3103047 16 Storage Area Networks

7/31/2019 3103047 16 Storage Area Networks

1/16

ESX Server System Management IIModule 6

Storage Area NetworksSAN Concepts

Hardware Compatibility

Configuration for ESX Server

SAN Failover


2/16

2

For ESX Server 2.0.1 2003-11-05Copyright 2003 VMware, Inc. All rights reserved.

2

Storage Area Networks, Network-Attached Storage

Host Host

Fileserver

NFS or SMB IP LAN or WAN links

SCSI Fibre Channel copper or fiber media

Diskarray +

intelligentcontroller

SAN NAS

Host Host


3/16

3


3

ESX Server, SAN, and NAS

VMkernel cannot use virtual disks on NAS Because VMkernel does not know NFS or SMB

NAS can be used for /vmimages -type storage Dont forget to export virtual disks!

VMkernel can use virtual disks on a SAN VM storage is centralized for easy management

Required for clustering between VMs on different ESX Servers

VMkernel can also use raw LUNs on a SAN Required for physical-to-virtual clustering


4/16

4


4

Parts of Fibre Channel SAN

Host Bus Adapter (HBA) This card connects the server to the FC network

Disk Array with Intelligent Controller(s) Supports the creation of volumes at various RAID levels

Controllers are often called storage ports or storageprocessors (SPs)

SAN Switches

Intelligent devices that interconnect HBAs and SPs Other devices

Tape drives, jukeboxes may also be connected to a SAN switch


5/16

5


5

SAN Topology: Direct

Server

HBA

Storage

SP

Low cost

No expansion without systemshutdown

No redundancy; many single points

of failure


6/16

6


6

SAN Topology: Trivial Fabric

Server

HBA

FC Switch

Storage

SP

Switch allows for later connectionof more storage or more servers(robust topology)

No redundancy; many single pointsof failure


7/167


7

SAN Topology: Arbitrated Loop (FCAL)

Splits transmit and receive into twophysical connections

Similar to a Token Ring dataconfiguration

Not supported by ESX Server

Server

HBA

Server

HBA

Storage

SP


8/168


8

SAN Topology: Fabric with Multipath

FC Switch

Server

HBA HBA

Server

HBA HBA

StorageSP SP


9/169


9

SAN Concepts

SAN devices are identified by a World Wide Number

Unique, 64-bit address assigned to each piece of Fibre Channelequipment: 210000e08b05672d

A LUN (logical unit number) Identifies individual units of storage behind a SCSI target ID: a RAID

group or a single disk drive Switched fabric SANs are partitioned into zones

Member devices cannot communicate across zone boundaries

Zoning is implemented in terms of switch ports (hard) or WWN (soft)


10/1610


10

ESX SAN Hardware Compatibility

HBAs: QLogic 2200, 2300 series (including OEMed HP cards)

Emulex 8000, 9000 series

Switches: Brocade Silkworm, others

Storage: IBM FAStT, ESS (Shark); HP MSA, EVA; EMC Symmetrix

Fujitsu-Siemens S60; HP XP; Hitachi(clustering configurations not yet supported)

EMC Clariion(failover and clustering configurations not yet supported)

Work closely with pre-sales or support!


11/1611


11

Key ESX Server configuration checks

Because LUNs may be discontiguous Ensure that DiskSupportSparseLUN is 1

Because VMkernel by default only scans LUNs

up to 7 Set DiskMaxLUN to desired maximum

Caution: large values will slow boot markedly

Use DiskMaskLUNs to control LUN visibilityvmhba0:0:4,6-255;

Because masking overridesmax LUN


12/1612


12

SAN Configuration Tips

Set DiskRetryUnitAttention to 1 if connecting to IBM FAStT On FAStT storage, unit attention signals can be noncritical

Some HBAs require further configuration Example: QLogic cards:

If IBM storage:Set Port Down Retry Count to 8If clustering:

Set Enable Target Reset to YesSet Full LIP Login to YesSet Full LIP Reset to No

Check the release notes!


13/1613


13

Making SAN storage available to VMs

Scan for new LUNs with MUI or command linevmkfstools s vmhba0

No need to reboot or shut down VMs

When rescanning QLogic adapters from command line, youmust first clear the cards cache of LUNsecho scsi-qlascan > /proc/scsi/qla2 ?00/ number

Allocate Fibre Channel HBAs only to VMkernel To administer, use VMware Management Interface or vmkfstools

Do not rescan SCSI adapters


14/1614


14

ESX Server 2.0.1 and Multipathing

Multipathing allows a SAN LUN to continue to beavailable in the event of a hardware failure Manual load-balancing support in ESX 2.0: administrator

may set preferred paths for each LUN

ESX Server supports failover with any supportedHBAs Failover occurs automatically, with a 30-60 second delay


15/1615


15

Setting Preferred Paths

View list of paths to storage# cat /proc/vmware/scsi/vmhba0/0:1[]Paths:fixedvmhba0:0:1 on*#vmhba1:0:1 on

Set your desired policy

echo "preferred vmhba1:0:1" > 0:1echo "policy mru" > 0:1

Save with vmkmultipath -S

Active

Preferred


16/16

ESX Server System Management IIModule 6

Questions?

3103047 16 Storage Area Networks

Documents

Transcript of 3103047 16 Storage Area Networks