of4K.

When you start a trace on the volume. run a performance test on the volume, andthen stop the trace on the volume. the following vxtrace output is displayed:

vxtrace -g testdg -d /tmp/appiolabl.out -0 dev,disk testICtrl+CJ

vxtrace -g testdg -f /tmp/appiolabl.out -0 dev,disk I pg

3601 START write vdev test block 115392 len 64 concurrency 1 pid 69483602 START write disk clt8dOs2 op 3601 block 57696 len 83603 START write disk c1t9dOs2 op 3601 block 57696 len3604 START write disk c1t8dOs2 op 3601 block 57704 len 83605 START write disk c1t9dOs2 op 3601 block 57704 len 83606 START write disk c1t8dOs2 op 3601 block 57712 len3607 START write disk c1t9dOs2 op 3601 block 57712 1en 83608 START write disk clt8dOs2 op 3601 block 57720 len 83609 START write disk c1t9dOs2 op 3601 block 57720 len3602 END write disk c1t8dOs2 op 3601 block 57696 len 8 time 03603 END write disk c1t9dOs2 op 3601 block 57696 1en 8 time 03604 END write disk c1t8dOs2 op 3601 block 57704 len 8 time 13606 END write disk c1t8dOs2 op 3601 block 57712 1en 8 time 13608 END write disk clt8dOs2 op 3601 block 57720 len 8 time 13605 END write disk c1t9dOs2 op 3601 block 57704 len time 13607 END write disk c1t9dOs2 op 3601 block 57712 len time 13609 END write disk clt9dOs2 op 3601 block 57720 len time 13601 END write vdev test op 3601 block 115392 len 64 time 1

Analyze thc application 10 profile based on the vxtrace output. Analyze thenumber of concurrent processes, the application I/O size far each process, andwhether the process is performing random or sequential I/O. What do younotice')

There is a single processperforming random writes of size32K IIn thevolume. \'xV'1 must perform four writes to each disk to complete a singleI/O due to the small stripe unit size.

8-84 Education and SRT FrameMaker Template SetCop~n9111 \:; 2006 Svruantec Corpo-anoo Ail nqhts reservec

2 What changes might you make to the volume layout to improve performance"To improve performance, increase the stripe unit size to 16K:vxassist -g testdg relayout test stripeunit=16k

Scenario 2

Suppose that you have a disk group named testdg that contains four disks, Youhave a I OO-MB concatenated volume, named test, on one of the disks,

When you start a trace on the volume, run a performance test on the volume, andthen stop the trace on the volume, the following vxtrace output is displayed:vxtrace -g testdg -d /tmp/appiolab2.out -0 dev,disk test

ICtrl+CIvxtrace -g testdg -f /tmp/appiolab2.out -0 dev,disk I pg

6005 START read vdev test block 108256 len 32 concurrency 2 pid 72116006 START read disk c1t8dOs2 op 6005 block 108256 len 326007 START read vdev test block 59552 len 32 concurrency 3 pid 72176008 START read disk c1t8dOs2 op 6007 block 59552 len 326004 END read disk c1t8dOs2 op 6003 block 172512 len 32 time 16003 END read vdev test op 6003 block 172512 len 32 time 16009 START read vdev test block 196352 len 32 concurrency 3 pid 72146010 START read disk c1t8dOs2 op 6009 block 196352 len 326008 END read disk c1t8dOs2 op 6007 block 59552 len 32 time6007 END read vdev test op 6007 block 59552 len 32 time 16011 START read vdev test block 78688 len 32 concurrency 3 pid 72176012 START read disk c1t8dOs2 op 6011 block 78688 len 326010 END read disk c1t8dOs2 op 6009 block 196352 len 32 time 06009 END read vdev test op 6009 block 196352 1en 32 time 06013 START read vdev test block 151712 len 32 concurrency 3 pid 72146014 START read disk c1t8dOs2 op 6013 block 151712 len 326006 END read disk c1t8dOs2 op 6005 block 108256 len 32 time 26005 END read vdev test op 6005 block 108256 len 32 time 2

Analyze the application I/O profile basedon the vxtrace output. Analyze thenumber of concurrent processes, the application I/O size for each process, andwhether the process is performing random or sequential I/O, What do younotice"There are three processesperforming random reads of size 16K on thevolume.

2 What changes might you make to the volume layout to improve performance"To improve performance, change the layout to striped with at least threecolumns and a large stripe unit size:vxassist -g testdg relayout test layout=stripe ncol=3 \stripeunit=256kORvxassist -g testdg relayout test ncol=4 stripeunit=8k

Lab 6 Solutions: Performance Monitoring 8-85Copyright 1);' 2006 Symantec Corpora lion All rights reserved

Scenario 3

Suppose that you have a disk group named testdg that contains four disks. Youhave a IOO-MB volumcc narncd test, striped across three disk> with a stripe unitsize of4K.

When you start a truce on the volume. run a performance test on the volume. andthen stop the trace on the volume. the following vxtrace output is displayed:


ICtrl+C1


6802 START read vdev test block 194304 len 64 concurrency 2 pid 74876803 START read disk c1t8dOs2 op 6802 block 64768 len 86804 START read disk c1t9dOs2 op 6802 block 64768 len 86805 START read disk clt10dOs2 op 6802 block 64768 len 86806 START read disk clt8dOs2 op 6802 block 64776 len 86807 START read disk clt9dOs2 op 6802 block 64776 len B6808 START read disk cltl0dOs2 op 6802 block 64776 len 86809 START read disk clt8dOs2 op 6802 block 64784 len 86810 START read disk clt9dOs2 op 6802 block 64784 len 86795 END read disk clt9dOs2 op 6793 block 67712 len 8 time 16798 END read disk clt9dOs2 op 6793 block 67720 len 8 time 16801 END read disk clt9dOs2 op 6793 block 67728 len 8 time 16794 END read disk cltBdOs2 op 6793 block 67712 len 8 time 16797 END read disk clt8dOs2 op 6793 block 67720 len 8 time 16800 END read disk clt8dOs2 op 6793 block 67728 len time 16796 END read disk c1t10dOs2 op 6793 block 67712 len 8 time 26799 END read disk c1t10dOs2 op 6793 block 67720 len 8 time 26793 END read vdev test op 6793 block 203136 len 64 time 26811 START read vdev test block 169984 len 64 concurrency 2 pid 74846812 START read disk cltl0dOs2 op 6811 block 56656 len 86813 START read disk cltBdOs2 op 6811 block 56664 len 86814 START read disk clt9dOs2 op 6811 block 56664 len 86815 START read disk cltl0dOs2 op 6811 block 56664 len 86816 START read disk cltBdOs2 op 6811 block 56672 len 86817 START read disk clt9dOs2 op 6811 block 56672 len 86818 START read disk cltl0dOs2 op 6811 block 56672 len B6819 START read disk clt8dOs2 op 6811 block 56680 len 86820 START read vdev test block 32320 len 64 concurrency 3 pid 7490

Analyze the application 1'0 profile based on the vxtrace output. Analyze thenumber or concurrent processes, the application I/O size tor each process, andwhether the process is performing random or sequential 1.'0. What do younotice?

There are three processesperfurmlng random reads of size32K on thevolume.

2 What changes might you make to the volume layout to improve performance'?

To improve performance, increase the stripe unit sizc. To achieveat leastan S'Y..break-up value, selecta stripe unit sizeby calculating 32K x (100/8)rounded to the nearcst power of two (5I2K):vxassist -g testdg relayout test stripeunit=512k


Cop)'flyhi ie 2006 Symautec Corporauon All rrghts reserved

Scenario 4

Suppose that you have a disk group named testdg that contains four disks. Youhave a IOO-MB volume. named test. striped across three disks with a stripe unitsize of 256K.

When you start a trace on the volume. run a performance test on the volume. andthen stop the trace on the volume. the following vxtrace output is displayed:


ICtrl+qvxtrace -g testdg -f /tmp/appiolab4.out -0 dev,disk I pg

8972 START read vdev test block 0 len 64 concurrency 1 pid 77518973 START read disk c1t8dOs2 op 8972 block 0 len 648973 END read disk c1t8dOs2 op 8972 block 0 len 64 time 28972 END read vdev test op 8972 block 0 len 64 time 28974 START read vdev test block 64 len 64 concurrency 1 pid 77518975 START read disk c1t8dOs2 op 8974 block 64 len 648975 END read disk c1t8dOs2 op 8974 block 64 len 64 time 08974 END read vdev test op 8974 block 64 len 64 time 08976 START read vdev test block 128 len 64 concurrency 1 pid 77518977 START read disk c1t8dOs2 op 8976 block 128 len 648977 END read disk c1t8dOs2 op 8976 block 128 len 64 time 08976 END read vdev test op 8976 block 128 len 64 time 0

Analyze the application I/O profile based on the vxtrace output. Analyze thenumber of concurrent processes, the application 110 size for each process. andwhether the process IS performing random or sequential I/O. What do younotice')

There is a single processperforming sequential reads of size32K on thevolume.

2 What changes might you make to the volume layout to improve performance"?

To improve performance, you must ensure that the single processcan usethe full handwidth provided hy the striped volume (that is. the 110sizeshould be equal to the full stripe width). To change the volume layout:vxassist -g testdg relayout test ncol=2 stripeunit=16kORvxassist -g testdg relayout test ncol=4 stripeunit=8k

Lab 6 Solutions: Performance Monitoring 8-87Capynghl 'f;' 20fl6 Symantec Corporanon. All nghl"; reserved

Optional Labs: Measuring Volume 1/0 Operations

In the following exercises, you determine whether reads or writes occur whenVxVM performs various actions.

Note: The solutions provided in this section show sample vxstat outputs from aSolaris platform. You may obscrv c different sizes if you arc working on an HP-UXplatform. This is because on HP-UX one sector is 1024 bytes, whereas on Solaris,one sector is 51 ~ bytes.

Optional Lab: When Creating a Disk Group

Docs VxVM write into the public region ola disk when it creates a disk group'.'

1 Create a disk group nameddatadg using six disks.vxdisksetup -i device_tag (if necessary)vxdg init datadg datadgOO=device_tagl \

datadgOl=device_tag2 datadg02=device_tag3 \datadg03=device_tag4 datadg04=device_tagS \datadg05=device_tag6

2 Determine whether Vx VM writes into the public region of a disk when itcreates a disk group.

vxstat -g datadg -fs -vpsd

rv> NAMEdm da tadgOOdm da tadgOldm datadg02dm datadg03dm datadg04dm datadg05

OPERATIONSREAD WRITE

o 0o 0o 0o 0o 0o 0

Bl.OCKSREAD WRITE

o 0o 0o 0o 0o 0o 0

AVG TIME (ms )READ WRITE

0.0 0.00.0 0.00.0 0.00.0 0.00.0 0.00.0 0.0

No, VxVM does not write into the public region of a disk when it creates adisk group.

Optional Lab: When Creating a Volume

Docs VxVM write into the volume, plcxcs. subdisks, or disks space when it createsa volume?

Rcset the read/write counters for datadg. Create a 50-MB, concatenated(RAID-O) volume nameddatavoll in datadg.

Did reads or writes to the volume, plcx, subdisk. or disk occur')vxstat -g datadg -r


Copynqht ;;·2006 Syrnantec Corporanon All r.qnts reserved


OPERATIONS BLOCKS AVG TlME(ms)TYP NAME READ WRITE READ WRITE READ WRITEdm datadgOO 0 0 0 0 0.0 0.0dm datadgOl 0 0 0 0 0.0 0.0dm datadg02 0 0 0 0 0.0 0.0dm datadg03 0 0 0 0 0.0 0.0dm da tadg04 0 0 0 0 0.0 0.0dm datadgOS 0 0 0 0 0.0 0.0

vxassist -g datadg make datavoll Samvxstat -g datadg -fs -vpsd datavoll

OPERATIONS BLOCKS AVG TIME(ms)TYP NAME READ WRITE READ WRITE READ WRITEdm datadgOO 0 0 0 0 0.0 0.0vol datavoll 0 0 0 0 0.0 0.0pl datavoll-Ol 0 0 0 0 0.0 0.0sd datadgOO-OI 0 0 0 0 0.0 0.0

1\0, VxVI\1 does not write into the volume, plexes,suhdisks, or disks spacewhen it creates a volume.

2 Reset the read/write counters for datadg. Create a30-M13, 3-column. striped(RAID-O) volume named datavo12 in datadg.

Did reads or writes occur"vxstat -g datadg -rvxassist -g datadg make datavol2 30m layout=stripe \neol=3vxstat -g datadg -fs -vpsd datavol2

OPERATIONS BLOCKS AVG TIME(ms)TYP NAME READ WRITE READ WRITE READ WRITEdm datadgOI 0 0 0 0 0.0 0.0dm datadg02 0 0 0 0 0.0 0.0dm datadg03 0 0 0 0 0.0 0.0vol datavo12 0 0 0 0 0.0 0.0pl da tavo 12-01 0 0 0 0 0.0 0.0sd da tadgOl-Ol 0 0 0 0 0.0 0.0sd datadg02-01 0 0 0 0 0.0 0.0sd datadg03-01 0 0 0 0 0.0 0.0

No, reads or writes did not occur.

3 Reset the read/write counters for datadg. Create a 30-MB. 2-way, mirrored(RAID-I) volume named datavo13 in datadg.

Did reads or writes occur'.' Did any synchronization occur')vxstat -g datadg -rvxassist -g datadg make datavol3 30m layout=mirror \nmirror=2vxstat -g datadg -fs -vpsd datavo13

TYP NAMEdm datadg04dm datadgOSvol datavo13p l datavol3-01sd datadg04-01p l datavo13-02sd datadgOS-OI


240 0o 240

30 030 030 0o 30o 30

BLOCKSREAD WRITE

61440 0o 61440

61440 061440 061440 0

o 61440o 61440

AVG TTME(ms)READ WRITE22.0 0.0

0.0 20.866.0 0.033.7 0.033.7 0.0

0.0 27.30.0 27.3

Lab 6 Solutions: Performance Monitoring 8-89

CopyrIght (C: 20(J() Symanter- Corcorauon All fights reServed

Yes, reads and writes did occur and synchronization betweenthe mirrorsdid occur.

4 What type or synchronization occurred between the mirrors')

vxstat -g datadg -fab -vpsd datavo13

TYP NAMEdm datadg04dm datadgOSvol datavo13pl datavoll-Olsd datadg04-01p l datavo13-02sd datadgOS-Ol

ATOMIC COPIESOPS BLOCKS AVG(ms)

o 0 0.0o 0 0.0o 0 0.0o 0 0.0o 0 0.0o 0 0.0o 0 0.0

READ WRITEBACKOPS BLOCKS AVG ems)

o 0 0.0o 0 0.0

30 61440 66.0o 0 0.0o 0 0.0o 0 0.0o 0 0.0

Read-write back synchronization occurred between the mirrors.

5 Reset the read/write counters tor datadg. Create a IOO-MH.3 column,striped, mirrored and logged volume (RAID 0+1) named datavo14 indatadg.

Did reads or writes OCCur"

vxstat -g datadg -rvxassist -g datadg make datavo14 100m \layout=stripe,mirror, log ncol=3vxstat -g datadg -fs -fb -vpsd datavo14

OPERATIONS BLOCKS AVG TIME(ms) REAQ-wRTTEBA(KTYP NAME READ WRITE READ WRITE READ wRITE DPS BLOCKS AVG(ms)dm datadgOO 5n 2 68224 32 8.6 0.0 0 0 0.0dm datadgO 1 0 534 0 68352 0.0 18.7 0 0 0.0dm datadg02 0 5n 0 68224 0.0 18.6 0 0 0.0dm datadg03 0 5n 0 68224 0.0 18.7 0 0 0.0dm datadg04 534 0 68352 0 7.6 0.0 0 0 0.0dm datadg05 533 0 68224 0 7.5 0.0 0 0 0.0vo l datavo14 100 0 204800 0 47.1 0.0 lUO 204800 47.1pl datavo14-01 0 100 0 204800 0.0 24.8 0 0 0.0sd datadgOl-02 0 534 0 68352 0.0 18.7 0 0 0.0sd datadg02-02 0 511 0 68224 0.0 18.6 0 0 0.0sd datadg03-02 0 531 0 68224 0.0 18.7 0 0 0.0pi dar avol a-D? 100 0 204800 0 16.6 0.0 0 0 0.0sd ddtadgOO-02 5n 0 68224 0 8.6 0.0 0 0 0.0sd datadg04· 02 534 0 68352 0 7.6 0.0 0 0 0.0so datadgOS-02 511 0 68224 0 7.5 0.0 0 0 0.0pl datavo14-03 0 0 0 0 0.0 0.0 0 0 o 0sd datadgOO-03 0 2 0 32 0.0 0.0 0 0 0.0

Yes, reads and writes occur between the mirrors and extra writes to thedisk with a log.

6 Why do writes occur when creating mirrors but not when creatingconcatenated or striped volumes')

:\otirrors must be synchronized to each other in RAID-\.

7 Reset the read/write counters lor da tadg. Create a 30-MI3.2-way mirrored, 3column striped and logged (RAID-I+O) volume named datavo16 illdatadg.


Copvnpnt ~i2006 Symantec Corpor auou All rights reserved

Did reads or writes occur'!

vxstat -g datadg -rvxassist -g datadg make datavol6 30m \layout=stripe-mirror,log nmirror=2 neol=3vxstat -g datadg -fs -vpsd datavol6

OPERATIONS BLOCKS AVG TIMf(ms)TYP NAME READ WRITE READ WRITE READ WRITEvo l datavo16 0 0 0 0 0.0 0.0pl datavo 16-04 0 0 0 0 0.0 0.0sd datavo16-S01 0 0 0 0 0.0 0.0sd datavo16-S02 0 0 0 0 0.0 0.0sd datavo16-S03 0 0 0 0 0.0 0.0

Note: When a layered (stripe-mirror or RAID-I +0) volume is involved, omitthe name of the high-level volume to get the statistics.


OPERATIONS BLOCKS AVG TlME(ms)TYP NAME READ WRITE READ WRITE READ WRITEdm datadgOO 80 0 20480 0 48.1 0.0dm datadq01 0 86 0 20576 0.0 35.6dm datadg02 0 80 0 20480 0.0 31.2dm datadg03 0 80 0 20480 0.0 36.1dm datadg04 80 0 20480 0 27.8 0.0dm datadg05 80 0 20480 0 29.6 0.0vol datavo16 0 0 0 0 0.0 0.0p l datavo16-04 0 0 0 0 0.0 0.0sd datavo16-S01 0 0 0 0 0.0 0.0sd datavo16-S02 0 0 0 0 0.0 0.0sd datavo16-S03 0 0 0 0 0.0 0.0vol datavo16-IOl 10 0 20480 0 98.0 0.0pl datavo16-POI 0 0 0 0 0.0 0.0sd datadgOl-05 0 2 0 32 0.0 0.0pI datavo 16- P02 0 10 0 20480 0.0 45.0sd datadgOl-06 0 ]0 0 20480 0.0 45.0pl datavol6-P03 10 0 20480 0 41.0 0.0sd datadg04-05 10 0 20480 0 41.0 0.0vol datavo16-L02 10 0 20480 0 98.0 0.0pl datavo 16-P04 0 0 0 0 0.0 0.0sd datadgOl-07 0 2 0 32 0.0 0.0pl datavo16-P05 0 10 0 20480 0.0 41. 0

sd datadg02-05 0 10 0 20480 0.0 41.0pl dat avo l Svr'Of 10 0 20480 0 45.0 0.0sd datadg05-05 10 0 20480 0 45.0 0.0vol datavo 16- L03 10 0 20480 0 ]59.0 0.0pl datavol6-p07 0 0 0 0 0.0 0.0sd datadgOl-08 0 2 0 32 0.0 0.0pi da t avo l fi-Pfl S 0 ]0 0 20480 0.0 44.0sd datadg03-05 0 ]0 0 20480 0.0 44.0pl dat.avo16-P09 ]0 0 20480 0 105.0 0.0sd datad 00-07 10 0 20480 0 105.0 0.0

8 Does VxVM write into the volume. plcxes. subdisks. or disks when it creates avolume?

Yes, when a mirrored volume is created.

9 Reset the read/write counters for datadg. Create a 5MB mirrored volumenamed datavol 7 and initialize it to zero. Is the volume's address spacewritten when it is initialized to zero'?

vxstat -g datadg -rvxassist -g datadg make datavol7 5m \layout=eoneat,mirror init=zero

Lab 6 Solutions: Performance Monitoring B-91Copynght'~ 2006 Symanler.Corporauon fill "gilts reserved

vxstat -g datadg -fs -vpsd datavo17

TYP NAMEdm datadgOOdm datadg02vol datavo17p l datavo17-01sd datadgOO-O\pi datavo17-02sd da tadg02 -04


o 42o 42o 42o 42o 42o 42o 42

BLOCKSREAD

ooooooo

WRITE10240102401024010240102401024010240

AVG TIME(ms)READ WRITE

0.0 8.80.0 11.00.0 17.10.0 8.80.0 8.80.0 11.00.0 11.0

Yes, the volume's address spaceis written when it is initialized to zero.

Optional Lab: When Mirroring a Volume or Resynchronizing Mirrors

Docs VxVM write into the volume, plcxcs, subdisks, or disks when it mirrors avolume or rcsynchronizcs mirrors'?

Create a 50-MH. concatenated (RAID-I)) volume named datavo18 indatadg.

vxassist -g datadg make datavo18 SOm

2 Reset the read/write counters for datadg. Add a mirror to the datavo18volume,

Did reads and/or writes occur" DO':5 adding a mirror perform atomic-copy orrcud-writcback?

vxstat -g datadg -rvxassist -g datadg mirror datavo18vxstat -g datadg -fs -vpsd datavo18

OPERATIONS BLOCKS AVG TIME(ms)TYP NAME READ WRITE READ WRITE READ WRITEdm datadgOO 413 0 102400 0 3.6 0.0dm datadg02 0 413 0 102400 0.0 6.2vol datavo18 0 0 0 0 0.0 0.0pI datavo 18-01 413 0 102400 0 3.6 0.0sd datadgOO-06 413 0 102400 0 3.6 0.0pI datavo 18-02 0 413 0 102400 0.0 6.2sd datadg02-06 0 413 0 102400 0.0 6.2

vxstat -g datadg -fab -vpsd datavo18

ATOMIC COPIES READ-WRITE BACKTYP NAME OPS BLOCKS AVG(ms) OPS BLOCKS AVG(ms)dm datadgOO 0 0 0.0 0 0 0.0dm datadg02 0 0 0.0 0 0 0.0vol datavo18 413 102400 9.8 0 0 0.0pI datavo18-01 0 0 0.0 0 0 0.0sd da tadgOO - 06 0 0 0.0 0 0 0.0pI datavo18-02 0 0 0.0 0 0 0.0sd datadg02-06 0 0 0.0 0 0 0.0

Ycs, reads and 'Hites occur. Atomic-copy is performed.

3 What is the meaning of atomic copy'!

Atomic-copy resynchrnnizarton refers to the sequential writing of allblocks of the volume to a plex,

8-92 Education and SRT FrameMaker Template SetCcpvnunr ~ 20()6 Symamec Corporano- 1\11nqhts reserved

Optional Lab: When an Application Performs 110to a Volume

Create a SOO-MS.concatenated (RAID-O) volume named datavo19 indatadg.vxassist -g datadg make datavol9 500m

2 Reset the read/write counters for datadg. Start 1/0 to the dat avo19 volumeusing dd in the background. While the 1/0 is ongoing examine reads or writes.Kill the dd process when you arc finished.vxstat -g datadg -rdd if=/dev/zero of=/dev/vx/rdsk/datadg/datavol9 \bs=1024 &

vxstat -g datadg -i2 -vpsd datavol9

OPERATIONS BLOCKS AVG TIME(ms)TYP NAME READ WRITE READ WRITE READ WRITE

rhu 11 sep 2003 05; 39; 55 PM EDTdm datadg03 0 420 840 0.0 .9vol datavo 19 0 420 840 0.0 .9pi datavo 19-01 0 420 840 0.0 .9sd datadg03 -04 0 420 840 0.0 .9

rhu 11 sep 2003 05. 39; 57 PM EDTdm datadg03 0 271 0 542 0.0 .9vol datavo19 0 271 0 542 0.0 .9pi datavo19-01 0 271 0 542 0.0 .9sd datadg03-04 0 271 0 542 0.0 .9

Thu 11 Sep 2003 05; 39; 59 PM EDTdm datadg03 0 308 616 0.0 .9vol datavol9 0 308 616 0.0 .9pi datavo19-01 0 308 616 0.0 5.9sd datadg03-04 a 308 616 0.0 5.9

Use CNTL+C to cancel the vxstat command. If the dd process is stillrunning, kill the dd process:

ps -ef I grep ddkill -9 process-id

3 Assuming that there is only one process doing I/O to the disk (no parallel 1/0)and that there are 512 bytes per block. how would you calculate the I/Othroughput to the disk')No. of Blocks x S12/( No. of 1/0 Operations x Average I/O Time/ I0(0) BlsecDivide by 1024 for KB/seeDivide by 1024 for MB/scc

4 Illustrate that one 1'0 to the mirrored volume datavo18 generates two I/Oswithin the volume.vxstat -g datadg -r

Lab 6 Solutions: Performance Monitoring B-93Copynqtu Cr,'2001:> Symanter. coroorauo- All nqtits reservec

dd if=/dev/zero of=/dev/vx/rdsk/datadg/datavol8 \bs=1024 &

vxstat -g datadg -i2 -vpsd datavol8

OPERATIONS BLOCKS AVG TIME(mS)TYP NAME READ WRITE READ WRITE READ WRITE

lhu 11 sep 2003 06:02 : 36 PM EDTdm da tadgOO 0 15967 0 31934 0.0 4dm datadg02 0 15967 0 31934 0.0 6vol datavolB 0 15967 0 31934 0.0 9pl da tavo 18-01 0 15967 0 31934 0.0 4sd datadgOO-06 0 15967 0 31934 0.0 41'1 datavolS-02 0 15967 0 31934 0.0 6sd d. tadg02-06 0 15967 0 31934 0.0 6

Thu 11 sep 2003 06 02: 38 PM EDTdm datadgOO 0 324 0 648 0 5 .7dm datadg02 0 324 0 648 0.0 3 6vol datavo18 0 324 0 648 0.0 5 .9pl datavo18-01 0 324 0 648 0.0 5. 7sd datadgOO-06 0 324 0 648 0.0 5. 71'1 datavo18-02 0 324 0 648 0.0 3 6sd datadg02-06 0 324 0 648 0.0 3 6

The numbers are cumulative since the reset. In the example, 324 volumelevel writes generated an equal number to each of two plexes.

Use C:'IITL+C to cancel the vxstat command. If the dd process is stillrunning, kill the dd process:

ps -ef I grep ddkill -9 process-id

Optional Lab: When Removing a Volume

Does V.xVM write into the volume, plcxcs, subdisks. or disks when it removes avolume'!

Reset the read/write counters for datadg. List the volumes in datadg.vxstat -g datadg -rvxprint -g datadg -v

TY NAME ASSOC K5TATE LENGTH PLOFFS STATE TUTILO PUTILOv datavoll fsgen ENABLED 102400 ACTIVEv datavo12 fsgen ENABLED 61440 ACTIVE

datavo13 fsgen ENABLED 61440 ACTIVEdatavo14 fsgen ENABl ED 204800 ACTIVE

v datavo16 fsgen ENABLED 61440 ACTIVEv dalavo16-L01 fsgen ENABLED 20480 ACTIVEv datavol6-L02 fsgen ENABLED 20480 ACTIVEv datavo 16-L03 fsgen ENABl ED 20480 ACTIVEv datavo17 fsgen ENABLED 10240 ACTIVEv datavo18 fsgen ENABL ED 102400 ACT rVE

s: datavol9 fsgen ENABl ED 1024000 ACTIVE

2 Remove the datavoll volume.

vxassist -g datadg remove volume datavoll


3 Does YxYM write into the volume, plcxcs. subdisks, or disks when it removesa volume') What does this imply'?vxstat -g datadg -fs -vpsdNo, VxVM duesnut write intu the volume, plexes,subdisks, ur disks whenit removes a volume. This implies that a volume whose definition getscorrupted ur is accidentally deleted can be restructured.

Optional Lab: When Removing a Plex

Does Yx YM write into the volume, plcxcs, suhdisks. or disks, when it removes aplcx?1 Reset the read/write counters for datadg. List the volumes in datadg.

vxstat -g datadg -rvxprint -rhtg datadg

v datavo18pi datavo18-01 datavo18sd datadgOO-06 da tavo18-01pl datavo18-02 datavo18sd datadg02-06 datavo18-02

ENABLED ACTIVEENABLED ACTIVEdatadgOO 262143ENABLED ACTIVEdatadg02 283689

102~00104139104139104139104139

SELECTCON CAToCON (ATo

cltOdO

clt2dO

fsgenRWENARWENA

2 Does YxYM write into the volume, plexes, subdisks, or disks when it removesa plex? What does this imply"vxassist -g datadg remove mirror datavolBvxstat -g datadg -fa -vpsd datavolB

OPERATIONS BLOCKS AVG fIME(ms)TYP NAME READ WRITE READ WRITE READ WRITEdm da tad gOO 0 0 0 0 0.0 0.0vol datavo18 0 0 0 0 0,0 o 0pl datavo18-01 0 0 0 0 0.0 0,0sd datadgOO-06 0 0 0 0 0.0 0.0

No, VxVM dues nut write into the volume, plexes,subdisks, ur disks whenit removes a plex. This implies that a plex whose delinitiun gets corruptedor is accidentally deleted can be restructured.

Optional Lab: When Destroying a Disk Group

Does YxYM write when it destroys a disk group'?1 Reset the read/write counters for datadg. Destroy datadg. Did any writes

occur')vxstat -g datadg -r

Lab 6 Solutions: Performance Monitoring 8-95Copyright i:"' 2006 Symanter Corporauo» All nqtus reserved

vxstat -g datadg -fs -vpsdvxdg destroy datadgIt is impossible to ascertain in VxV:\'I if any writes occur.

2 Docs VxVM write into the public urea "I' the disk when any of the aboveoperations arc performed What docs this imply for administration ofvolumes

Only the private region of a disk is updated when volumes are created anddestroy ed, mirrors added and removed, etc.

This implies that with a current backup of the configuration database, adisk group and volume can be reconstructed.


Copyright "t! 2Dll6 Symantec Corporation All fights reserved

symantec



Lab 7 Solutions: Point-in-Time CopiesIn this lab, you perform off-host processing using third-mirror break-off volumesnapshots, create space-optimized instant volume snapshots, and restore a tilesystem using storage checkpoints. Optionally, you also create and investigate full-sized instant volume snapshots.


Prerequisite Setup

To perform this lab, you need a lab system with Storage Foundation pre-installed,configured and licensed. In addition to this, you also need at least four disks to beused in a disk group.

Before starting this lab you should have all the external disks assigned to youalready initialized but free to be used in a disk group.

Lab 7 Solutions: Point-in-Time Copies

Copyngt11 © 2()06 Symantec Corporation All fights reser"",d

8-97


In preparation for this lab. you will need the following information about your labenvironment. For your reference. you may record the information here, or referback to the first lab in the SF Fundamentals section where you initiallydocumented this information.


Host name trainl

Host name of the system train2sharing disks n ith mysystem~Iy Data J)jsks: Solaris: clt#dO -

clt#d5HP-LX: c4tOdO -c4tOd5/\IX: hdisk21-hdisk26Linux: sda - sdf


Copvnqht s 2006 Sj'nldntec corroranou All fights resHrved

Off-Host Processing Using Third Mirror Break-off Volume Snapshots

Phase I: Create, Split, and Deport

1 Identity the name of the system that is sharing access to the same disks as yoursystem. If you are not sure. check with your instructor. Note the name ofthepartner system here.

Partner system hostnarnc:

2 011your local lab system. create a disk group called namedg with four disks.

VEA

a Select Disk Groups node in the object tree and select Actlons=-c-NewDisk Group.

b In the New Disk Group wizard, click "ext to skip the Welcome page.

e Type the name of the disk group. Ensure that Enable Cross-platformData Sharing (CDS) remains checked.

d Select the disks you want to add to the disk group and click Add tomove them to the Selected disks area. Click Next to continue.

e Confirm the disk selection.

Do not select a disk group organization principle when prompted.

9 Click Finish.

CLI

vxdisksetup -i device_tag (lf ncccssary)vxdg init namedg namedgOl=device_tagl

namedg02=device_tag2 namedg03=device_tag3namedg04=device_tag4

3 Create a 500-MB concatenated volume. namevoll. using a single disk.Create a Veritas file system on the volume and mount the file system on themount point / namel.

VEA

a llighlight the disk ~rollp and select Actions-c-o-New Volume.

b Let VxVM select the disks to use.

e Specify the volume name, the size, a concatenated layout, and nomirror.

d Add a file system and set the mount point. Uncheck the Add to liIesystem table option.

CLl

Lab 7 Solutions: Point-in- Time Copies 8-99COPYright';;::2006 Svmantec Corporation All fights reserveo

vxassist -g namedg make namevoll SOOmmkfs -F vxfs /dev/vx/rdsk/namedg/namevoll

Note: On Linux, usemkfs - t.

mkdir / namel (i fit doesn't already exist)

mount -F vxfs /dev/vx/dsk/namedg/namevoll /namelNote: On Linux, usemoun t - t.

4 Add data to the Ilk system using the following command:

echo "Pre-snapshot for name" > /namel/presnap on nameand veri Iy that the data has been added.

1s /name1

5 Lnablc Fasikcsync for the volume namevoll. Can you identify what haschanged'!

VEA

a Highlight the namevoll volume. In the Actions menu, select InstantSnapshot->Enable FastResync.

b In the Enable Fasrkesync window, accept all the defaults and clickOK.

e Select the namevo11 volume in the ohject tree. Note the OCO tab inthe right pane view. Select the OCO tab and observe the log added tothe volume.

CLl

vxsnap -g namedg prepare namevollvxprint -g namedg -htr

A OCO log has beenaddcd to the volume.

6 Add a mirror to the volume for use as the snapshot. Observe the volume layout.What is the state of the newly added mirror alter synchronization completes?

YEA

a Select the volume then Actions ->Instant Snapshot=c-AddSnapshotMirror.

b Let \'xV\'! select the disks to use.e Select the volume in the object tree and click the Mirrors tab in the

right pane. Note that the type of the newly added mirror is displayedas Snapshot and the status changesfrom Snap In Progress to SnapReady when the synchronization curnpletes.

CLl


Cr;pyngh!~, 2006 Svrnamec Corporation All nqnts reserved

vxsnap -g namedg addrnir namevollvxprint -g namedg -htrThe status of the newly added mirror should change from E~ABLEDIS'IAPATT to E'iABLED/S,\APDO'lE after the synchronization iscomplete.

7 Create a third mirror break-otfsnapshor named namesnap 1 using the newmirror you just added. Use the vxsnap -g namedg 1is t command toobserve the snapshots in the disk group. Can you find similar information illthe VEA GUt"

YEA

a Highlight the volume and select Actions->Instant Snapshot->Create.

b In the Snapshot Type dialog box, select Break off.c Verify one mirror to break off.d Confirm that you want to usea mirror.e Specify the snapshot name.In the object tree the snapshot volumes are displayed under their parentvolume. If you select the Volumes node in the object tree, you will noticethat the icons for the snapshot volumes are different from standardvolumes. The Properties view for a snaphost volume lists the parentvolume name.

eLl

vxsnap -g namedg make \source=namevoll/newvol=namesnapl/nmirrors=l

vxsnap -g namedg listThe namesnapl volume is listed as a break-off snapshot of namevoll.

8 Split the snapshot \'ohIl1IC into a separate disk group from the original diskgroup called nameOHPdg:

YEA

Nnte: Although the solution for VEA has been provided here, on theSolaris platform you may needto perform this step from the commandline becauseof a GUI bug with 5.0 software on this platform.a Ilighlight the disk group and select Actions->Split Disk Group.b Type the new disk group name.

8-101Lab 7 Solutions: Point-in-Time Copies

Copvoqru 1" 2006 Symaruec Corpcr auou. All fights reserved

c Select tu split disk group by volumes and move namesnapl to theselectedvolumes area. Click OK.

CLl

vxdg split namedg nameOHPdg namesnapl

9 Verify that the nameOHPdg disk group exists and contains namesnapl.First, display the disk groups on the system. You should see the newnameOHPdg disk group displayed. Then, view the volume information for thenameOHPdg disk group.

VEA

a Select the Disk Groups node in the object tree. The nameOHPdgshould be listed as imported.

b Highlight the nameOHPdg disk group in the object tree and selecttheVolumes tab in the right pane to observe the volumes in the disk group.

CLl

vxdg list

vxprint -g nameOHPdg -htr

10 Deport the disk group that contains the snapshot volume. If you have a partnersystem that sharesaccessto the external disks with your system, you can usethe new host information using the hostname ofthe partner system.

VEA

Highlight the disk group and selectActions->Deport Disk Group. (Donot select Deport Options unlessyou have a partner system).Click OKand couflrm when prompted.

CLl

vxdg deport nameOHPdg

11 View the disk groups on the system.

VEA

Select the Disk Groups node in the object tree. The nameOHPdg diskgroup is now listed as deported.

CLI

vxdg list

8--102 VERITAS Storage Foundation 5.0 for UNIX: Maintenance

Copvnqnt '~' 20(1) Symantec Corroranon AIIII(JnlS reserve-t

The nameOHPdgdisk group is not displayed because it is deported.

Run the vxdisk command to view the status of the disks on the system.Alternatively. you can view the status of the disks in VEA.

VEA

Select the Disks node in the object tree. The disk used for namesnap1 islisted as Deported.

CLI

vxdisk -0 a11dgs listThis shows that the disk used for namesnap1 is deported. (nameOHPdg)in parentheses shows that the nameOHPdgdisk group is deported.

12 Add additional data to the original volume using the following command:

echo "Post-snapshot for name" > \/namel/postsnap_on_name


15 /name1

Phase 2: Import, Process, and Deport

13 Remote login to the partner system which will be used as the off-hostprocessing (OIIP) system.

Notes:

If you arc working on a standalone system. skip this step and use your ownsystem as the partner system.

If you want to continue using the graphical user interface (VEA) on thepartner system, you need to connect to the partner system using the VEAclient on your local system.

rlogin partner_system_hostname

14 On the off-host processing (OIIP) host (your partner system) where the backupor processing is to be performed, import the disk group that contains thesnapshot volume.

Note: You may need to rcscan the disks using the vxdct 1 enablecommand on the OIIP host so that the host detects the changes.

VEA

On the OHP host highlight the nameOHPdgdisk group and selectActiuns=-c-Import Disk Group.

CLI

Lab 7 Solutions: Point-in-Time Copies 8-103Coovnqnt ~ 2006 Syrnantec Corocrauoo Atl notus reserven

vxdg import nameOHPdg

View tile status olthc volume in tile nameOHPdg disk group.

VEA

Highlight the nameOHPdg disk group in the object tree and selecttheVolumes tab in the right pane.

CLI

vxprint -g nameOHPdg -htr

15 To perform off-host processing. you must first start tile volume and mount tileIiI.: system on tile off-host processing host. Use the mount point/ namesnapl.

YEA

The volume is automatically started if you had used the default Start allvolumes option while importing the disk group.Highlight the volume and selectActions->File System->Mount FileSystem.Do not add the tile systemto the tile systemtable.

CLI

vxrecover -g nameOHPdg -s namesnaplvxprint -g nameOHPdg -htr

mkdir /namesnapl (if the directory docs not already exist)mount -F vxfs /dev/vx/dsk/nameOHPdg/namesnapl \

/namesnaplNote: On Linux, usemoun t - t.

16 View and compare the contents 01' both file systems.

On the local lab system:Is -1 /namelOn the partner (OHP) system:Is -1 /namesnapl

There is one more tile in / namel than in / namesnapl. The file that hasbeen written after the snapshot operation (pos tsnap _ on_name)existsin / namel but not in / namesnapl. The file that has been wrjtten beforethe snapshot operation (presnap_on_name) exists in both tile systems.

17 Check if you can write to the snapshot file system during off-host processingby creating a new file in the snuphsot file system as follows:


COPY"\lr,("- 2006 SyruantecCorporaucn All nqnts reserved

echo "Oata in snapshot of name" > \

/namesnapl/data_on_namesnaplIs -1 /namesnapl

18 After completing off-host processing. you are ready to reattach the snapshotvolume with the original volume. Unmount the snapshot volume on the off-host processing host.

CLI

YEA

Highlight the volume and select Actions->File System->Unmount FileSystem. Confirm when prompted.

umount /namesnapl

Note: If you have been using your local lab system as the OIIP host. you do notneed to perform the next three steps ( 19-21). Ilowever. in an actual off-hostprocessing situation. you would perform these steps.

19 On the OIIP host, deport the disk group that contains the snapshot volume.

YEA

a Highlight the disk group and select Actions->Deport Disk Group.

b Click OK (Do not select Deport Options unless you are working" ith apartner's system).

c Confirm that you want to deport the disk group.

CLI

vxdg deport nameOHPdg

20 If you had been working on a partner system. exit from the partner system.Alternatively. if you had been using the VEA. disconnect from the partnersystem.

YEA

a Select File-->Disconnect.

b Select the partner system and click OK.

CLI

On the OHP host:exit

Lab 7 Solutions: Point-in-Time Copies B-105Copyrlghl <f; 20U6 Svroa-uec Corcorsuoo All rlghls reserverl

Phase3: Import, Join, and Resynchronize21 011 the primary host (your local lab system), rcimport the disk group that

contains the snapshot volume:

VEA

a Highlight the disk group and selectActions->Import Disk Group.b Verify that the Start all volumes option is selected.Click OK.

CLI

vxdg import nameOHPdgvxdg list

22 Rejoin the disk group that contains the snapshot volume to the disk group thatcontains the original volume.

VEA

a Highlight the disk group and selectActions->Join Disk Group.b Ensure that the source disk group is nameOHPdg and the target disk

group is namedg. Click OK.Note: If )'OU get an Object not found error in VEA, ignore it. Thiserror is displayed becausethe nameOHPdg no longer exists on thesystem.

CLI

vxdg join nameOHPdg namedgvxprint -g namedg -htr

23 At this point you should have the original volume and its snapshot in the samedisk group but as separatevolumes. There is still 110 synchronization betweenthe original volume and the snapshot volume. To observe this. the snapshotvolume will be mounted again to observe its contents. You would not need toperform this step during a normal off-host processing procedure. Note that ifyou have been using the CLI. the snapshot volume is initially disabledfollowing the join.a Restart the snapshot volume if necessary.

VEA

Select the snapshot volume, and select Actions->Rccover Volume.

eLl

vxrecover -g namedg -s namesnapl


Ccpynqntc 2006 Swnantec corooranon 11.11rights reserved

vxprint -g namedg -htrMake sure the snapshot volume is E'ABLED and ACTIVE.

b I f necessary, run a f le system check on the snapshot volume. Note that thisstep should not be necessary if you haw cleanly unmounted the file systembefore the deport on the 0111' host.

VEA

Select the snapshot volume, and selectActions->File System->Check File System.Xote: The Check File System option may be grayed out in VEA if thefile system does not need a check.

CLI

Snlarls, fsck -F vxfs /dev/vx/rdsk/namedg/namesnap1liP-LX

l.inux fsck -t vxfs /dev/vx/dsk/namedg/namesnap1

c Mount namesnapl back on the /namesnaplmollnt point. Create themount point if necessary.

VEA

Select the snapshot volume, and selectActions->File System=c-Muunt File System. Ensure that the filesystem is not added to the file system table.

CLI

mkdir /namesnap1 (if the directory does not already exist)mount -F vxfs /dev/vx/dsk/namedg/namesnap1 \

/namesnap1'ote: On Linux, usemount - t.

d View and compare the contents of both Ii Ie systems.

ls -1 /name1 /namesnap1

e Unmounr the /namesnapl file system.

VEA

Select the snapshot volume, and selectActions->fih.' System->Unmount file System. Confirm when


Copyright», 2006 Syuianter-Corporation All nqtusre~erved

prompted.

eLl

umount /namesnapl

24 On the:primary host (your local lab system), reattach tile plcxcs ofthe snapshotvolume to the original volume and rcsynchronizc their contents.

VEA

a Select the snapshot volume, and select Actions->Instant Snapshot->Reattach.

b Verify that Volume to attach to is set to namevoll.c Click OK.

eLl

vxsnap -g namedg reattach namesnapl source=namevoll25 Remove the snapshot mirror.

YEA

a Select the namevoll \'01111111.', and select Actions->InstantSnapshot-> Remove Snapshot Mirror.

b Accept the Automatic mirror selection option and click OK.

eLl

vxsnap -g namedg rmmir namevoll

Using Space-Optimized Instant Volume Snapshots

Select a disk in the namedg disk group that is not used by the original volumenamevoll. and create a 50-MB volume on this disk to be used as the cachevolume. Name the:cache volume namecachevol. Create a cache objectcalled namecache on the cache volume. Ensure that the cache object isstarted.

Note: If you use the VEA to create the cache:object. the autogrow optionwill be kit at the default value ofo t f . ltyou usc the command line you canchange: this setting to on while: creating the cache object.

YEA


C:ODyngh! I 2U06 Svmautec Corporation All flghls reserved

Select the namedg disk group in the object tree and select the Disk Viewtab to observe the disk usagein the disk group. Identity a disk that is notused by any other VxVM object in the disk group. To create the volume:a Uighlight the namedg disk group. Select Acnons=c-New Volume.b Manually select disks to use for this volume. Click Next.c Selectan unused disk, for example namedg04, and add it to the

Included section using the > key. Click Next.d Specify the volume name, the size,a concatenated layout, and no

mirror. Click :\ext.e Select the Create as a Snapshot Cache Volume option. Enter the cache

object name as namecache. Leave the Region Size as 0 to use thedefault value. Click "Iext.

f Do not add a lile system when prompted.9 Click Finish to complete the wizard.

eLl

vxprint -g namedg -htrvxassist -g namedg make namecachevol SOmnamedg##where namedg## is the disk media name of the disk that is unused in thenamedg disk group.vxmake -g namedg cache namecache \

cachevolname=namecachevol autogrow=onvxcache -g namedg start namecache

2 Observe how the cache object and the cache volume is displayed in the diskgroup.

VEA

a Select the Volumes node in the object tree. Note the icon used for thecache volume.

b Right click the cache volume in the right pane and select Properties.c :\ote the cache object name displayed. Click Cancel.

eLl

vxprint -g namedg -htr

3 Verify that the namevoll volume is already prepared for instant snapshotoperations by displaying information about the DCO log.

VEA

a Select the namevoll volume in the object tree.

Lab 7 Solutions: Point-in-Time Copies 8-109Copyright (!;~2006 Symauter Corporation 11.11nqrus reserved

b Click the DCO tab in the right pane view.

I f you do not see a DCO tab, you need to prepare the volume forinstant snapshot b~' highlighting the volume and selectingAcuons=c-Insraut Snapshot->Enable FastResync.

CLl

vxprint -g namedg -htr namevol1\'ou should observe a DCO log.

4 Add data to the / name1 file system using the following command:

echo "New data before SOS1 for name" > \/name1/presos1 oD_name1

and veri Iy that the data is written.

Is -1 /namel

5 Create a space-optimized instant snapshot of the namevo11 volume. namednamesos 1. using the cache object namecache.

VEA

a Highlight the namevoll volume and select Actions->InstantSnapshot->Create.

b If necessary, click Next on the welcome page.

e Select Space optimized as the snapshot type. Click Next.

d Select Choose an existing cache object and verify that the name of thecache volume is selected in the Cache objects field. Click Next.

e Enter the name of the snapshot volume and click Next.Click Finish to complete the wizard.

CLI

vxsnap -g namedg make \source=namevoll/newvol=namesosl/cache=namecache

6 Display intormution about the snapshot volumes using the VEA. or thevxp r int , vxsnap list and vxsnap print commands from thecommand line.

VEA

a Select the Volumes node in the object tree. Observe the informationprovided lor the namesos1volume in the right pane. Note that the layoutis specified as Space Optimized,

8-110 VERITAS Storage Foundation 5.0 for UNIX: MaintenanceCupyrlght 0 200fi SyruautecCorporano» All fights fPserved

b Note the hierarchy of the objects displayed in the object tree under theVolumes node.

ell

vxprint -g namedg -htrvxsnap -g namedg printvxsnap -g namedg list

7 Using the command line. verify which snapshots are associated to the cacheobject.

vxcache -g namedg listvol namecache

8 Mount the space optimized snapshot volume namesosl to the /namesosldirectory.

VEA

Select the namesosl volume, and selectActions->File System->MountFile System, Enter the mount point and ensure that the file system is notadded to the file system table.

CLI

mkdir /namesosl (if necessary]mount -F vxfs /dev/vx/dsk/namedg/namesosl /namesosl

9 Observe the contents of the /namesosl directory and compare it to thecontents of the / namel directory.

Is -1 /namesosl /namelThe contents of both file systemsshnuld be exactly the sameat this point.

10 Add data to the /namel file system using the following command:

echo "New data before 8082 for name" > \

/namel/presos2 oD_nameland verify that the data is written.

1s -1 /namel

11 Create a second space-optimized instant snapshot of the namevoll volume,named namesos2. using the same cache object namecache.

VEA

a Highlight the namevo11 volume and select Actions->InstantSnapshot->Create.

Lab 7 Solutions: Point-in-Time Copies B-111

COP)'flCJh!~; 2006 Svrnaruec Comoranon All nqnts resevec

b If necessary, click :'Iiext on the welcome page.

c Select Space optimized as the snapshot type, Click Next.

d Select Choose an existing cache object and verify that the name of thecache volume is selected in the Cache objects field. Click Next.

e Enter the name of the snapshot volume and click Next.Click Finish to complete the wizard.

eLl

vxsnap -g namedg make \source=namevo11/newvo1=namesos2/cache=namecache

12 Using the command line. verify which snapshots arc associated to the cache!object.

vxcache -g namedg 1istvo1 namecache

13 Mount the space optimized snapshot volume namesos2 to the /namesos2directory,

VEA

Select the namesos2 volume, and select Actions->File System=c-MnuntFile System. Enter the mount point and ensure that the file system is notadded to the file system table.

CLI

mkdir /namesos2 (if necessary)mount -F vxfs /dev/vx/dsk/namedg/namesos2 /namesos2

14 Observe the contents of the original file system and the two space optimizedsnapshots,

ls -1 /namel /namesosl /namesos2

15 Make the following changes on the file systems:

a Remove the data you had on the original file system prior to starting theUsing Space-Optimized Instant Volume Snapshots section, If you havefollowed the lab steps. you need to remove the presnap _ on_name andpostsnap_on_name files lrom thc /namelliic system,

rm /namel/presnap on name

rm /namel/postsnap_on_name

b Add new data to the space optimized snapshot volumes using the followingcommands:

echo "New data on nameSOS1" > \/namesosl/data on_namesosl


CUI'ynghl i'- 201)6 Svo.antec Corpnrauon All nqbts reser.ed

echo "New data on nameSOS2" > \

/namesos2/data on namesos216 Observe the contents of the original tile system and the two space optimized

snapshots.

1s -1 /name1 /namesos1 /namesos2

17 Assume that you have decided to use the contents of the second spaceoptimized snapshot as the final version of the original file system. Restore theoriginal file system using the second space optimized snapshot. Note that youwill have to unmount the original file system to make this change. Mount theoriginal file system back to / namel directory when the restore operationcompletes.

VEA

a Highlight the namevo11 volume in the object tree and selectActions->File System=c-Unmounr Fill' System, Confirm whenprompted.

b Highlight the namevo11 volume in the object tree and selectActions->I nstant Snapshot->Restore.

c Verify that the Snapshot field is set to namesos2 and that theSynchronize option is checked. Click OK.

d Highlight the namevoll volume in the object tree and selectActions->File System->Mount File System. Enter the mount puintand ensure that the lile system is not added to the file system table.Click OK.

eLl

umount /name1vxsnap -g namedg restore namevo11 source=namesos2mount -F vxfs /dev/vx/dsk/namedg/namevo11 /name1

18 Observe the contents of the original tile system and the two space optimizedsnapshuts.ls -1 /name1 /namesos1 /namesos2:\ote that the contents of the second space optimized snapshot and theoriginal file system are now the same. whereas the contents of the firstspace optimized snapshot remain unchanged.

19 Refresh the first space optimized snapshot. namesosl. Note that you willneed to unmount the first space optimized snapshot to make this change.Mount the namesosl volume again after its contents are refreshed.

VEA


COPY'lql)1 -, 2{)06 Symanter Corrorauoo All rights reserved

a Selectthe Volumesnode in the object tree and highlight the namesoslvolume in the right pane. SelectActions->Filc System->UnmountFile System.Confirm when prompted.

b Uighlight thc namesosl volume in the right pane and selectActions->Instant Snapshot->Refresh. Click OK.

c Uighlight the namesosl volume in the right pane and selectActions->File System->.V!ount File System. Enter the mount point(/ namesosl) and ensure that the file system is not added to the filesystemtable. Click OK.

CLI

umount /namesoslvxsnap -g namedg refresh namesosl source=namevollmount -F vxfs /dev/vx/dsk/namedg/namesosl /namesosl

20 Observe the contents otthc original file system and the two space optimizedsnapshots.

Is -1 /namel /namesosl /namesos2Nnre that the contents should all be the samenow.

21 Unmount the two space optimized snapshots and dissociate them from theoriginal volume.

VEA

a Selectthe Volumesnode in the object tree and highlight the namesoslvolume in the right pane. SelectActions->File System->UnmountFile System.Confirm when prompted.

b Highlight the namesosl volume in the .-ight pane and selectActions->Instant Snapshot->[)issociate. Confirm when prompted.

c l/ighlight the namesos2 volume in the rightl)anc. SelectActions->File System->Unmount File System.Conlirm whenprompted.

d Highlight the namesos2 volume in the right pane and selectActions->Instant Snapshot->[)issociate. Confirm when prompted.

CLl

umount /namesoslumount /namesos2vxsnap -g namedg dis namesoslvxsnap -g namedg dis namesos2

22 Remove the space optimized snapshot volumes.


CUflyngill 2'106 Symilnt'!l- COfll',lfatollO Ali fI'-Jhtsreservec

'Iote: If you want to use the vxassist remove volume command todelete the volume from the command line, you first need to delete the DCOlog. Alternatively you can use the vxedi t -g diskgroup - rf rmvol woe_namecommand to remove the volume together with the associated0('0 log.

VEA

eLl

a Highlight the namesos1 volume in the right pane and selectActtons=c-Delete Volume. Conlirm when prompted.

b Highlight the namesos2 volume in the right pane and selectActions->Delete Volume. Confirm when prompted.

vxassist -g namedg remove log namesosl logtype=dcovxassist -g namedg remove volume namesos1vxassist -g namedg remove log namesos2 logtype=dco

vxassist -g namedg remove volume namesos2

Alternatively.vxedit -g namedg -rf rm namesos1vxedit -g namedg -rf rm namesos2

23 Remove the cache object with its associated cache volume.

VEA

mghlight the cache volume, namecachevo1, in the right pane and selectActions->Delete Volume. Confirm when prompted,

YEA

vxedit -g namedg -rf rm namecache

24 Unmount the / namel file system and remove the original volume,namevoll.'Iote: If you want to use the vxassist remove volume command todelete the volume from the command line. you first need to delete the DCOlog. Alternatively you can use the vxedi t -9 diskgroup - rf rmvol woe_namecommand to remove the volume together with the associatedDCO log.

YEA

a Highlight the namevoll volume in the right pane and selectActions->Unmount File System.Confirm when prompted.

Lab 7 Solutions: Point-in-Time Copies B-115Copyr.qht t~2006 Symantec Corporanon 1\11n9hl~ reserved

b Highlight the namevoll volume in the right pane and selectActions->Dclete Volume. Confirm when prompted.

eLl

vxassist -g namedg -f remove log namevoll logtype=dcovxassist -g namedg remove volume namevollAlternatively,vxedit -g namedg -rf rm namevoll

8-116

Copynqhtv 200{, Syrnantec Corporauon All nutus reserved


Restoring a File System Using Storage Checkpoints

In the beginning of this section you should have a namedgdisk group with fourunused disks in it.

Create a simple 1500m volume called origvol in the namedg disk group.vxassist -g namedg make origvol l500m

3 Make three new mount points: /orig, /checkptL and /checkpt2.

mkdir /origmkdir /checkptlmkdir /checkpt2

2 Create a VxFS tile system on the volume.mkfs -F vxfs /dev/vx/rdsk/namedg/origvol

Xote: On Linux, use mkf s - t.

4 Mount the tile system on /orig.

mount -F vxfs /dev/vx/dsk/namedg/origvol /orig

Xote: On Linux, use mount - t.

5 Write a tile of size I M named 4pmin the original file system.dd if=/dev/zero of=/orig/4pm bs=1024k count=l

6 Create a storage checkpoint named thu_5pm on /orig. Note the output.fsckptadm -v create thu_5pm /orig

7 Mount the thu _5pmstorage checkpoint on the mount point / checkpt L

mount -F vxfs -0 ckpt=thu_5pm \/dev/vx/dsk/namedg/origvol:thu_5pm /checkptlXote: On Linux, use mount - t.

8 Write some more files in the original file system on /orig, and synchronizethe tile system using the following commands:dd if=/dev/zero of=/orig/5pm bs=1024k count=5dd if=/dev/zero of=/orlg/5pm 2 bs=1024k count=5sync; sync

9 Create a second storage checkpoint, called thu spm,on /orlg. Note theoutput.fsckptadm -v create thu 6pm /orig

10 Mount the second storage checkpoint on the mount point /checkpt2.

Lab 7 Solutions: Point-in-Time Copies 8-117Copyright :t, 20[16 Syrnanlec Cnrooranon All nqtus reservec

mount -F vxfs -0 ckpt;thu6pm \/dev/vx/dsk/namedg/origvol:thu_6pm /checkpt2Note: On Linux, use mount - t.

11 Write some more files in the original tile system on /orig. and synchronizethe file system using the following commands:

dd if;/dev/zero of;/orig/6pm bs;1024k count;6dd if=/dev/zero of=/orig/6pm_2 bs=1024k count=6sync;sync

12 View the checkpoints and the original file system.

Is -1 /orig /checkptl /checkpt2

13 To prepare to restore from a checkpoint, unmount the original file system andboth storage checkpoints.umount Icheckptlumount /checkpt2umount lorig

14 Restore the file system to the thu _ 6pm storage checkpoint.

fsckpt_restore -1 /dev/vx/dsk/namedg/origvol

15 Run the fsckpt_restore command again. Note the output.

The output shows that the former UNNAMED root fileset was removed, andthat the second checkpoint (thu 6pm) is now the primary fileset. I hethu _ 6pm flleser is now the fileset that will be mounted by default. Thefirst checkpoint, thu _ SpIll, still exists, because it was taken earlier thanthe second checkpoint.

When you roll back 10 a checkpoint. carlier checkpoints still exist, whileany checkpoints taken later than thu _ 6pm would haw been lost.

Control-D to exit the fsckpt restore command.


vxdg destroy namedg


Copyright 1- 2006 Symamer: Corporanuu All II;;I'IS reserved

Optional Lab ExercisesThe next set of lab exercises is optional and may be performed if you have time.These exercises provide additional practice in exploring storage checkpoints.

Optional Lab: Storage Checkpoint Behavior

In this exercise. you perform and analyze four types of file system operations:

A tile to be deleted (lk . to_de lete)

A file to be replaced by (new) content (lk . to_replace)

A file to be enlarged (lk5. to_append)A tile to be written by databases (1 Om. db _ Lo: the tile remains at the sameposition with the same size. but some blocks within it are replaced)

Create a disk group named xdg with four disks.

vxdg init xdg xdg01=device_tagl xdg02=device_tag2xdg03=device_tag3 xdg04=device_tag4

2 Create a 12S-MB mirrored volume with a log. Name the volume xvol. Mountthe volume at /xvol.

vxassist -g xdg make xvol 128m layout=mirror,logmkfs -F vxfs /dev/vx/rdsk/xdg/xvolmkdir /xvolmount -F vxfs /dev/vx/dsk/xdg/xvol /xvol

3 Add these four new files to the volume and view the files:

lK named /xvol/lk.to delete

lK named /xvol/lk.to_replace

3B=1536bytes named /xvol/lk5.to_append

10M named /xvol/lOm.db_io

Solaris mkfile 1k /xvol/1k.to -delete

mkfile 1k /xvol/1k.to ._rep1ace

mkfi1e 3b /xvo1/1k5.to __appendmkfi1e 10m /xvo1/10m.db

-io

II P-LX dd if=/dev/zero of=/xvo1/1k.to -delete bs=1024count=ldd if=/dev/zero of=/xvo1/1k.to --

replace bs=1024count=ldd if=/dev/zero of=/xvo1/1k5.to _append bs=1536count=ldd if=/dev/zero of=/xvo1/10m.db - io bs=1024kcount=10

Lab 7 Solutions: POint-in-Time Copies B-119

Copynghl:& 2006 Symantac Corporanon All rights reserved

Is -1 /xvol

total 20488-l·W- - - - --T- rw- - - - --T-rw------T- rw- - - - --T

drwxr-xr-x

rootrootrootroot

2 root

otheror he rotherotherroot

10485760 Oct 20 14:11 10m.db io1536 Oct 20 14:10 lk5.to_append1024 Oct 20 14:08 lk.to delete1024 Oct 20 14:08 lk.to replace

96 Oct 20 14:04 lost+found

Note: This example output is from a Solaris platform. The output may beslightly different on other plauorms.

4 Remount /xvol and run ncheck.

mount -F vxfs -0 remount /dev/vx/dsk/xdg/xvol /xvolncheck -F vxfs -0 sector= /dev/vx/rdsk/xdg/xvol

STRUCTURAL 64 999 70-77 <inode alloc unit>STRUCTURAL 65 999 97 2640 2655 <inode - list>STRUCTURAL 66 999 - 2696 -2703 <inode -alloc unit>STRUCTURAL 67 999 99 422·1-4351 <inode -list>STRUCTURAL 68 999 4160-4223 <link count tbl>STRUCTURAL 69 999 2656-2671 <bsd_quota>STRUCTURAL 70 999 2672-2687 <bsd_quota>

STRUCTURAL 97 999 65 2640-2655 <inode - list>STRUCTURAL 99 999 67 4224-4351 <inode lisl>

UNNAMED 999 4 2768-2769 /lk.todeleteUNNAMED 999 5 - 4144-4145 11k.to _replaceUNNAMED 999 6 2784-2787 /lk5. to _appendUNNAMED 999 2800-2801 /lOrn. db - ioUNNAt·1ED 999 7 4352-24061 110m.db - ioUNNAMED 999 7 2816-3583 /lOrn. db ioUNNAMED 999 999 2690-2691 <attribute inode>

"lute: This example output is Irom a Solari, platform. The output of thencheck command may be slightly different Oil other platforms.

5 Create a storage checkpoint for /xvol named CKPT.fsckptadm create CKPT /xvol

6 Delete the file lk. to delete.

rm /xvol/lk.to delete

7 Create a new IK tile named lk. to_replace.

Solaris mkfile lk /xvol/lk.to - replace

HP-UX dd if=/dev/zero of=/xvol/lk.to - replace \bs=1024 count=l

B-120 VERITAS Storage Foundetion B.O for UNIX: Maintenance

Copyopru :;; 20IJ6 Sym<lllit:!t Con.crancn All nyhls reserved

8 Copy the Ik5. to_append file to /tmp.

cp /xvol/lkS.to append /tmp

9 Add the Ik5. to_append file in /tmp to the originallk5. to_appendfile in /xvol.

cat /tmp/lkS.to append » /xvol/lkS.to append

10 Use the following Perl command to generate database-like I/O (modifying ablock within a database file).

The second line opens read/write access to the tile without recreating it orsimply appending new data.

The third line creates a variable containing XK "x",

The next line positions the file pointer at XOK offset from the beginning ofthe tile.

The following line writes at this position the new XK block.

perl -e '

> open(FH, "+< /xvol/lOm.db_io") II die;> $Block="x" x 8192;> sysseek(FH,8192,O);> syswrite (FH, $Block, 8192,0) ;> close(FH);'

11 Remount /xvol and run /ncheck.

mount -F vxfs -0 remount /dev/vx/dsk/xdg/xvol /xvol

Lab 7 Solutions: Point-in-Time Copies 8-121Copyright e- 2006 Symantec Corporation All nqnts reserved

ncheck -F vxfs -0 sector= dev/vx/rdsk/xdg/xvol

STRUCTURAL 64 999 70-77 <inode alloe unit>STRUCTURAL <inode

-65 999 97 2640-2655 -list>STRUCTURAL 66 999 2696-2703 <inode -alloe -unit>STRUCTURAL 67 999 99 4224-4351 <inode

-list.>

STRUCTURAL 68 999 - 4160-4223 <link count tbl>STRUCTURAL 69 999 2656-2671 <bsd_quota,>STRUCTURAL 70 999 2672-2687 <bsd_quota::.

STRUCTURAL 74 1000 2776-2783 <iIlode alloe unit>STRUCTURAL 75 1000 76 24096 -24111 <inode - list>STRUCTURAL 76 1000 75 24096-24111 <inode _. list>STRUCTURAL 77 ]000 2792-27~9 <inode alloe unit>STRUCTURAL 78 1000 79 24192-24319 <inode - list>STRUCTURAL 79 1000 78 24192-24319 <.inode - list>STRUCTURAL 80 1000 24128-24191 <link -count -cbl>STRUCTURAL 81 1000 24112-24127 <bsd quota>STRUCTURAL 82 1000 24320-24335 ebsd___quota>STRUCTURAL 97 999 65 2640-2655 <inode

-list>

STRUCTURAL 99 999 67 4224-4351 <inode - list>

UNNAMED 999 24:336-24337 /lk. to replaceUNNAMED 999 24062-24063 /lkS.to -appendUNNAMED 999 rl84-2787 11kS.to -appendUNNAMED 999 7 2300-2801 110m .db ioUNNM1ED 999 7 4352-24061 /1001. db ioUNNAMED 999 7 2816-3583 /lOrn. db ioUNNAr~ED 999 2 999 2690-2691 <at.tribute inode>CKPT 1000 4 2768-2769 11k.co_deleteCKPT 1000 5 4144-4145 11k.to replaceCKPT 1000 6 4146-4l<l7 Ilk5.to -appendCKPT 1000 24352·24367 /l Om.db io

mkdir /ckptmount -F vxfs -0 ckpt=CKPT \

/dev/vx/dsk/xdg/xvol:CKPT /ckptls -1 /ckpttotal 22

'"f".V ·T 1 root ether··rN- ·T 1 rout other-I".,,· .. ···T 1 root other··('I./··_····_··T 1 root othe.drwxr -xr-x

., root rootc

IU4857(j(J Jun 0 14:00 -10rndb~!01536 Ju,! 9 14:00 1k5 to appu!ci1024 Jun 914:00 1k.to_delete'1()2'; Jun ') 14:00

9l) .Jun 9 1j:Sl)

ls -1 /xvoltotal 20488


C,-,pynghl i: 7006 Svmantec Corpcratron 1\11nqtus reserved

..r\!\'··_R_RRT root othPf 1()485760JU!l 'J 14:16 Uni.db .... IU

·rw-·----T roo: other 3072 Jun 9 14:14 kS.to (,~ppend-rN-----:r root other 1024 Jun \) 14:14 k.to ,repi8cerlrwxr-xr-x root runt 96 lun 11 1'35,] ost+tound

Examination of Storage Checkpoint Behavior

The following iuformation is an analysis of the previous output from ncheck:

• 1k. to deleteSame data blocks (276~-2769) mapped to CKPT

• 1k. to replaceOld data blocks (4144-4145) mapped. not copied. to CKPT. New data blocks(24336-24337) were written to a new location.

• 1kS.to append

Before checkpointingUNNAMED

12784 12785 12786 1 2787

After checkpointing and appending data

UNNAMED

12784

12785

12786

12787 124062 124063

CKPT

12784

12785

14146 14147

To get the UNNAMED file system. which is normally the active one, ascontiguous as possible. a copy-before-write of the middle block is performed.Otherwise copy-before-write would be unnecessary in favor of simple addressmapping.

Note: Blocks 27R4-27R5 arc mapped to both UNNAMED and CKPT. This is notshown in the output of nc he ck.

• 10m.db ioThe data file for UNNAMED remains at the same position (1ROO-2ROI, 4352-2406 I, 2S I6-35S3).

Note: These tiles arc fragmented because the required space was notprcallocated in one extent.

Lab 7 Solutions: Point-In-Time Copies 8-123Copynghl'~ 200fi Syruante- Corporauon All nqtus reSE!fverl

The:new blocks arc written to UNNAMED. and therefore the old data must becopied to 24352-24367 (8K) before the new blocks are written. Otherwisecopy-before-write would be unnecessary in favor of simple address mapping.Note: In all cases. inodc and directory information is copied before the write.

12 Unmount the:checkpoint and the original Ii Ie system, Destroy the xdg diskgroup.umount /ckptumount /xvolvxdg destroy xdg


Copyng~ll' 2fl06 Syrnamec Coqxnauon All nqnts reserved

Appendix C

Boot Processes and VxVM Start-Up Scripts

symantec

Solaris Boot Process

VxVM and the Solaris Boot Process

Solaris Boot Process Overview

In order to troubleshoot and resolve boot disk problems, you must have aconceptual understanding ofthe Solaris boot process and the associated scripts andtiles that arc involved in booting the system and starting VxVM.

The Solaris boot process can be divided into lour main phases:Phase I: Boot PROM Phase

Phase 2: Boot Program Phase

Phase 3: Kernel Initialization Phase

Phase 4: The /sbin/init Phase

In the next sections. each otihcsc lour phases is described in detail.

C-2Copyrlytlt' 2005 Synl(llltt>c Corporal 1011 All fights reserved

VERITAS Storage Foundation 4. 1 for UNIX: Maintenance

1. Runs self tests2. Reads the boot disk label3. Reads the boot block4 Loads the bootblk program

symantcc

Phase 1: Boot PROM Phase

When you boot a Solaris system. the first phase of the boot process is the bootPROM phase. In this phase:

1 The programmable read-only memory (PROM) chip runs self-test diagnosticsto identify system information. such as hardware and memory.

2 When you type boot at the OK prompt. the system reads the boot disk label atsector O.

3 The system then reads the boot block at sectors I through 15.

4 The PROM loads the bootblk program from the boot block. The bootblkprogram is a UFS file system reader that is placed on disk by theinstallboot program.

Appendix C Boot Processes and VxVM Start-Up Scripts C-3Ccpynqnt f 7005 Svmantac Corporauon. All fights reserved

1. Runs self tests2. Reads the boot disk label3. Reads the boot block4. Loads the bootblk program

1. Loads ufsboot

2. Loads the kernel

Phase 2: Boot Program

Phase 2: Boot Program Phase

The second phase ill the Solaris boot process, the boot program phase, begins alterthe PROM successfully loads the bootblk program from the boot block.

1 The bootblk program loads the secondary boot program, uf sboot, byinvoking the command:/platform/-uname -m-/ufsboot

2 The uf sboot program loads the kernel,

C-4 VERITAS Storage Foundation 4.1 for UNIX. Maintenance

symantcc.

1. Runs self tests2. Reads the boot disk label3. Reads the boot block4. Loads the bootblk program

~Phase 3: Kernel Initialization

1. Loads ufsboot

2. Loads the kernel

1. Loads kernel modules2. Reads fete/system

3 Initializes the kernel4. Begins /sbin/init

Phase 3: Kernel Initialization Phase

The next phase in the Solaris boot process is the kernel initialization phase. Alterthe ufsboot program loads the kernel:1 The kernel begins to load the kernel modules.2 The kernel reads the jete/system file. including the following entries:

A rootdev entryA rootdev entry specifies an alternate root device. The default rootdevvalue is the physical path name of the device Oil which the boot program(bootblk) is located.foreeload entriesforeeload entries force modules to be loaded at boot time.

3 The kernel initializes itsel f and begins the / sbin/ ini t process.After the kernel loads the modules needed to read the root partition, theufsboot program is unmapped from memory. The kernel continuesinitializing the system using its own resources.

4 /sbin/init begins.

C-5Appendix C Boot Processes and VxVM Start-Up Scripts

Copyr<gllt of; 20n!} Symatuec Comoranoo. All not-ts reserved

Phase4: /sbin/init

1. Runs self tests2 Reads the boot disk label3. Reads the boot block4. Loads the bootblk program

1. Loads ufsboot2. Loads the kernel

1. Loads kernel modules2. Reads fete/system3. Initializes the kernel4. Begins /sbin/init

1. Invokes run controlscripts

2. Single-user scripts3. Multiuser scripts

Phase 4: The / sbin/ ini t Phase

In the final phase olthc Solaris boot process, the /sbin/init process invokesthe run control scripts that arc used to start VxVM.

Single-user startup scripts. located in / et e/ reS. d. include:S25vxvm-sysbootS30rootusr. sh (standard Solaris script)S35vxvm-startupl

S4Ostandardmounts. sh (standard Solaris script)S50devf sadm(standard Solaris script)S70bui Ldmrit tab. sh (standard Solaris script)S85vxvm-startup2

S86vxvm-reconfig

Multiuser startup scripts. located in / ete/ re2 .d. include:SOlvxfsldlic

S45vxpbx~exchangedS50vxvailS70vxatd

S750vxpal.gridnode

S75vxpal.StorageAgent

S75vxsmfd

S760vxpal.actionagent

C~6

Copyngrll .~ 2005 Symantec Corporatrou All fiyt>!S reserved

VERITAS Storage Foundation 4.1 for UNIX. Maintenance

S94vxnm-vxnetd

S95vxVtn-recover

S96vxrsyncd

Nute: Scripts added by VxVI\1 are highlighted in bold. The function of each scriptis described in the next section.

------ •..~-----------------~--~----------------------------Appendix C Boot Processes and VxVM Start-Up Scripts C-7

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symantec

VxVM Startup Scripts: Single User

r/etc/rcs.dl• S25vxvrn-sysboot• S30rootusr.sh• S3Svxvm-startupl• S40standardmounts.sh• SSOdevfsadm• S70buildmnttab.sh• S85vxvrn-startup2• S86vxvm- reconfig

S2Svxvm-sysbootChecks root and lusr

• Starts the restore daemonStarts vxconfigd in bootmodeCreates disk access recordsScans the vol boot file

• Imports the boot disk groupStarts rootvoland uarvolumes

S30rootusr.shMounts lusr as read-onlyusing/etc/vfstab

• Checks fusr

VxVM Startup: Single-User Scripts

/etc/rcS.d/S25vxv.m-sysboot

The 82 5vxvm··sysboot script:Checks to determine if rootdev and /usr arc volumesI r rootdev and / usr arc volumes, thcn vxconf i gd must successfully startfor / and /usr to be accessible.Starts the V.xVM restore daemon by invoking tile command:vxdmpadm start restore optionsNote: 13ydefault. the restore daemon checks the health of disabled device nodepaths (policy=check_ disabled) at a polling interval of 300 seconds(interval=300). 13yusing options to the vxdmpadmstart restorecommand, you can change the polling interval (interval=seconds) orchange the policy to check all paths (policy=check_all).

Starts vxconf igd in boot mode by invoking the command:vxconfigd -m bootThe script includes example option strings to enable different aspects ofvxconf igd logging.Creates disk accessrecords lor all devicesLocales and imports the boot disk groupStarts the rootvol and usr volumes

C-8 VERITAS Storage Foundation 4.1 for UNIX: Maintenance

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/etc/rcS.d/S30rootusr.sh

The S30rootusr. sh script:Mounts /usr as read-onlyChecks for any problems with /usr

The /etc/vfstab tile is used to mount the /usr tile system. If /etc/vfstabincludes / dev/vx/ dsk/usr and / dev/vx/rdsk/usr as the devices for the/usr file system. then Vx VM must be running for the mount to succeed.

If /usr fails to mount. then utilities, such as fsck and Ls , are not available foruse in other scripts.

C-9Appendix C Boot Processes and VxVM Start-Up Scripts

Copyright's 2005 Svmantec Corporation All fights reser~f>rl

S35vxvm-startuplStarts special volumes.such as swap and /var

• Sets up dump devices

• S25vxvm-sysboot• S30rootusr.sh• S35vxvm-startupl

S40standardmounts.sh• SSOdevfsad.m

S70buildmnttab.sh• S85vxvm-startup2• S86vxvm-reconfig

S40standardmounts.shMounts /proc

• Adds a physical swap device• Remounts root and /usr

S50devfsadmConfigures /devandIdevices trees

S70buildmnttab.shMounts file systems. such as/var, /var/adm, and/var/run

/etc/rcS.d/S35vxvm-startupl

The S35vxvm-startupl script:

Starts special volumes. such as swap, /var. /var/adm. and/usr/kvm.

Sets up dump devices

~ole: I I' the firs: swap device is a volume. then it is used as the dump device.

Dump devices arc used to store core files that arc created when the systempanics. Con: Ii lc creation and recovery are performed completely outsideofVxVM.

The swap device must be the first swap device listed in /etc/vfstab.

The dump device requires a physical partition underneath the swapvolume.

Vx VM docs not have hooks Ior dumping, therefore the swap device mustbe created to enable thc dump device to be created.

The first swap device is registered as thc dump device. The dump device is"registered' by adding and removing the swap device.

/etc/rcS.d/S40standardmounts.sh

The S40standardmounts. sh script:

Mounts /proc

Adds the physical swap device

Volume Manager handles all volumes in the / etc/vf stab file that havea file system type of swap as swap volumes.


Copvnqm >. 2005 Svrnantec Corporanon. 1\11nqnts reserved

Checks and remounts the root tile system as read-write

Checks and remounts /usr as read-write

/etc/rcS.d/SSOdevfsadm

The S50devfsadm script configures the /dev and /devices trees,

/etc/rcS.d/S70buildmnttab.sh

The S70buildmnttab. sh script mounts file systems that arc required to beavailable in single-user mode: /var, /var / adm.and /var /run,

Note: I\. swap device is mounted as /var /run.

C--11Appendix C Boot Processes and VxVM Start-Up Scripts

COPYright c 2(105 Svrnanter Corporation All nqms reserved

'symante(_

S85vxvm-startup2Starts I/O daemonsChanges vxconfigd toenabted mode

• Imports disk groups markedfor autoimportInitializes DMPReattaches drives

• Starts all volumes

S86vxvm-reeonfigPerforms operationsdefined by vxinstall andvxunroot

• Uses flag files to determineactionsAdds new disks

• Performs encapsulation

/ete/reS.d/S2Svxvm-sysboot

• S30rootusr.shS35vxvro-startuplS40standardmounts.sh

• SSOdevfsadm• S70buildmnttab.sh• S85vxvm-startup2

S86vxvm-reconfig

/etc/rcS.d/S8Svxvm-startup2

The S85vxvm-startup2 script:

Starts 110 daemons by invoking the command:

vxiod set 10Changes vxconf igd from boot mode to enabled mode:vxdct1 enableThe dev info tree is scanned for new entries.

Imports all disk groups marked for autoimport

lnitializcs OM/, by invoking the command:vxdc t1 ini tdmp

Reattaches drives that were inaccessible when vxconf igd first started:vxreattachStarts (but docs not recover) all volumes:

vxrecover -n -s

/etc/rcS.d/S86vxvm-reconfig

The S86vxvm- reconf ig script is used to perform operations defined byvxinstall and vxunroot and is used as part of upgrade procedures.

This script:

Uses flag files to determine actions

The / etc/vx/reconf ig. d/ state. d directory contains entries ofprior actions.

C-12 VERITAS Storage Foundation 4.1 for UNIx.- Maintenance

Ccpynqht o 2005 Syrnamec ccroorenco All fights reserved

The encapsulation process requires a reboot and creates flag files forfurther actions.If encapsulation is incomplete. you must remove the !lag files manually.The root_done flag tile provides information on whether the root disk isencapsulated and can exit without any action.

Adds new disksDisks selected for initialization by vxinstall are initialized.Performs encapsulationA reboot is required if the root file system or a mounted tile system isencapsulated.

Appendix C Boot Processes and VxVM Start-Up Scripts C-13(,Opyrlg~11 r: 2005 SyrnantecComo-anon fI!1 ngl:iS reserveo

svrnanrec

S45vxpbx_exchanged• SSOvxval1• S70vxatd• S73isisd• S750vxpal.gridnode• S75vxpal.StorageAgent

• Loads the vxportal kernelmodule

• Enables VXFS specialfeatures by running thevxenablef command.

These scripts are used tostart various infrastructurecomponents for VxVM, suchas the agents used by thestorage foundationmanagement server or VEA,the VEA server, and so on.

These scripts are used tostart various daemons andprocesses used by VeritasVolume Replicator. Theyrequire a valid WR license.

• S94vxnm-vxnetdS96vxrsyncd

• S96vradmind• S95vxvm-recover

S95vxvm- recover Starts volume recovery andresynchronization and hot relocation daemons

VxVM Startup: Multiuser Scripts/etc/rc2.d/S94vxnm-vxnetd and /etc/rc2.d/S96vxrsyncd

These scripts start various daemons and processesthat arc used by the VeritasVolume Rcplicator software. Both of these scripts require a valid VVR license in/etc/vx/licenses/lic.

/etc/rc2.d/S95vxvm-recover

The S95vxvm-recover script:Starts recovery and rcsynchronization on all volumesStarts hot-relocation daemons

To enable hot-relocation notification for an account other than the localroot account. you must modify this script.Disabling the hot-relocation daemon vxrelocd results in no hotrelocation and no notification.

C--14 VERITAS Storage Foundation 4.1 for UNIX: Maintenance

Copyright 20U5 Syrnautec Cospurauon Alluqhts reserved

symantec.

HP-UX Boot Process

VxVM and the HP-UX Boot Process

HP-UX Boot Process Overview

In order to troubleshoot and resolve problems that affect VxVM and the boot diskgroup, you must have a conceptual understanding of the II P-UX boot process andthe associated scripts and tiles that are involved in bouting the system and startingVxVM.

The I-IP-UX boot process can be divided into three main phases:Phase I: POST PhasePhase2: Bootstrap PhasePhase3: Initialization Phase

These phasesare described in the following sections.

Appendix C Boot Processes and VxVM Start-Up Scripts C-1SCopyright © 2005 Symantec ccrro-euon. All fights reserved

symantec.

Phase 1: POST Phase

&----11. Runsself tests'-- ,...••••• ,.jj 2. Initializesthe processor

Phase 1: POST Phase

When you boot an HP-UX system, the first phase of the boot process is the POSTphase. In this phase, the processor-dependent code (PDC), performs sel I-restdiagnostics and initializes the processor.

lfthc autoboot and autosearch parameters arc enabled in firmware, the bootprocess wi II enter the bootstrap phase automatically. II' these parameters arc notset. or if you interrupt the autoboot process by pressing the Ese key, you caninteract with the boot program. When you interact with the boot program, you can:

Boot using a specific device.

Search fur boot devices.

Change boot parameters.


Copynyht •. 2005 Symantec COfPOfi1l1uPAll nurus reserved

Phase 2: Bootstrap Phase

•..•---11, Runs self tests""' ••••••••••••_,.... •••• ••• 2, Initializes the processor

POST Phase

1, Transfers control to theinitial system loader (ISL)

Bootstrap Phase •..•---1 2, Transfers control to the""'-_ ••••_,....-_ ••••_... hpux bootstrap loader

3, Loads the HP·UX kernel

Phase 2: Bootstrap Phase

symantec.

The second phase in the IIP·UX boot process is a two-part bootstrap operation:

Part one of the bootstrap process begins after the POL successfully loads andtransfers control to the operating system-independent initial system loader(ISL)

2 Part two of the bootstrap process begins when the ISL loads and transferscontrol to a HP-UX-specitic bootstrap loader utility called hpux. The hpuxutility loads the IIP-UX kernel (/ s tand/vmunix) and transfers control to theloaded kernel image.

Appendix C Boot Processes and VxVM Start-Up Scripts

Copvnqtn ~ 2005 Syrnantec Corpo.aroo All notus reserved

C-17

Phase 3: Initialization Phasesymantec

L Transfers control to theinitial system loader (ISl)

1---.., 2. Transfers control to the'- .,..; .a hpux bootstrap loader

3. loads the HP-UXkernel

•... ---1 1. Runs self tests""'----'1"'- .....---. 2. Initializes the processor

1. Executes/sbLn/pre init rc1.~~!!!!!!:!!!:!=~!,._t"--12.Begins Isbin/init

3. Init executes ioini trc,vxvrn-sysboot, andvxvm-startup

4. Init executes other singleuser and multiuser VxVMstartup scripts.

Phase 3: Initialization Phase

After the kernel initializes, it executes the / sbin/pre _ini t _rc command andthen starts the / sbin/ ini t process, which executes the startup scripts found inthe /etc/inittab file,

The following scripts arc executed during the first part of the initialization phase:/ sbin/pre _ini t _rc: This script checks if root is a VxVM volume bychecking the existence or / sbin/ is _vxvmroot file, and executes it if theliie exists. The vxconf igd daemon is started in boot mode before the rootfile system is checked./sbin/ioinitrc: This script checks if the system is running from a localroot and itso. mounts the boot file system (/stand). It usesthe/ sbin/ is _vxvmroot tile to check if the boot rile system is on a VxVMvolume.

/ sbin/ ini t ,d/vxvm- sysboot: This script con ligures the / and/ stand volumes as needed. enables vxconf igd logging, and starts theDI\1r restore daemon./ sbin/ ini t ,d/vxvm- start up: Starts some I/O daemons, rebuilds/ dev/vx/ [r 1d s k. imports all disk groups, and starts all volumes that werenot started earlier in the boot sequence.


Copynght~, 2005 Svovernec Corporancn All lights resprved

symantcc.

Start-up Scripts: Single User

I/Sbin/initl----lS091vxvrn-nodes-check

Checks and creates the requiredVxVM device files

The VxVM-rciated startup scripts under /sbin/rcl. d directory arc:

S091vxvm-nodes-check: This script is linked to/ sbin/ ini t . d/vxvm-nodes - check. It checks and creates the requiredVxVM device files.

S092vxvm-startup: This script is linked to/ sbin/ ini t . d/vxvm- start up. It starts some 1/0 daemons, rebuilds/ dev / vx/ [r 1d sk, imports all disk groups, and starts all volumes that werenot started earl ier in the boot sequence.

S093vxvm-reconfig: This script is linked to/ sbin/ ini t . d/vxvm- reconf ig. It carries out any reconfiguration taskssuch as conversions from L.VM to VxVM.

/sbin/rcl.d/S091vxvrn-nodes-checkS092vxvm-startup ---+- so 92vxvrn- startupS093vxvm-reconfig • Starts I/O daemons

Rebuilds device directories• Imports all disk groups

Starts all volumes (withoutany recovery)

S093vxvrn-reconfigCarries out anyreconfiguratlon tasks suchas conversions from LVM toVxVM.

----------------------~--~-------~-----------~----Appendix C Boot Processes and VxVM Start-Up Scripts C-19

Start-up Scripts: Single User

Cooynotu 't, 2()US Svmantec Corpcraucn All nqtn" reserveo

Start-up Scripts: Multiusersyrnantec

I/abin/init~

/sbin/rc2.d/S096vxvm-recover------

• 8994vxnm-vxnetdS996vradmind

• S996vxrsyncd• S450vxpbx_8xchanged• SSOOvxvail• S100isisd• S700vxatd

S750vxpal.StorageAgent• S750vxpal.gridnode

B751vxamfdS760vxpal.actionagent

BaCk.1

- S096vxVIn-recoverAttaches stale plexesRecovers plex synchronizationExecutes vxrecover

• Starts vxrelocd,vxconfigbackupd, and vxcached

These scripts are used tostart various daemons andprocesses used by VeritasVolume Replicator. Theyrequire a valid VVR license.

,~ These scripts are used toI start various daemons and

processes used by VeritasVolume Replicator. Theyrequire a valid VVR license.

Start-up Scripts: Multiuser

The Vx VM-related startup scripts under / sbin/ rc2 .d directory are:

S096vxvm-recover: This script is linked to/sbin/init .d/vxvm-recover. It attaches plcxcs, as needed, executesthe vxrecover command. and starts the volumeManager watch daemons.S994vxnm-vxnetd, S996vradmind. S996vxrsyncd: These scriptsarc related to VERITAS Volume Rcplicator and arc nut used unless there is avalid VVR license.

S7 00i s isd: This script is linked to / sbin/ ini t .d/ i s isd. It starts theVEA server.

The rest of the scripts arc used to start various infrastructure components lorVxVM. such as the agents used tor the Storage Foundation ManagementServer or V EA.

C-20 VERITAS Storage Foundation 4. 1 for UNIX: Maintenance

Copvnqht '. 2005 Symantec Coeporancn All fights reserved

Index

Files and Directories/dcv'vxconfig 2-4/dcv/vx.dsk 2-10'dcv/vxdsk/usr C-9'dev/vx/rdsk 2-10'dev/vx/rdsk/usr C-9'etc/defauh-vxse 5-25letc'rc2.d/S95vxvlll-rccovcr C-14'etcircS.d!S25vxvm-sysboot C-8'ctc'rcS.diS:10rootusr C-9/etc 'rcS.d.'S:15yxvlll-startupI C-l0!ctc'rcS.d/S40standardmounts C-l0etc/rcS.(f/S50devfsadlll C-l1ere 'rcS.d 'S70buildmnttab C-ll

!etc'rcS.d!S85vx YIll-startup2 C-12!etc,rcS.d/SR6vxvm-recon fig C-12/etcsystcm 3-23, 4-4, C-5

forceload entries 4-11troubleshooting 4-11using an alternate 4-12

/ctcvfstab 3-23, 4-4, C-9/ctc/vx/elm 4-4, 4-8/ctc/vxTiccnsesTic 4-4, 4-8'ctc/vx/rcconfig.dstatc.d C-12'etc/vx-rccnufig.d/srate.d/insrull-db 4-4, 4-6/erc/vx/volboot 2-3, 4-4

troubleshooting 4-7/opt '\'RTS/vxsc/yxvlll 5·23'proc C.l0!sbininit phaseC-6

.siand/vmunix C·17/usr C·8/usr.kvrn C·l0/var C·l0, C-l1/var/adm C-l0, C·l1/varadrnvx/veacmdlog 5·12'vat/run C·l1/var.vxvrn/rempdb 4·4, 4·9!VXVM#.#.II·UPGRADEI.start runed 4·4, 4·6

Copvnqm,,- ~006 Svmantec Cotprxat.nu fl.11nqnts reserved

fndex-l

A

aborting online rclayout 5·8ACTIVE 1·5active path attribute 2·19ACTIVE state 1·13, 1·16acrivcactive disk arrays 2·17activepassive disk array 2·17adaptive 1'0 policy 2·18allocation policies 8·7alternate boot disk

creating 3·18creating ill CLI 3·19creating in VEA 3·18creating in vxdiskudm 3·18

alternate mirrorbooting 3-21

analysis toolsvxstat 6·6vxtrace 6·6

analyzing drive performance 6-8analyzing the application 1'0 profile 6·11application volumes 8·13application workload

analyzing 6·4architecture or Vx VM 2·3array

activeactive 2·17activepassive 2·17adding support for 2·14removing support for 2·14

atomic-copy resynchronization 1·4. 1-21auto

cdsdisk 2·8simple 2·8sliced 2·8

auto disk type 2·8

B

bad block rcvectoring 3·9balanced 1'0 policy 2·18balancing load 6·9

benchmarking tools 6-6

boot device, cannot be opened 4-5

boot disk 3-8creating all alternate 3~18creating an alternate in CLI 3-19creating an alternate in VEA 3-18creating an alternate in vxdiskadm 3-18creating an emergency 4-23encapsulating 4-23encapsulating in vxdiskudm 3-14mirroring in vxdiskadm 3-18unencapsulating 3-22

boot disk encapsulation 3-8effect on eresystem 3-16effect on .etc.vtsrab 3-17file system requirements 3~11planning 3-13using vxdiskadm 3-14. 3-15viewing 3-16

boot disk errors 3-20

boot disk failurenonencupsulatcd 4-17. 4-18only disk in boot disk group 4-19other disks in boot disk group 4-20

boot disk failures 4-16

boot disk grouptemporarily importing 4-15

boot mirror verification 3·21

boot process 4-3HP-LJX C-15HP-L.X bootstrap process C-17HP-UX POST phase C-16Solaris C-2Solaris 'sbininit phase C-6Solaris boot program phase C-4Solaris boot PROM phase C-3Solaris kernel initialization phase C-5troubleshooting 4-4

boot pnlgram phase C-4

hootblk C-3. C-4

bootdg 3-13

booting from alternate mirror 3-21

cC program 6-6

cache objectcreating 7-24

calculating throughput 6-8

CDS disk 2-8

changing plex states 1-22

check all 2-24

check disabled 2-24

circular buffer 6-11

CLEAN state 1-13, 1-16

cleartcmpdir 4-9

clone 1'0018-13

command log tile 5-12

concurrency 6-13

condition tlags 1-15IOI'AIL 1-15NODEVICL 1-15RECOVER 1-15REMOVED 1-15

configuration daemon 2-4controlling 2-9

configuration database 2-4, 2-7copies 2-5disk group status 2-5log entries 2-5size 2-5

controllerenabling or disabling 1'0 to 2-23

copy-on-write 7-6

cpio 4-23

crcuting a traditional volume snapshot 7-17

creating a volume 1-10

creating an alternate boot disk 3-18

creating an emergency boot disk 4-23

Cross-Platform Data Sharing 2-8

odaemons of VxVM 2-3

data backup 7-3

data Ii re-cycle management 8-3

data pool 8-13

data storage checkpoint 7-16

dd 6-6

debugging 4-10

decision support 7-3

DLTACHlD state 1-17

device discoverypartial 2-15

Index-2 VERITAS Storage Foundation 5.0 for UNIX' Maintenance

Copyright 1:. 2006 Svrnantec Curporanon 1\11rights reservad

device name 2-6device tag 2·6dirty region log biunaps 1·8

dirty region logging 1-6, 1·7, 3·11DISABLED state 1·17disabling I/O to a controller 2·23disk

load balancing 6·9disk array

activeactive 2·17active/passive 2-17adding support for 2·14removing support tor 2·14

disk format 2·6disk formats 2·8disk group

configuration database data 2·5disk group name 2·6disk header

displaying 2-6disk header version 2·6disk media name 2-6disk status nags 2·6displaying information

instant volume snapshots 7·26storage checkpoints 7·33traditional volume snapshots 7·18

DMP 2·16benefits 2·16displaying I/O statistics 2·20preventing 2·21, 2·22restore daemon 2·24restore daemon policies 2·24setting path attributes 2·19setting the J!O policy 2·18startiug the restore daemon 2·24

drive performance 6·8DRL 1·7dump devices C·10dynamic multipathing 2·7, 2·16

benefits 2·16displaying )'0 statistics 2·20preventing 2·21,2·22restore daemon 2·24setting path attributes 2-19setting the I/O policy 2·18

E

ecprom 3·13emergency boot disk 4-23

booting from 4·24creating 4-23

EMPTY state 1·13,1·16E"JABLED state 1·17enabling 1'0 to a controller 2-23encapsulating root

benefits 3·9limitations 3·9

encapsulating the boot disk 4·23encapsulation

effect on 'ere/system3·16unencapsulating a boot disk 3·22

["J[) read disk 6-13E"JD read vdcv 6·13expired license

replacing 4·8

F

failed rootrepairing 4·15

Fasikcsync 1·6,7·10tile system snapshots

compared to checkpoints 7·15find utility 4·23Iorceload C·5forccload entries 4·11forcing a volume to start 1·21fsckptadm create 7·31fsckpiadm list 7·33fsckptadm pathinfo 7·33full-sized instant volume snapshots

off-host processing 7·27

H

high availability 3·9host If)

changing in volboot 4~7conflicting 4·7

hosiid 2·6hot-relocation daemons

starting C·14

VERITAS Storage Foundation 5,0 (or UNIX: Maintenance

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lndex-B

HP-UX boot process C·15

(,0

displaying OMP statistics 2-20enabling and disabling to a controller 2-23

LiO daemons C·121'0 generators 6·6J'O policy

setting for DMP 2·181'0 rate

controlling 5-191'0 transfer path

analyzing 6·5importing the boot disk group temporarily 4·15initializing a volume 1·10insiallboor 3-19, 4·23, C·3installp 2·14instant volume snapshots 7·8

displaying information 7·26intelligent storage provisioning 8·10ioctl tunctionst-f ?

IOFAIL tlag 1·15iopolicy 2·18

Kkernel C·5kernel initialization phase C-5

kernel log 2-10kernel logs 2·7kernel Slates 1·17

DI:TACHLD 1·17DISAI:lLLD 1·17I,NAI:lLLD 1-17

kmrunc 6·18

L

license keystroubleshooting 4-8

licensesreplacing expired 4·8

life cyclepoint-in-time copies 7·7

load balancing 6·9for overused drives 6·10

log plcx 1·7log subdisks 1-7logging 1·7

dirty region logging 1·7logical PITe 7·4

copy-on-write 7-6performance issues 7-6redirected reads 7-6

M

minimumq I '0 policy 2·18mirror

booting from alternate 3·21mirroring the boot disk 4·23

errors 3·20vxdiskadm 3·18

mounting a checkpoint 7·31, 7·32multiported disk array 2·17multiuser startup scripts C·14multi-volume tile systems 8·6

N

NITDSYNC 1·5NITDSYNC stare 1·16

nodatastorage checkpoint 7·16NO[)FVICE flag 1·15NODI'VIlT state 1·16

nomanual path attribute 2·19noncncupsulatcd boot disk failure 4·17,4·18noumountable storage checkpoint 7·16

noprefcrrcd path attribute 2·19

ooft-host processing 7 ·27

phases 7·27using point-in-time copies 7·3

OFFLINE state 1·14online rclayout 5·3

aborting 5·8and log plcxes 5-6and sparse plcxes 5·6

lndex-a VERITAS Storage Foundation 5,0 for UNIX Maintenance

Copyright' 2006 Syruants- Corpoanc« All fights reserved

and volume length 5·6and volume snapshots5·6continuing 5-8in CLI 5-9limitations 5·6monitoring 5·8pausing 5·8process 5-4reversing 5·6. 5·8supported transformations 5·3temporary storage space5·5

opt 3-10. 3·11overused drives 6·10

p

parametersYxVM tunable 6·17

parent task 5-14partial device discovery 2·15partition numbers 2-6partitions

after encapsulation 3·16PATli A·45. 6·69pausing online rclayout 5·8performance

analyzing drives 6-8measuring drive throughput 6·8

performance analysis process6·3performance analysis tools 6-6

vxsuu s-svxtrace 6-6

physical or logical PITC 7-4physical PITC 7-4

performance issues7-5PITC 7·3pkgrm 2·14plex

identifying problems 1·11resolving problems 1·19

plex kernel state 1·17plcx kernel states 1·11plcx problems

analyzing 1·24good plex is not known 1-24

plex states 1-11. 1-13ACTIVE 1·13

changing 1-22CLEA~ 1·13EMPTY 1·13OFFLI'JE 1·14SNAPATT 1·14S'JAPDONE 1·13STALE 1·14TEMP 1·14

point-in-time copies 7·3common uses7·3copy-on-write 7·6displaying information

instant volume snapshots7·26traditional volume snapshots7·18

FastResync7·10full-sized instant volume snapshots7-12instant volume snapshots7·8life cycle 7-7physical or logical copy 7-4readsand writes 7·5redirected reads 7·6space-optimized 7-8, 7·13space-optimized instant volume snapshots

creating a cache object 7·24storagecheckpoints 7·8. 7·14

creating and munaging 7·31displaying information 7-33restoring a file system 7-34

traditional volume snapshots7·9creating and managing 7·17displaying information 7·18

PostMark 6-6preferred path attribute 2·19primary path auribuie 2·19priority 1'0 policy 2·18private region 2·7private region offset 2·6PROM C·3prtconf 6·17prtvtoc 3·13PTID 5·14pubpaths 2·6

R

RAm-s lo/!/!ing 1·6random 1'0

and stripe unit size 6-12

VERITAS Storage Foundation 5,0 for UNIX' Maintenance Index-5Copyright e: 2006 Syuranter Corporation 1\11nqhts reserved

read-writcback resynchronizarion 1-5

read-writeback synchronization 1-21

RECOVER !lag 1-15

recovering the boot disk group 4-15

rclayour 5-3aborting 5-8pausing 5-8resuming 5-8reversing 5-8

Relayour Status Monitor window 5-8, 5-12

relocation policies 8-7

removable storage checkpoint 7-16

REMOVED flag 1-15

repairing tailed root 4-15

resilience levelchanging 5-11

restore daemon C-8

restoring a file system from a storage check-point 7-34

resynchronization 1-3, C-14atomic-copy 1-4read-wrireback 1-5

revectoring 3-9

reversing online rclayout 5-8

root 3-11, 3-16reparing failed 4-15

root encapsulationbenefits 3-9limitations 3-10

root plexerrors 3-20

root done C-13

roorabi Iiry 3-8

rootdev C-5. C-8

rootvol 3-10,4-12, C-8

round-robin 1,'0 policy 2-18

rpm 2-14

run control scripts C-6

sS25vxvm-sysboot C-8

S.lOrootusr C-9

S35vxvm-stal1UP I C-10

S-l()standardmounts C-10

S50de\tSadm C-11

S70buildmnttab C-11

S)\5VxYll1-startllp2 C-12

SX6vxvm-recontig C-12

S95V'XYlll-rccover C-14

scratch pad 5-4

scriptsfor VxVM startup C-6

secondary path attribute 2-19

sequential 1,0and stripe unit size 6-12

shared cache objectcreating 7-24

sinulcactive I/O policy 2-18

single-user startup scripts C-Bsliced disk 2-8

slow attribute 5-20

SNAPAIT st.ue 1-14

SNAI'DUNL state 1-13

Solaris boot process C-2

space-optimized instant volume snapshots 7-8,7-13

special volumesstarting C-1 0

STALE statc 1-14

standby path attribute 2-19

START read disk 6-13

START read vdev 6-13

starting a volume 1-10, 1-21

startup scriptsmultiuser C-14single-user C-8troubleshooting 4-6VxVM C-6

STATE fields 1-11

stateskernel 1-17plex 1-13volume 1-16

statisticsdisplaying with vxstat 6-7

storage checkpoints 7-14compared to file system snapshots 7-15creating and managing 7w31displaying information 7-33mounting 7-31

Index-6 VERITAS Storage Foundation 5.0 for UNIX: Maintenance

CUp)lroyr,J·iJ 2006 Syruanrec Coecorauon Annqnts reserved

restoring a II le system 7-34types 7-16

Storage Expert 5-21customizing default uuributes 5-25list of rules 5-26rule syntax 5-23rules 5-21rules engine 5-21types of rules 5-22

storage pools 8-13clone 1'0018-13data pool 8-13

stripe unit sizerandom I/O 6-12sequential 1'0 6-12

swap 3-8. 3-16. C-l0swapvol 3-10swrernove 2-14SYNC 1-5SYNC state 1-16system file

using an alternate 4-12

T

tag 143-16tag 153-16task

controlling 5-17controlling progress rate 5-19displaying intormauon about 5-14monitoring 5-16slowing 5·20

Task lIistory window 5-12task rhroulinj; 5-20TASKID 5-14tasks

managing 5-12managing in YEA 5-12

TEMP state 1-14template 8-13temporarily importing the boot disk group 4-15temporary storage area 5~5TEMPRM state 1-14TEMPRMSD state 1-14thronling a task 5-20

throughput calculation 6-8traditional volume snapshots 7-9

displaying infornuuion 7-18troubleshooting the boot process 4-4tunable parameters 6-17

displaying 6-17modifying 6-18

uUFS 3-11ufsboot C-4upgrade _llnish 4-6

upgrade_start 3-10. 4-6

usr 3-10.3-11. 3-16

vvar 3-10.3-11.3-16VEA

changing volume layout 5-7command log file 5-12creating an alternate boot disk 3-18Task History window 5-12ihrouling a task 5-20

\'ERITAS Storage Expert 5-21volboot 2-12

viewing contents 2-12volboot file

re-creating 4-7volume

analyzing with Storage Expert 5·21creating 1-10"nee starting 1-21initializing 1-10managing tasks 5-12online rclayout 5-3recovering 1·20starting 1-21

volume kernel state 1·17volume kernel states 1-11volume layout

changing in eLl 5·9changing in VEA 5-7changing online 5·3load balancing 6·9

volume sets 8·6

VERITAS Storage Foundation 5,0 for UNIX' Maintenance Index-7

Copvnqtu '!j; 2006 Symanter. Corporaucn 1\11nqnts reserven

volume states 1-11, 1-16ACTIVE 1-16CLI::AN 1-16EMPTY 1-16NEFDSYNC 1-16NODEVICL 1-16SYNC 1·16

volume tasksmanaging in VEA 5-12

VTOe 3-16, 3-17vxassisr 1-10vxassist convert 5-9, 5-11vxassisrmirror 3·19vxassist relayout 5·9,6-15vxbench 6-6vxboorsetup 3-19vxconfig 2·4vxcontigd 1-22,2·3,2-4,2·8,2-9,4·9,4·10,4·

24, C-8, C·12displaying status 2·11

disabling 2·11enabling 2·11

vxconfigd modes 2·10vxdcrl z-t t

vxdcrl enable 2·3,4·8, C·12vxdctl hostid 4·7vxdctl init 4·7vxdctl initdmp C·12vxdctl lisr 2·12vxdg list 2·5vxdisk list 2·7vxdisk scandisks 2·15vxdiskadm

creallng an alternate boot disk 3·18encapsulating the boot disk 3·14

vxdmp.con I' 6·17vxdmpudm getattr 2·18vxdmpadm iostar 2·20vxdmpadm scuutr 2·18, 8·24vxdmpadm start restore 2·24, C·8\XCIlCIP

encupsul.uing the boot disk 3·15VxFS 3·11vxinfo 1·12vxio.cont 6·17

vxiod 2·3, 4·24, C·12vxliccnse 4·24vxlicinsr 4·8vxmend 1-22vxmend fix 1·19, 1·22vxrncnd offl·19, 1·23vxmend (In 1·19, 1·23vxmirror 3·19vxprint 1·12, 6·8, 6·15vxreattach C·12vxrecover 1·19, 1·20,4·15,4·24, C·12vxrelayour 5·13, 5·18vxrelayour reverse 5·18vxrelayour starr 5·18vxrclayout status 5·18vxrclocd 2·3, C-14vxrootmir 3·19VxSI: 5-21vxsuu 6·6, 6-7, 6-8, 6-9, 6·10vxrask 5·13, 5-17vxrask abort 5-17vxrask list 5-14, 5·15\ xrask monitor 5-16vxtask pause5·17vxtask resume5·17vxtrace 6-6, 6-11, 6-14, 6·15

interpreting output 6-13vxunroor 3-22V,VM

architecture 2·3configuration database2-4daemons2-3

VxVrv,l startupsingle-user scripts C-8

V \ V M startup scripts C·6multiuser C-14troubleshooting 4-6

vxvol init 1-10vxvol sla.11-16, 1-19, 1-21

lndex-B VERITAS Storage Foundation 5,0 for UNIX: Maintenance

Cnryflghl 'f 2006 SyrnautecCorporaucn All fights reserveo

Bheritaas5 foundation

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