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N281842
Veritas NetBackup
Backup Planning and
Performance Tuning Guide
UNIX, Windows, and Linux
Release 6.0
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Veritas NetBackup NetBackupBackup Planning and Performance Tuning Guide
Copyright 2003 - 2006 Symantec Corporation. All rights reserved.
Veritas NetBackup 6.0PN: 281842
Symantec, the Symantec logo, and NetBackupare trademarks or registered trademarks ofSymantec Corporation or its affiliates in the U.S. and other countries. Other names may betrademarks of their respective owners.
Portions of this software are derived from the RSA Data Security, Inc. MD5Message-Digest Algorithm. Copyright 1991-92, RSA Data Security, Inc. Created 1991. Allrights reserved.
The product described in this document is distributed under licenses restricting its use,copying, distribution, and decompilation/reverse engineering. No part of this documentmay be reproduced in any form by any means without prior written authorization ofSymantec Corporation and its licensors, if any.
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Symantec Corporation20330 Stevens Creek Blvd.Cupertino, CA 95014www.symantec.com
Printed in the United States of America.
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Contents
Section I Backup planning and configuration guidelines
Chapter 1 NetBackup capacity planning
New .........................................................................................................................12
Introduction ..........................................................................................................13
Analyzing your backup requirements ..............................................................14
Designing your backup system ..........................................................................16
Calculate the required data transfer rate for your backups ..................17
Calculate how long it will take to back up to tape ...................................18
Calculate how many tape drives are needed ............................................20Calculate the required data transfer rate for your network(s) .............21
Calculate the size of your NetBackup catalog .........................................22
Calculate the size of the EMM server ........................................................23
Calculate how much media is needed for full and incremental backups 25
Calculate the size of the tape library needed to store your backups ...26
Design your master backup server based on your previous findings ..27
Estimate the number of master servers needed ......................................29
Design your media server ...........................................................................31Estimate the number of media servers needed .......................................32
Design your NOM server .............................................................................33
Summary .......................................................................................................36
Questionnaire for capacity planning ................................................................37
Chapter 2 Master Server configuration guidelines
Managing NetBackup job scheduling ................................................................40Delays in starting jobs .................................................................................40
Delays in running queued jobs ...................................................................40
Job delays caused by unavailable media ...................................................41
Delays after removing a media server ......................................................41
Limiting factors for job scheduling ...........................................................41
Adjusting the servers network connection options ...............................42
Using NOM to monitor jobs ........................................................................ 43
Disaster recovery testing and job scheduling ..........................................43Miscellaneous considerations ............................................................................44
Processing of storage units ........................................................................44
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Disk staging .................................................................................................. 44
File system capacity .................................................................................... 45NetBackup catalog strategies ............................................................................ 45
Catalog backup types .................................................................................. 46
Guidelines for managing the catalog ........................................................ 46
Catalog backup not finishing in the available window .......................... 47
Catalog compression ...................................................................................48
Merging/splitting/moving servers ................................................................... 48
Moving the EMM server .............................................................................. 49
Guidelines for policies ........................................................................................ 49Include and exclude lists ............................................................................ 49
Critical policies .............................................................................................50
Schedule frequency ..................................................................................... 50
Managing logs ...................................................................................................... 50
Optimizing the performance of vxlogview .............................................. 50
Interpreting legacy error logs .................................................................... 51
Chapter 3 Media Server configuration guidelinesNetwork and SCSI/FC bus bandwidth ............................................................... 54
How to change the threshold for media errors ............................................... 54
Adjusting media_error_threshold ............................................................. 55
How to reload the st driver without rebooting Solaris .................................. 57
Media Manager drive selection ......................................................................... 58
Robot types and NetBackup port configuration ............................................. 58
Chapter 4 Media configuration guidelines
Dedicated or shared backup environment ....................................................... 60
Pooling ...................................................................................................................60
Disk versus tape ...................................................................................................60
Chapter 5 Database backup guidelines
Introduction ......................................................................................................... 64Considerations for database backups ............................................................... 64
Chapter 6 Best practices
Best practices: new tape drive technologies .................................................... 66
Best practices: tape drive cleaning ................................................................... 66
Best practices: storing tape cartridges ............................................................. 68
Best practices: recoverability .............................................................................68
Suggestions for data recovery planning .................................................. 69
Best practices: naming conventions ................................................................. 71
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Policy names .................................................................................................71
Schedule names ............................................................................................72Storage unit/storage group names ............................................................72
Section II Performance tuning
Chapter 7 Measuring performance
Overview ................................................................................................................76
Controlling system variables for consistent testing conditions ...................76Server variables ............................................................................................76
Network variables ........................................................................................77
Client variables .............................................................................................78
Data variables ...............................................................................................78
Evaluating performance .....................................................................................79
Evaluating UNIX system components ..............................................................84
Monitoring CPU load ...................................................................................84
Measuring performance independent of tape or disk output ...............84Evaluating Windows system components .......................................................85
Monitoring CPU load ...................................................................................86
Monitoring memory use .............................................................................87
Monitoring disk load ...................................................................................87
Chapter 8 Tuning the NetBackup data transfer path
Overview ................................................................................................................90The data transfer path ........................................................................................90
Basic tuning suggestions for the data path .....................................................91
NetBackup client performance ..........................................................................95
NetBackup network performance .....................................................................96
Network interface settings .........................................................................96
Network load .................................................................................................97
NetBackup media server network buffer size ..........................................97
NetBackup client communications buffer size ........................................ 99The NOSHM file .........................................................................................100
Using multiple interfaces .........................................................................101
NetBackup server performance .......................................................................102
Shared memory (number and size of data buffers) ..............................102
Parent/child delay values .........................................................................108
Using NetBackup wait and delay counters ............................................108
Fragment size and NetBackup restores ..................................................119
Other restore performance issues ...........................................................122NetBackup storage device performance .........................................................126
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Chapter 9 Tuning other NetBackup components
Multiplexing and multi-streaming .................................................................130
When to use multiplexing and multi-streaming ...................................130
Effects of multiple data streams on backup/restore ............................ 132
Encryption ..........................................................................................................133
Compression .......................................................................................................133
How to enable compression .....................................................................133
Using both encryption and compression .......................................................134
NetBackup java ...................................................................................................134Vault ....................................................................................................................134
Fast recovery with bare metal restore ............................................................135
Backing up many small files ............................................................................135
FlashBackup ...............................................................................................136
Chapter 10 Tuning disk I/O performance
Hardware performance hierarchy ..................................................................140
Performance hierarchy level 1 ................................................................142Performance hierarchy level 2 ................................................................142
Performance hierarchy level 3 ................................................................143
Performance hierarchy level 4 ................................................................144
Performance hierarchy level 5 ................................................................145
General notes on performance hierarchies ...........................................145
Hardware configuration examples .................................................................147
Tuning software for better performance ....................................................... 148
Chapter 11 OS-related tuning factors
Kernel tuning (UNIX) ........................................................................................152
Kernel parameters on Solaris 8 and 9 ....................................................152
Kernel parameters in Solaris 10 .............................................................. 154
Message queue and shared memory parameters on HP-UX ...............155
Kernel parameters on Linux ....................................................................157
Adjusting data buffer size (Windows) ............................................................157Other Windows issues .......................................................................................159
Appendix A Additional resources
Performance tuning information at vision online ...............................161
Performance monitoring utilities ...........................................................161
Freeware tools for bottleneck detection ................................................161
Mailing list resources ................................................................................162
Index 163
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Section I
Backup planning andconfiguration guidelines
Section I helps you lay the foundation of good backup performance through
planning and configuring your NetBackup installation. Section I also includes
some best practices.
Section I includes these chapters:
NetBackup Capacity Planning
Master Server Configuration Guidelines
Media Server Configuration Guidelines
Media Configuration Guidelines
Database Backup Guidelines
Best Practices
Note: For a discussion of tuning factors and general recommendations that may
be applied to an existing installation, see Section II.
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Chapter 1
NetBackup capacityplanning
This chapter explains how to design your backup system as a foundation for
good performance.
This chapter includes the following sections:
Introduction on page 13
Analyzing your backup requirements on page 14
Designing your backup system on page 16
Questionnaire for capacity planning on page 37
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12 NetBackup capacity planningNew
NewVeritas NetBackup is a high-performance data protection application. Its
architecture is designed for large and complex distributed computing
environments. NetBackup provides a scalable storage management server that
can be configured for network backup, recovery, archival, and file migration
services.
This manual is for administrators who want to analyze, evaluate, and tune
NetBackup performance. This manual is intended to answer questions such as
the following: How big should the backup server be? How can the NetBackup
server be tuned for maximum performance? How many CPUs and tape drives
are needed? How to configure backups to run as fast as possible? How to
improve recovery times? What tools can characterize or measure how
NetBackup is handling data?
Note: Most critical factors in performance are based in hardware rather than
software. Hardware selection and configuration have roughly four times theweight that software has in determining performance. Although this guide
provides some hardware configuration assistance, it is assumed for the most
part that your devices are correctly configured.
Disclaimer
It is assumed you are familiar with NetBackup and your applications, operating
systems, and hardware. The information in this manual is advisory only,
presented in the form of guidelines. Changes to an installation undertaken as a
result of the information contained herein should be verified in advance for
appropriateness and accuracy. Some of the information contained herein may
apply only to certain hardware or operating system architectures.
Note: The information in this manual is subject to change.
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13NetBackup capacity planningIntroduction
IntroductionThe first step toward accurately estimating your backup requirements is a
complete understanding of your environment. Many performance issues can be
traced to hardware or environmental issues. A basic understanding of the entire
backup data path is important in determining the maximum performance you
can expect from your installation.
Every backup environment has a bottleneck. It may be a fast bottleneck, but it
will determine the maximum performance obtainable with your system.
Example:
Consider the configuration illustrated below. In this environment, backups run
slowly (in other words, they are not completing in the scheduled backup
window). Total throughput is eight to 10 megabytes per second.
What makes the backups run slowly? How can NetBackup or the environment be
configured to increase backup performance in this situation?
Figure 1-1 Dedicated NetBackup server
The explanation is that the LAN, having a speed of 100megabits per second, hasa theoretical throughput of 12.5 megabytes per second. In practice, 100BaseT
throughput is unlikely to exceed 70% utilization. Therefore, the best delivered
data rate is about 8 megabytes per second to the NetBackup server. The
throughput can be even lower than this, when TCP/IP packet headers,
TCP-window size constraints, router hops (packet latency for ACK packets
delays the sending of the next data packet), host CPU utilization, filesystem
overhead, and other LAN users activity are considered. Since the LAN is the
slowest element in the backup path, it is the first place to look in order toincrease backup performance in this configuration.
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14 NetBackup capacity planningAnalyzing your backup requirements
Analyzing your backup requirementsMany elements influence your backup strategy. You must analyze and compare
these factors and then make backup decisions according to your sites priorities.
When you plan your installations NetBackup capacity, ask yourself the
following questions:
Which systems need to be backed up?
It is important that you identify all systems that need to be backed up and
then list each system separately so that you can identify any that require
more resources to back up. Document which machines have local tape
drives or libraries attached and be sure to write down the model type of
each tape drive or library. In addition, record each host name, operating
system and version, database type and version, network technology (for
example, ATM or 100BaseT), and location.
How much data will be backed up?
Calculate how much data you need to back up. Include the total disk space
on each individual system, including that for databases. Remember to addthe space on mirrored disks only once.
By calculating the total size for all disks, you can design a system that takes
future growth into account. You should also consider the future by
estimating how much data you will need to back up in six months to a few
years from now.
Do you plan to back up databases or raw partitions?
If you are planning to backing up databases, you need to identify thedatabase engines, their version numbers, and the method that you will
use to back them up. NetBackup can back up several database engines
and raw file systems, and databases can be backed up while they are
online or offline. To back up any database while it is online, you need a
NetBackup database agent for your particular database engine.
If you use NetBackup Advanced Client to back up databases using raw
partitions, you are actually backing up as much data as the total size of
your raw partition. Also, remember to add the size of your databasebackups to your final calculations when figuring out how much data
you need to back up.
Will you be backing up specialty servers like MS-Exchange, Lotus
Notes, etc.?
If you are planning on backing up any specialty servers, you will need
to identify their types and application release numbers. As previously
mentioned, you may need a special NetBackup agent to properly back
up your particular servers.
What types of backups are needed and how often should they take place?
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15NetBackup capacity planningAnalyzing your backup requirements
The frequency of your backups has a direct impact on your:
Tape requirements
Data transfer rate considerations
Restore opportunities.
To properly size your backup system, you must decide on the type and
frequency of your backups. Will you perform daily incremental and weekly
full backups? Monthly or bi-weekly full backups?
How much time is available to run each backup?
It is important to know the window of time that is available for each backup.
The length of a window dictates several aspects of your backup strategy, for
example, you may want a larger window of time to back up multiple,
high-capacity servers. Or you may consider the use of advanced NetBackup
features such as synthetic backups, a local snapshot method, or
FlashBackup.
How long should backups be retained?
An important factor while designing your backup strategy is to consideryour policy for backup expiration. The amount of time a backup is kept is
also known as the retention period. A fairly common policy is to expire
your incremental backups after one month and your full backups after six
months. With this policy, you can restore any daily file change from the
previous month and restore data from full backups for the previous six
months. The length of the retention period depends on your own unique
requirements and business needs, and perhaps regulatory requirements.
However, keep in mind that the length of your retention period has adirectly proportional effect on the number of tapes you will need and the
size of your NetBackup catalog database. Your NetBackup catalog database
keeps track of all the information on all your tapes. The catalog size is
tightly tied in to your retention period and the frequency of your backups.
Also, database management daemons and services may become bottlenecks.
If backups are sent off site, how long must they remain off site?
If you plan to send tapes to an off site location as a disaster recovery option,
you must identify which tapes to send off site and how long they remain off
site. You might decide to duplicate all your full backups, or only a select few.
You might also decide to duplicate certain systems and exclude others. As
tapes are sent off site, you will need to buy new tapes to replace them until
they are recycled back from off site storage. If you forget this simple detail,
you will run out of tapes when you most need them.
What is your network technology?
If you are planning on backing up any system over a network, note thenetwork types that you will be using. The next section, Designing your
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backup system, explains how to calculate the amount of data you can
transfer over those networks in a given time.Depending on the amount of data that you want to back up and the
frequency of those backups, you might want to consider installing a private
network just for backups.
What new systems will be added to your site in the next six months?
It is important to plan for future growth when designing your backup
system. By analyzing the potential future growth of your current or future
systems, you can insure the backup solution that you have accommodates
the kind of environment that you will have in the future. Remember to add
any resulting growth factor that you incur to your total backup solution.
Will user-directed backups or restores be allowed?
Allowing users to do their own backups and restores can reduce the time it
takes to initiate certain operations. However, user-directed operations can
also result in higher support costs and the loss of some flexibility.
User-directed operations can monopolize media and tape drives when you
most need them. They can also generate more support calls and trainingissues while the users become familiar with the new backup system. You
will need to decide whether allowing user access to some of your backup
systems functions is worth the potential costs.
Other factors to consider when planning your backup capacity include:
Data type: What are the types of data: text, graphics, database? How
compressible is the data? How many files are involved? Will the data be
encrypted? (Note that encrypted backups may run slower. See Encryptionon page 133 for more information.)
Data location: Is the data local or remote? What are the characteristics of
the storage subsystem? What is the exact data path? How busy is the
storage subsystem?
Change management: Because hardware and software infrastructure will
change over time, is it worth the cost to create an independent test-backup
environment to ensure your production environment will work with thechanged components?
Designing your backup systemFollowing an analysis of your backup requirements, you can begin designing
your backup system. Use the following subsections in the order shown below.
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Note: The ideas and examples that follow are based on standard and ideal
calculations. Your numbers will differ based on your particular environment,
data, and compression rates.
Calculate the required data transfer rate for your backups on page 17
Calculate how long it will take to back up to tape on page 18
Calculate how many tape drives are needed on page 20
Calculate the required data transfer rate for your network(s) on page 21
Calculate the size of your NetBackup catalog on page 22
Calculate the size of the EMM server on page 23
Calculate how much media is needed for full and incremental backups on
page 25
Calculate the size of the tape library needed to store your backups on
page 26 Design your master backup server based on your previous findings on
page 27
Estimate the number of master servers needed on page 29
Design your media server on page 31
Estimate the number of media servers needed on page 32
Design your NOM server on page 33
Summary on page 36
Calculate the required data transfer rate for your backupsThis is the rate of transfer your system must achieve to complete a backup of all
your data in the allowed time window. Use the following formula to calculate
your ideal data transfer rate for full and incremental backups:
Ideal data transfer rate = (Amount of data to back up) / (Backup window)
On average, the daily change in data for many systems is between 10 and 20
percent. Calculating a change of 20% in the (Amount of data to back up) and
dividing it by the (Backup window) will give you the backup data rate for
incremental backups.
If you are running cumulative-incremental backups, you need to take into
account which data is changing, since that affects the size of your backups. For
example, if the same 20% of the data is changing daily, your
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18 NetBackup capacity planningDesigning your backup system
cumulative-incremental backup will be much smaller than if a completely
different 20% changes every day.
Example: Calculating your ideal data transfer rate during the week
Assumptions:
Amount of data to back up during a full backup = 500 gigabytes
Amount of data to back up during an incremental backup = 20% of a full
backup Daily backup window = 8 hours
Solution 1:
Full backup = 500 gigabytes
Ideal data transfer rate = 500 gigabytes/8 hours = 62.5 gigabytes/hour
Solution 2:
Incremental backup = 100 gigabytes
Ideal data transfer rate = 100 gigabytes/8 hours = 12.5 gigabytes/hour
To calculate your ideal data transfer rate during the weekends, divide the
amount of data that needs to be backed up by the length of the weekend backup
window.
Calculate how long it will take to back up to tapeOnce you know what your ideal data transfer rates are for backups, you can
figure out what kind of tape drive technology will meet your needs. Because you
also know the length of your available backup windows and the amount of data
that needs to be backed up, you can also calculate how many tape drives you will
need.
The table below lists the transfer rates for several tape drive technologies. The
values listed are those published by their individual manufacturers and those
observed in real-life situations. Keep in mind that device manufacturers list
optimum rates for their devices. In reality, it is quite rare to achieve those values
when a system has to deal with the overhead of the operating system, CPU loads,
bus architecture, data types, and other hardware and software issues.
The typical gigabytes/hour values from the Table 1-1Tape drive data transferrates table represent a range of real-life transfer rates for several devices, with
and without compression. When you design your backup system, consider the
nature of both your data and your environment. It is generally wise to estimate
on the conservative side when planning capacity. For instance, use the low end
of the typical gigabytes/hour range for your planning unless you have specific
reasons to use the higher numbers.
To calculate the length of your backups using a particular tape drive, use the
formula:
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Actual data transfer rate = (Amount of data to back up)/((Number of drives)
* (Tape drive transfer rate))
Example: Calculating the actual data transfer rate required
Assumptions:
Amount of data to back up during a full backup = 500 gigabytes
Daily backup window = 8 hours
Ideal transfer rate (data/(backup window)) = 500 gigabytes/8 hours = 62.5
gigabytes/hour
Solution 1:Tape drive = 1 drive, LTO gen 1
Tape drive transfer rate = 37 gigabytes/hour
Actual data transfer rate = 500 gigabytes/((1 drive) * (37 gigabytes/hour)) =
13.51 hours
With a data transfer rate of 37 gigabytes/hour, a single LTO gen 1 tape drive will
take 13.51 hours to perform a 500 gigabyte backup. A single LTO gen 1 tape
drive will not be able to perform your backup in eight hours. You will need a
faster tape drive or another LTO gen 1 tape drive.
Solution 2:
Tape drive = 1 drive, LTO gen 2
Tape drive transfer rate = 75 gigabytes/hour
Backup length = 500 gigabytes/((1 drive) * (75 gigabytes/hour)) = 6.67 hours
With a data transfer rate of 75 gigabytes/hour, a single LTO gen 2 tape drive
will take 6.67 hours to perform a 500 gigabyte backup.
Table 1-1 Tape drive data transfer rates
Drive Theoretical
gigabytes/hour (nocompression)
Theoretical
gigabytes/hour (2:1compression)
Typical
gigabytes/hour
LTO gen 1 54 108 37-65
LTO gen 2 108 216 75-130
LTO gen 3 288 576 200-345
SDLT 320 57 115 40-70
SDLT 600 129 259 90-155
STK 9940B 108 252 (2.33:1) 75-100
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Depending on the several factors that can influence the transfer rates of your
tape drives, it is possible to obtain higher or lower transfer rates. The solutionsin the examples above are approximations of what you can expect.
Note also that a backup of encrypted data may take more time. See Encryption
on page 133 for more information.
Calculate how many tape drives are neededTo calculate how many tape drives you will need to perform your backups, use
the formula below and the typical gigabytes/hour transfer rates from the tableTape drive data transfer rates on page 19.
Number of drives = (Amount of data to back up) /((Backup window) * (Tape
drive transfer rate))
Example: Calculating the number of tape drives needed to perform abackup
Assumptions:
Amount of data to back up = 500 gigabytesBackup window = 8 hours
Solution 1:
Tape drive type = SDLT 320
Tape drive transfer rate = 40 gigabytes/hour
Number of drives = 500 gigabytes/ ((8 hours) * (40 gigabytes/hour)) = 1.56 =
2 drives
Solution 2:Tape drive type = SDLT 600
Tape drive transfer rate = 90 gigabytes/hour
Number of drives = 500 gigabytes/((8 hours) * (90 gigabytes/hour)) = 0.69 =
1 drive
Although it is quite straightforward to calculate the number of drives needed to
perform a backup, it is difficult to spread the data streams evenly across all
drives. To effectively spread your data, you have to experiment with various
backup schedules, NetBackup policies, and your hardware configuration. See
Basic tuning suggestions for the data path on page 91 to determine your
options.
Another important aspect of calculating how many tape devices you will need is
calculating how many tape devices you can attach to a drive controller.
When calculating the maximum number of tape drives that you can attach to a
controller, you must know the drive and controller maximum transfer rates as
published by their manufacturers. Failure to use maximum transfer rates foryour calculations can result in saturated controllers and unpredictable results.
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The table below displays the transfer rates for several drive controllers. In
practice, your transfer rates might be slower because of the inherent overheadof several variables including your file system layout, system CPU load, and
memory usage.
Calculate the required data transfer rate for your network(s)When designing your backup system to perform backups over a network, you
need to move data from your client(s) to your backup server(s) at a fast enough
rate to finish your backups within your allotted backup window. Using the
typical gigabytes/hour transfer rates from the table below, you can find out the
typical transfer rates of some fairly common network technologies. To calculate
the required data transfer rate, use the formula below:
Required network data transfer rate = (Amount of data to back up) / (Backup
window)
Table 1-2 Drive controller data transfer rates
Drive Controller Theoreticalmegabytes/second
Theoreticalgigabytes/hour
ATA-5 (ATA/ATAPI-5) 66 237.6
Wide Ultra 2 SCSI 80 288
iSCSI 100 360
1 Gigabit Fibre Channel 100 360
SATA/150 150 540
Ultra-3 SCSI 160 576
2 Gigabit Fibre Channel 200 720
SATA/300 300 1080
Ultra320 SCSI 320 1152
4 Gigabit Fibre Channel 400 1440
Table 1-3 Network data transfer rates
Network Technology Theoretical gigabytes/hour Typical gigabytes/hour
10BaseT (switched) 3.6 2.7
100BaseT (switched) 36 32
1000BaseT (switched) 360 320
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To calculate your NetBackup catalog size, you need to know how much data you
will be backing up for full and incremental backups, how often these backupswill be performed, and for how long they will be retained. Here are two simple
formulas to calculate these values:
Data being tracked = (Amount of data to back up) * (Number of backups) *
(Retention period)
NetBackup catalog size = 120 * (number of files)
Note: If you select NetBackups True Image Restore option, your catalog will be
twice as large as a catalog without this option selected. True Image Restore
collects the information required to restore directories to their contents at the
time of any selected full or incremental backup. Because the additional
information that NetBackup collects for incremental backups is the same as that
of a full backup, incremental backups take much more disk space when you
collect True Image Restore information.
Example: Calculating the size of your NetBackup catalogAssumptions:
Amount of data to back up = 100 gigabytes
Incremental backups = 20% of all data
Full backups per month = 4
Retention period for full backups = 6 months
Incremental backups per month = 30
Retention period for incremental backups = 1 month
Solution:
Size of full backups = 100 gigabytes * 4 * 6 months = 2.4 terabytes
Size of incremental backups = (20% of 100 gigabytes) * 30 * 1 month = 600
gigabytes
Total data tracked = 2.4 terabytes + 600 gigabytes = 3 terabytes
NetBackup catalog size = 2% of 3 terabytes= 60 gigabytes
Based on the previous assumptions, it will take 60 gigabytes of disk space to hold
the catalog. Compression can reduce the size of your catalog to one-sixth or lessof its uncompressed size. When the catalog is decompressed, this is only done
for the images and time period of the particular system that you need to restore.
Calculate the size of the EMM serverBy default, the EMM server resides on the NetBackup master server. The
amount of space needed for the EMM server is determined by the size of the
NetBackup database (NBDB), as explained below.
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Note: This space must be included when determining size requirements for a
master or media server, depending on where the EMM server is installed.
Space for the NBDB on the EMM server is required in the following two
locations:
UNIX
/usr/openv/db/data
/usr/openv/db/staging
Windows
install_path\NetBackupDB\datainstall_path\NetBackupDB\staging
Calculate the required space for the NBDB in each of the two directories, as
follows:
60 MB + (2 KB * number of volumes configured for EMM)
where EMMis the Enterprise Media Manager, and volumes are NetBackup
(EMM) media volumes. Note that 60 MB is the default amount of space needed
for the NBDB database used by the EMM server. It includes pre-allocated spacefor configuration information for devices and storage units.
Note: During NetBackup installation, the install script looks for 60 MB of free
space in the above /data directory; if there is insufficient space, the installation
fails. The space in /staging is only required when a hot catalog backup is run.
Example: Calculating the space needed for the EMM serverAssuming there are 1000 EMM volumes to back up, the total space needed for
the EMM server in /usr/openv/db/data is:
60 MB + (2 KB * 1000 volumes) = 62 MB
The same amount of space is required in /usr/openv/db/staging. The
amount of space required may grow over time as the NBDB database increases in
size.
Note: The above 60 MB of space is pre-allocated, and is derived from the
following separate databases that are consolidated into the EMM database in
NetBackup 6.0: globDB, ltidevs, robotic_def, namespace.chksum, ruleDB,
poolDB, volDB, mediaDB, storage_units, stunit_groups, SSOhosts, and media
errors database. See the NetBackup Release Notes, in the section titled
Enterprise Media Manager Databases, for additional details on files and
database information included in the EMM database.
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25NetBackup capacity planningDesigning your backup system
Calculate how much media is needed for full and incremental
backupsAs part of planning your backup strategy, calculate how many tapes will be
needed to store and retrieve your backups. The number of tapes that you will
need depends on:
The amount of data that you are backing up
The frequency of your backups
The planned retention periods The capacity of the media used to store your backups.
If you expect your site's workload to increase over time, you can ease the pain of
future upgrades by planning for expansion. Design your initial backup
architecture so it can evolve to support more clients and servers. Invest in the
faster, higher-capacity components that will serve your needs beyond the
present.
A simple formula for calculating your tape needs is shown here:Number of tapes = (Amount of data to back up) / (Tape capacity)
To calculate how many tapes will be needed based on all your requirements, the
above formula can be expanded to
Number of tapes = ((Amount of data to back up) * (Frequency of backups) *
(Retention period)) / (Tape capacity)
Example: Calculating how many tapes are needed to store all yourbackups
Preliminary calculations:
Size of full backups = 500 gigabytes * 4 (per month) * 6 months = 12terabytes
Table 1-4 Tape capacities
Drive Theoretical gigabytes
(no compression)
Theoretical gigabytes
(2:1 compression)
LTO gen 1 100 200
LTO gen 2 200 400
LTO gen 3 400 800
SDLT 320 160 320
SDLT 600 300 600
STK 9940B 200 400
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26 NetBackup capacity planningDesigning your backup system
Size of incremental backups = (20% of 500 gigabytes) * 30 * 1 month = 3
terabytesTotal data tracked = 12 terabytes + 3 terabytes = 15 terabytes
Solution 1:
Tape drive type = LTO gen 1
Tape capacity without compression = 100 gigabytes
Tape capacity with compression = 200 gigabytes
Without compression:
Tapes needed for full backups = 12 terabytes/100 gigabytes = 120
Tapes needed for incremental backups = 3 terabytes/100 gigabytes = 30Total tapes needed = 120 + 30 = 150 tapes
With 2:1 compression:
Tapes needed for full backups = 12 terabytes/200 gigabytes = 60
Tapes needed for incremental backups = 3 terabytes/200 gigabytes = 15
Total tapes needed = 60 + 15 = 75 tapes
Solution 2:
Tape drive type = LTO gen 3Tape capacity without compression = 400 gigabytes
Tape capacity with compression = 800 gigabytes
Without compression:
Tapes needed for full backups = 12 terabytes/400 gigabytes = 30
Tapes needed for incremental backups = 3 terabytes/400 gigabytes = 7.5 ~=
8
Total tapes needed = 30 + 8 = 38 tapes
With 2:1 compression:Tapes needed for full backups = 12 terabytes/800 gigabytes = 15
Tapes needed for incremental backups = 3 terabytes/800 gigabytes = 3.75
~= 4
Total tapes needed = 15 + 4 = 19 tapes
Calculate the size of the tape library needed to store your backups
To calculate how many robotic library tape slots are needed to store all yourbackups, take the number of tapes for backup calculated in Calculate how much
media is needed for full and incremental backups on page 25 and add tapes for
catalog backup and cleaning:
Tape slots needed = (Number of tapes needed for backups) + (Number of
tapes needed for catalog backups) + 1 (for a cleaning tape)
A typical example of tapes needed for catalog backup is 2.
Additional tapes may be needed for the following:
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27NetBackup capacity planningDesigning your backup system
If you plan to duplicate tapes or to reserve some media for special
(non-backup) use, add those tapes to the above formula. Add tapes needed for future data growth. Make sure your system has a
viable upgrade path as new tape drives become available.
Design your master backup server based on your previous findingsTo design and configure a master backup server, you must:
Perform an initial backup requirements analysis, as outlined in the section
Analyzing your backup requirements on page 14.
Perform the calculations outlined in the previous steps of the current
section.
Designing a backup server becomes a simple task once the basic design
constraints are known:
Amount of data to back up
Size of the NetBackup catalog
Number of tape drives needed
Number of networks needed
Given the above, a simple approach to designing your backup server can be
outlined as follows:
Acquire a dedicated server
Add tape drives and controllers (for saving your backups)
Add disk drives and controllers (for OS and NetBackup catalog)
Add network cards
Add memory
Add CPUs
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p p y p gDesigning your backup system
Figure 1-2 Backup server hardware component
In some cases, it may not be practical to design a generic server to back up all ofyour systems. You might have one or several large servers that cannot be backed
up over a network within your backup window. In such cases, it is best to back up
those servers using their own locally-attached tape drives. Although this section
discusses how to design a master backup server, you can still use its information
to properly add the necessary tape drives and components to your other servers.
The next example shows how to configure a master server using the design
elements gathered from the previous sections.
Example: Designing your master backup server
Assumptions:
Amount of data to back up during full backups = 500 gigabytes
Amount of data to back up during incremental backups = 100 gigabytes
Tape drive type = SDLT 600
Tape drives needed = 1
Network technology = 100BaseTNetwork cards needed = 1
Size of NetBackup catalog after 6 months = 60 gigabytes (from Example:
Calculating the size of your NetBackup catalog on page 23)
Solution (the following values are based on the table CPUs needed per
master/media server component and Memory needed per master/media
server component on page 32):
CPUs needed for network cards = 1
CPUs needed for tape drives = 1
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Designing your backup system
CPUs needed for OS = 1
Total CPUs needed = 1 + 1 + 1 = 3
Memory needed for network cards = 16 megabytes
Memory needed for tape drives = 128 megabytes
Memory needed for OS and NetBackup = 1 gigabyte
Total memory needed = 16 + 128 + 1000 = 1.144 gigabytes
Based on the above, your master server needs 3 CPUs and 1.144 gigabytes of
memory. In addition, you need 60 gigabytes of disk space to store your
NetBackup catalog, along with the necessary disks and drive controllers to
install your operating system and NetBackup (2 gigabytes should be ample formost installations). This server also requires one SCSI card, or another, faster,
adapter for use with the tape drive (and robot arm) and a single 100BaseT card
for network backups.
When designing your backup server solution, begin with a dedicated server for
optimum performance. In addition, consult with your servers hardware
manufacturer to ensure that the server can handle your other components. In
most cases, servers have specific restrictions on the number and mixture of
hardware components that can be supported concurrently. Overlooking this last
detail can cripple even the best of plans.
Estimate the number of master servers neededOne of the key elements in designing your backup solution is estimating how
many master servers are needed. As a rule, the number of master servers is
proportional to the number of media servers. To determine how many master
servers are required, consider the following:
The master server must be able to periodically communicate with all its
media servers. If there are too many media servers, master server
processing may be overloaded.
Consider business-related requirements. For example, if an installation has
different applications which require different backup windows, a single
master may have to run backups continually, leaving no spare time for
catalog cleaning, catalog backup, or maintenance.
If at all possible, design your configuration with one master server per
firewall domain. In addition, do not share robotic tape libraries between
firewall domains.
As a rule, the number of clients (separate physical hosts) per master server
is not a critical factor for NetBackup. Ordinary backup processing
performed by each client has little or no impact on the NetBackup server,
unless, for instance, the clients all have database extensions or are trying torun ALL_LOCAL_DRIVES at the same time.
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Designing your backup system
Plan your configuration so that it contains no single point of failure.
Provide sufficient redundancy to ensure high availability of the backup
process. Having more tape drives or media may reduce the number of media
servers needed per master server.
Consider limiting the number of media servers handled by a master to the
lower end of the estimates in the following table, Table 1-5Number of media
servers supported by a master server.
Although a well-managed NetBackup environment can handle more media
servers than the numbers listed in this table, you may find your backup
operations more efficient and manageable with fewer but larger mediaservers. The variation in the number of media servers per master server for
each scenario in the table depends on the number of jobs submitted,
multiplexing, multi-streaming, and network capacity.
For information on designing a master server, refer to Design your master
backup server based on your previous findings on page 27.
Note: This table provides a rough estimate only, as a guideline for initialplanning. Note also that the RAM amounts shown below are for a base
NetBackup installation; RAM requirements vary depending on the NetBackup
features, options, and agents being used.
Table 1-5 Number of media servers supported by a master server
Master
Server Type
RAM Number of
Processors
Master
Backups
Media Server
Backups
Media
Configuration
Number of
MediaServers PerMaster
Server
Solaris 2 gigabytes 4 Not backing
up clients
Media server
backing up
itself only
10 - 20 tape
drives in not
more than 2
libraries
25 - 40
Solaris 4 gigabytes 4 Not backing
up clients
Media server
backing up
itself only
10 - 20 tape
drives in not
more than 2
libraries
35 - 50
Solaris 8+ gigabytes 4 Not backing
up clients
Media server
backing up
network
clients
20 - 40 tape
drives in not
more than 2
libraries
50 -70
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Designing your backup system
Design your media serverYou can use a media server not only to back up itself, but also to back up other
systems and reduce or balance the load on your master server. With NetBackup,
the robotic control of a library can be on either the master server or the media
server.
Windows 2 gigabytes 4 Not backing
up clients
Media server
backing up
itself only
15 - 30 tape
drives in not
more than 2
libraries
10+
Windows 4 gigabytes 4 Not backing
up clients
Media server
backing up
itself only
20 - 40 tape
drives in not
more than 2
libraries
20+
Windows 8+ gigabytes 4 Not backing
up clients
Media server
backing up
networkclients
40 - 128 tape
drives in not
more than 2libraries
50+
Table 1-5 Number of media servers supported by a master server
MasterServer Type
RAM Number ofProcessors
MasterBackups
Media ServerBackups
MediaConfiguration
Number ofMedia
Servers PerMaster
Server
Table 1-6 CPUs needed per master/media server component
Component How many and what kind of component Number of CPUs per
component
Network cards 2-3 100BaseT cards 1
5-7 10BaseT cards 1
1 ATM card 1
1-2 Gigabit Ethernet cards with coprocessor 1
Tape drives 2 LTO gen 3 drives 1
2-3 SDLT 600 drives 1
2-3 LTO gen 2 drives 1
3-4 LTO gen 1 drives 1
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Designing your backup system
The information in the above tables is a rough estimate only, intended as a
guideline for initial planning.
In addition to the above media server components, you must also add the
necessary disk drives to store the NetBackup catalog and your operating system.The size of the disks needed to store your catalog depends on the calculations
explained earlier under Calculate the size of your NetBackup catalog on
page 22.
Estimate the number of media servers neededHere are some guidelines for estimating the number of media servers needed:
I/O performance is generally more important than CPU performance.
Consider CPU, I/O, and memory expandability when choosing a server.
Consider how many CPUs are needed (see CPUs needed per master/media
server component on page 31). Here are some general guidelines:
Experiments (with Sun Microsystems) have shown that a useful,
conservative estimate is 5MHz of CPU capacity per 1MB/second of data
movement in and out of the NetBackup media server. Keep in mind that the
operating system and other applications also use the CPU. This estimate is
for the power available to NetBackup itself.
OS and NetBackup 1
Table 1-6 CPUs needed per master/media server component
Component How many and what kind of component Number of CPUs percomponent
Table 1-7 Memory needed per master/media server component
Component Type of component Memory per component
Network cards 16 megabytes
Tape drives LTO gen 3 drive 256 megabytes
SDLT 600 drive 128 megabytes
LTO gen 2 drive 128 megabytes
LTO gen 1 drive 64 megabytes
OS and NetBackup 1 gigabyte
OS, NetBackup, and NOM 1 or more gigabytes
NetBackup multiplexing 8 megabytes * (# streams) * (# drives)
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Designing your backup system
Example:
A system backing up clients over the network to a local tape drive at the
rate of 10MB/second would need 100MHz of available CPU power:
50MHz to move data from the network to the NetBackup server
50MHz to move data from the NetBackup server to tape.
Consider how much memory is needed (see Memory needed per
master/media server component on page 32).
At least 512 megabytes of RAM is recommended if the server is running a
Java GUI. NetBackup uses shared memory for local backups. NetBackup
buffer usage will affect how much memory is needed. See the Tuning theNetBackup data transfer path chapter for more information on NetBackup
buffers.
Keep in mind that non-NetBackup processes need memory in addition to
what NetBackup needs.
A media server moves data from disk (on relevant clients) to storage
(usually disk or tape). The server must be carefully sized to maximize
throughput. Maximum throughput is attained when the server keeps its
tape devices streaming. (For an explanation of streaming, see Tape
streaming on page 126.)
Media server factors to consider for sizing include:
Disk storage access time
Adapter (for example, SCSI) speed
Bus (for example, PCI) speed
Tape device speed Network interface (for example, 100BaseT) speed
Amount of system RAM
Other applications, if the host is non-dedicated
The platform chosen must be able to drive all network interfaces and keep all
tape devices streaming.
Design your NOM serverBefore setting up a NetBackup Operations Manager (NOM) server, review the
recommendations and requirements listed in the installation chapter of the
NetBackup Operations Manager Getting Started Guide. Note, for example:
NOM server software does not have to be installed on the same server as
NetBackup 6.0 master server software. Since the NOM server is also a web
server, installing NOM on a master server may impact security and
performance. (The guidelines provided here assume that the NOM server is
a standalone host not acting as a master server.)
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Symantec recommends that you not install NOM software on a clustered
NetBackup master server.
Sizing considerations
The size of your NOM server depends largely on the number of NetBackup
objects that NOM manages. See the following table.
Based on the above factors, the following NOM server components should be
sized accordingly.
The next section describes the NOM database and how it affects disk space
requirements, followed by overall sizing guidelines for NOM.
NOM database
The Sybase database used by NOM is similar to that used by NetBackup and isinstalled as part of the NOM server installation.
The disk space needed for the initial installation of NOM depends on the
volume of data initially loaded onto the server, based on the following:
number of policy data records, number of job data records, number of media
data records, and number of catalog image records.
The rate of NOM database growth depends on the quantity of data being
managed: policy data, job data, media data, and catalog data.
Factors in determining NOM server size
Number of master servers to manage(the number of media servers is irrelevant)
Number of policies
Number of jobs run per day
Number of media
Number of catalog images
NOM server components
Disk space (installed NOM binary + NOM database, described below)
Type and number of CPUs
RAM
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Sizing guidelines
The following guidelines are presented in groups based on the number of objectsthat your NOM server manages.
It is assumed that your NOM server is a standalone host (the host is not acting as
a NetBackup master server).
Note: Symantec recommends multiple NOM servers for deployments larger than
those described in the following guidelines.
Note: The guidelines are intended for basic planning purposes, and do not
represent fixed recommendations or restrictions.
In the following table, find the installation category that matches your site,
based on number of master servers that your NOM server will manage, number
of jobs per day, and so forth. Then consult the following table for NOM sizing
guidelines.
Using the NetBackup installation category from above (A, B, C, D), read across to
the recommended NOM server capacities.
Table 1-8 NOM sizing guidelines
NetBackup
installation
category
Master
servers
Jobs per
day
Policies Alerts per
day
Media
A 1 - 3 200 - 500 200 - 300 100 - 200 5000
B 3 - 5 500 - 1000 300 - 500 200 - 300 10000
C 5 - 7 1000 - 5000 1000 - 4000 500 - 800 20000
D 8 - 10 5000 - 8000 4000 - 8000 800 - 3000 30000
Table 1-9 NOM server capacities
NetBackup
installation
category
OS CPU type Number
of CPUs
RAM Disk
space
A Windows Pentium V 2 2 GB 80 GB
Solaris Sun Sparc 1200 MHz 1 2 GB 80 GB
B Windows Pentium V 2 2 GB 80 GB
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SummaryUsing the guidelines provided in this chapter, design a solution that can do a full
backup and incremental backups of your largest system within your time
window. The remainder of the backups can happen over successive days.Eventually, your site may outgrow its initial backup solution. By following these
guidelines, you can add more capacity at a future date without having to
redesign your basic strategy. With proper design and planning, you can create a
backup strategy that will grow with your environment.
As outlined in the previous sections, the number and location of the backup
devices are dependent on a number of factors.
The amount of data on the target systems, The available backup and restore windows,
The available network bandwidth, and
The speed of the backup devices.
If one drive causes backup window time conflicts, another can be added,
providing an aggregate rate of two drives. The trade-off is that the second drive
imposes extra CPU, memory, and I/O loads on the media server.
If you find that you cannot complete backups in the allocated window, one
approach is to either increase your backup window or decrease the frequency of
your full and incremental backups.
Another approach is to reconfigure your site to speed up overall backup
performance. Before you make any such change, you should understand what
determines your current backup performance. List or diagram your site network
and systems configuration. Note the maximum data transfer rates for all the
components of your backup configuration and compare these against the rateyou must meet for your backup window. This will identify the slowest
Solaris Sun Sparc 1200 MHz 1 2 GB 80 GB
C Windows Pentium V 4 4 GB 80 GB
Solaris Sun Sparc 1050 MHz 2 4 GB 80 GB
D Windows Pentium V 4 4 GB 80 GB
Solaris Sun Sparc 1050 MHz 2 8 GB 80 GB
Table 1-9 NOM server capacities
NetBackupinstallation
category
OS CPU type Numberof CPUs
RAM Diskspace
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components and, consequently, the cause of your bottlenecks. Some likely areas
for bottlenecks include the networks, tape drives, client OS load, and filesystem
fragmentation.
Questionnaire for capacity planningUse the following questionnaire to fill in information about the characteristics
of your systems and how they will be used. This data can help determine your
NetBackup client configurations and backup requirements.
Table 1-10 Backup questionnaire
Question Explanation
System name Any unique name to identify the machine. Hostname or any unique name for each
system.
Vendor The hardware vendor who made the system (for example, Sun, HP, IBM, generic PC)
Model For example: Sun E450, HP K580, Pentium II 300MHZ, HP Proliant 8500
OS version For example: Solaris 9, HP-UX 11i, Windows 2000 DataCenter
Building / location Identify physical location by room, building, and/or campus.
Total storage Total available internal and external storage capacity.
Used storage Total used internal and external storage capacity - if the amount of data to be backed up
is substantially different from the amount used, please note that.
Type of external array For example: Hitachi, EMC, EMC CLARiiON, STK.
Network connection For example, 10/100MB, Gigabit, T1. It is important to know if the LAN is a switched
network or not.
Database (DB) For example, Oracle 8.1.6, SQLServer 7.
Hot backup required? If so, this requires the optional database agent if backing up a database.
Key application For example: Exchange server, accounting system, software developer's code repository,
NetBackup critical policies.
Backup window For example: incrementals run M-F from 11PM to 6AM, Fulls are all day Sunday. This
information helps determine where potential bottlenecks will be and how to configure a
solution.
Retention policy For example: incrementals for 2 weeks, full backups for 13 weeks. This information will
help determine how to size the number of slots needed in a library.
Existing backup media Type of media currently used for backups.
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Comments? Any special situations to be aware of? Any significant patches on the operating system?
Will the backups be over a WAN? Do the backups need to go through a firewall?
Table 1-10 Backup questionnaire (continued)
Question Explanation
Chapter 2
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Chapter 2
Master Server
configuration guidelines
This chapter provides guidelines and recommendations for better performance
on the NetBackup master server.
This chapter includes the following sections: Managing NetBackup job scheduling on page 40
Miscellaneous considerations on page 44
Merging/splitting/moving servers on page 48
Guidelines for policies on page 49
Managing logs on page 50
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Managing NetBackup job schedulingThis section discusses issues related to NetBackup job scheduling.
Delays in starting jobsThe NetBackup Policy Execution Manager (nbpem) may not begin a backup at
exactly the time a backup policy's schedule window opens. This can happen
when you define a schedule or modify an existing schedule with a window start
time close to the current time.
For instance, suppose you create a schedule at 5:50 PM, specifying that backups
should start at 6:00 PM. You complete the policy definition at 5:55 PM. At 6:00
PM, you expect to see a backup job for the policy start, but it does not. Instead,
the job takes another several minutes to start.
The explanation is that NetBackup receives and queues policy change events as
they happen, but processes them periodically as configured in the Policy Update
Interval setting under Host Properties > Master Server > Properties > Global
Settings (the default is 10 minutes). The backup does not start until the firsttime NetBackup processes policy changes after the policy definition is
completed at 5:55 PM. NetBackup may not process the changes until 6:05 PM.
For each policy change, NetBackup determines what needs to be done and
updates its work list accordingly.
Delays in running queued jobs
If jobs remain in the queue and only one job runs at a time, make sure thefollowing attributes are set to allow jobs to run simultaneously:
Host Properties > Master Server > Properties > Global Attributes >
Maximumjobs per client (should be greater than 1).
Host Properties > Master Server > Properties > Client Attributes setting
for Maximum data streams (should be greater than 1).
Policy attribute Limit jobs per policy (should be greater than 1).
Policy schedule attribute Media multiplexing (should be greater than 1).
Check the storage unit properties:
Is the storage unit enabled to use multiple drives (Maximum concurrent
write drives)? If you want to increase this value, remember to set it to
fewer than the number of drives available to this storage unit.
Otherwise, restores and other non-backup activities will not be able to
run while backups to the storage unit are running.
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Is the storage unit enabled for multiplexing (Maximum streams per
drive)? You can write a maximum of 32 jobs to one tape at the same
time.
Job delays caused by unavailable mediaIf the media in a storage unit are not configured or are unusable (such as being
expired, or the maximum mounts setting was exceeded, or the wrong pool was
selected), the job will fail if no other storage units are usable. If media are
unavailable, new media will have to be added, or the media configuration will
have to be changed to make media available (such as changing the volume pool
or the maximum mounts).
If the media in a storage unit are usable but are currently busy, the job will be
queued. The NetBackup Activity Monitor should display the reason for the job
queuing, such as media are in use. If the media are in use, the media will
eventually stop being used and the job will run.
Delays after removing a media serverA job may be queued by the NetBackup Job Manager (nbjm) if the media server is
not available. This is not because of communication time-outs, but because EMM
knows the media server is down and the NetBackup Resource Broker (nbrb)
queues the request to be retried later.
If a media server is configured in EMM but has been physically removed,
powered off, or disconnected from the network, or if the network is down for any
reason, the media and device selection logic of EMM will queue the job if noother media servers are available. The Activity Monitor should display the
reason for the job queuing, such as media server is offline. Once the media
server is online again in EMM, the job will start. In the meantime, if other media
servers are available, the job will run on another media server.
If a media server is not configured in EMM (removed from the configuration),
regardless of the physical state of the media server, EMM will not select that
media server for use. If no other media servers are available, the job will fail.
Limiting factors for job schedulingFor every backup submitted, there may be one bprd process for the duration of
the job. When many requests are submitted to NetBackup simultaneously,
NetBackup will increase its use of memory and may eventually impact the
overall performance of the system. This type of performance degradation is
associated with the way a given operating system handles memory requests. It
may affect the functioning of all applications running on the system in question,
not just NetBackup.
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Note: The Activity Monitor may not update if there are many (thousands of) jobs
to view. If this happens, you may need to change the memory setting using theNetBackup Java command jnbSA with the -mx option. Refer to the
INITIAL_MEMORY, MAX_MEMORY subsection in the NetBackup System
Administrators Guide for UNIX and Linux, Volume I. Note thatthis situation
does not affect NetBackup's ability to continue running jobs.
Adjusting the servers network connection optionsWhen running many simultaneous jobs, the CPU utilization of the master server
may become very high. To reduce utilization and improve performance, adjust
the network connection options for the local machine on the Host Properties >
Master Server > Master Server Properties > Firewall display in the NetBackup
Administration Console (shown below), or you can add the following bp.conf
entry to the UNIX master server.
CONNECT_OPTIONS = localhost 1 0 2
For an explanation of the CONNECT_OPTIONS values, refer to the NetBackupSystem Administrators Guide for UNIX and Linux, Volume II.
The NetBackup Troubleshooting Guidealso provides information on network
connectivity issues.
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Using NOM to monitor jobs
The NetBackup Operations Manager (NOM) can be used to monitor theperformance of NetBackup jobs. NOM can also manage and monitor dozens
of NetBackup installations spread across multiple locations. Some of the
features provided by NOM are the following:
Web-based interface for efficient, remote administration across multiple
NetBackup servers from a single, centralized console.
Policy-based alert notification, using predefined alert conditions to specify
typical issues or thresholds within NetBackup. Flexible reporting, on issues such as backup performance, media utilization,
and rates of job success.
Consolidated job and job policy views per server (or group of servers), for
filtering and sorting job activity.
For more information on the capabilities of NOM, refer to the NOM online help
in the Administration console, or see the NetBackup Operations Manager Getting
Started Guide.
Disaster recovery testing and job schedulingThe following techniques may help in your disaster recovery testing.
Prevent the expiration of empty media.
a Go to the following directory:
UNIXcd /usr/openv/netbackup/bin
Windows
install_path\NetBackup\bin
b Enter the following:
mkdir bpsched.dcd bpsched.d
echo 0 > CHECK_EXPIRED_MEDIA_INTERVAL
Prevent the expiration of images
a Go to the following directory:
UNIX
cd /usr/openv/netbackup
Windows
cd install_path\NetBackup
b Enter the following:
UNIX
touch NOexpire
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Windows
echo 0 > NOexpire
Prevent backups from starting by shutting down bprd (NetBackup Request
Manager). This will suspend scheduling of new jobs by nbpem. To shut
down bprd, you can use the Activity Monitor in the NetBackup
Administration Console.
Restart bprd to resume scheduling.
Miscellaneous considerationsConsider the following issues when planning for or troubleshooting NetBackup.
Processing of storage unitsNetBackup storage units are processed in alphabetical order. You can affect how
storage units are selected and therefore when media servers are used by being
aware of the alphabetical order of the name of each storage unit. You can also
have some control over load balancing by using storage unit groups.
Storage unit groups contain a list of storage units that are available for that
policy to use. A storage unit group can be configured to use storage units in any
of three ways, in the New Storage Unit Group dialog of the NetBackup
Administration Console.
Use storage units in the order in which they are listed in the group.
Choose the least recently selected storage unit in the group.
Configure the storage unit group as a failover group. This means the first
storage unit in the group will be the only storage unit used. If the storage
unit is busy, then backups will queue. The second storage unit will only be
used if the first storage unit is down.
Disk staging
With disk staging, images can be created on disk initially, then copied later toanother media type (as determined in the disk staging schedule). The media type
for the final destination is typically tape, but could be disk. This two-stage
process leverages the advantages of disk-based backups in the near term, while
preserving the advantages of tape-based backups for long term.
Note that disk staging can be used to increase backup speed. For more
information, refer to the NetBackup System Administrators Guide, Volume I.
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File system capacity
There must be ample file system space for NetBackup to record its loggingand/or catalog entries on each master server, media server, and client. If logging
or catalog entries should exhaust available file system space, NetBackup will
cease to function. Having the ability to increase the size of the file system via
volume management is recommended. The disk containing the NetBackup
master catalog should be protected with mirroring or RAID hardware or
software technology.
NetBackup catalog strategiesThe NetBackup catalog resides on the disk of the NetBackup master server. The
catalog consists of the following parts:
Image database: The image database contains information about what has
been backed up. It is by far the largest part of the catalog.
NetBackup data stored in relational databases: This includes the media and
volume data describing media usage and volume information which is used
during the backups.
NetBackup configuration files: Policy, schedule and other flat files used by
NetBackup.
For more information on the catalog, refer to Catalog Maintenance and
Performance Optimization in the NetBackup Administrator's Guide Volume 1.
The NetBackup catalogs on the master server tend to grow large over time and
eventually fail to fit on a single tape. Here is the layout of the first few directory
levels of the NetBackup catalogs on the master server:
Figure 2-3 Directory layout on master Server
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Catalog backup typesIn addition to the existing cold catalog backups (which require that no jobs be
running), NetBackup 6.0 introduces online hot catalog backups. These hot
catalog backups can be performed while other jobs are running.
Note: For NetBackup release 6.0 and beyond, it is recommended that you use
schedule-based, incremental hot catalog backups with periodic full backups as
your preferred catalog backup method.
Guidelines for managing the catalog NetBackup catalog pathnames (cold catalog backups)
/vault
/failure_history
/Master/client_1
/Media_server /client_n
/class_template
NBDB.db
EMM_DATA.db
EMM_INDEX.db
NBDB.log
BMRDB.db
BMRDB.log
BMR_DATA.db
BMR_INDEX.db
vxdbms.conf
/usr/openv/
/db/data
/error/class
Image databaseelational databasefiles
server.conf
databases.conf
/var/global
Configuration files
/client
/config
/images
/Netbackup/db
License key and authenticationinformation/var /Netbackup/vault
/jobs
/media
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When defining the file list, use absolute pathnames for the locations of the
NetBackup and Media Manager catalog paths and include the server name
in the path. This is in case the media server performing the backup ischanged.
Back up the catalog using online, hot catalog backup
This type of catalog backup is for highly active NetBackup environments in
which continual backup activity is occurring. It is considered an online, hot
method because it can be performed while regular backup activity is taking
place. This type of catalog is policy-based and can span more than one tape.
It also allows for incremental backups, which can significantly reducecatalog backup times for large catalogs.
Store the catalog on a separate file system
The NetBackup catalog can grow quickly depending on backup frequency,
retention periods, and the number of files being backed up. If you store the
NetBackup catalog data on its own file system, this ensures that other disk
resources, root file systems, and the operating system are not impacted by
the catalog growth. For information on how to move the catalog, refer to
Catalog compression on page 48.
Change the location of the NetBackup relational database files
The location of the NetBackup relational database files can be changed
and/or split into multiple directories for better performance. For example,
by placing the transaction log file, NBDB.log, on a physically separate drive,
you gain better protection against disk failure and increased efficiency in
writing to the log file. Refer to the procedure in the section Moving NBDB
Database Files After Installation in the NetBackup Relational Databaseappendix of the NetBackup System Administrators Guide, Volume I.
Delay to compress catalog
The default value for this parameter is 0, which means that NetBackup does
not compress the catalog. As your catalog increases in size, you may want to
use a value between 10 and 30 days for this parameter. When you restore
old backups, which requires looking at catalog files that have been
compressed, NetBackup automatically uncompresses the files as needed,with minimal performance impact. For information on how to compress the
catalog, refer to Catalog compression on page 48.
Catalog backup not finishing in the available windowIf your cold catalog backups are not finishing in the backup window, or hot
catalog backups are running a long time, here are some possible solutions:
Use catalog archiving. Catalog archiving reduces the size of online catalogdata by relocating the large catalog .f files to secondary storage. NetBackup
48 Master Server configuration guidelinesMergin
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