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iSCSI SAN Configuration GuideUpdate 2 and later for

ESX Server 3.5, ESX Server 3i version 3.5, VirtualCenter 2.5


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VMware, Inc.3401 Hillview Ave.Palo Alto, CA 94304www.vmware.com

2 VMware, Inc.

iSCSI SAN Configuration Guide

You can find the most up-to-date technical documentation on our Web site at:

http://www.vmware.com/support/

The VMware Web site also provides the latest product updates.

If you have comments about this documentation, submit your feedback to:

[email protected]

20072009 VMware, Inc. All rights reserved. This product is protected by U.S. and internationalcopyright and intellectual property laws. VMware products are covered by one or more patentslisted athttp://www.vmware.com/go/patents.

VMware, the VMware boxes logo and design, Virtual SMP and VMotion are registered trademarks ortrademarks of VMware, Inc. in the United States and/or other jurisdictions. All other marks and namesmentioned herein may be trademarks of their respective companies.


Revision: 20090313Item: EN-000035-01
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Contents

AboutThisBook 7

1 UsingESXServerwithaStorageAreaNetwork 11UnderstandingVirtualization 12

NetworkVirtualization 12

StorageVirtualization 12

StorageAreaNetworkConcepts 15

Ports 16

MultipathingandPathFailover 17

StorageSystemTypes 17

TargetComparedtoLUNRepresentations 17

iSCSINamingConventions 19

OverviewofUsingESXServerwithaSAN 20

BenefitsofUsingESXServerwithaSAN 20

UseCases 21

FindingSANConfigurationInformation 21

BasicsofUsingSANStorageSystemswithan

ESXServer 22NetworkConfigurationandAuthentication 22

SharingaVMFSAcrossESXServers 22

MetadataUpdates 24

VolumeDisplayandRescan 24

LevelsofIndirection 24

DataAccess:VMFSorRDM 25

ThirdParty

Management

Applications 26Discovery,Authentication,andAccessControl 26

ErrorCorrection 27

UnderstandingVMFSandSANStorageChoices 27

ChoosingLargerorSmallerLUNs 27

MakingLUNDecisions 28

TipsforMakingLUNDecisions 29
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-


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UnderstandingDataAccess 30

AccessingDataonaSAN 30

HowVirtualMachinesAccessData 30

HowVirtualMachinesAccessDataonaSAN 31

PathManagementandFailover 32

SCSIStorageStackFailover 32

NICTeamingandFailover 33

ArrayBasedFailover 33

ChoosingVirtualMachineLocations 35

DesigningforServerFailure 36

UsingVMwareHA 36ServerFailoverandStorageConsiderations 36

2 InstallationofiSCSIInitiatorsandStorage 37PreparingforiSCSIStorageSetup 37

ESXServerSANRequirements 38

Restrictions 38

Recommendations 39

SettingLUNAllocations 39

SettingUpHardwareiSCSIInitiatorsandStorage 40

InstallingandViewingHardwareiSCSIInitiators 40

ConfiguringHardwareiSCSIInitiators 41

AddingHardwareInitiatediSCSIStorage 47

SettingAdditionalParameters 50

SettingUpSoftwareiSCSIInitiatorsandStorage 50NetworkingConfigurationforSoftwareiSCSIStorage 50

ConfiguringSoftwareiSCSIInitiators 56

ViewingSoftwareiSCSIInitiators 60

AddingSoftwareInitiatediSCSIStorage 62

3 ModifyingSANStorageSystemswithESXServer 65

SetupOverview 66GeneralConsiderations 66

EMCCLARiiONStorageSystems 67

EMCCLARiiONAX100iandAX150iandRDM 68

PushingHostConfigurationChangestotheStorageSystem 68

EMCSymmetrixStorageSystems 68

HPStorageWorksStorageSystems 69

HPStorageWorksMSA 69HPStorageWorksEVA 71


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Contents

NetworkApplianceStorageSystems 71

Multipathing 71

SettingLUNTypeandInitiatorGroupType 72

ProvisioningStorage 72

EqualLogicStorageSystems 74

LeftHandNetworksSAN/iQStorageSystems 75

BasicConfiguration 75

AutomaticVolumeResignaturing 75

4 BootingfromaSANwithESXServerSystems 77BootingfromaSANOverview 77

BenefitsofBootingfromaSAN 78

DecidingtoBootFromaSAN 78

EnablingBootingfromaSAN 79

PreparingtheSAN 79

ConfiguringiSCSIHBAstoBootfromaSAN 81

5 ManagingESXServerSystemsThatUseSANStorage 85IssuesandSolutions 86

GuidelinesforAvoidingSANProblems 86

GettingInformation 87

ViewingHBAInformation 87

ViewingDatastoreInformation 88

ResolvingDisplayIssues 89

UnderstandingLUNNamingintheDisplay 89

ResolvingIssueswithLUNsThatAreNotVisible 89

UsingRescan 90

RemovingDatastores 91

AdvancedLUNDisplayConfiguration 92

ChangingtheNumberofLUNsScannedbyUsingDisk.MaxLUN 92

MaskingLUNsbyUsingDisk.MaskLUNs 93

ChangingSparseLUNSupportbyUsingDiskSupportSparseLUN 94

Multipathing 94

ViewingtheCurrentMultipathingState 94

ActivePaths 97

SettingaLUNMultipathingPolicy 97

DisablingandEnablingPaths 98

SettingthePreferredPath(FixedPathPolicyOnly) 99

PathManagementandManualLoadBalancing 100PathFailover 101


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VMkernelConfiguration 102

SharingDiagnosticPartitions 102

AvoidingandResolvingSANProblems 103

OptimizingSANStoragePerformance 103

StorageSystemPerformance 104

ServerPerformance 104

NetworkPerformance 105

ResolvingPerformanceIssues 108

MonitoringPerformance 108

CheckingEthernetSwitchStatistics 109

ResolvingPathThrashing 109

UnderstandingPathThrashing 110

EqualizingDiskAccessBetweenVirtualMachines 111

RemovingVMFS2Drivers 112

ReducingSCSIReservations 112

SettingMaximumQueueDepthforSoftwareiSCSI 112

SANStorageBackupConsiderations 113

SnapshotSoftware 114UsingaThirdPartyBackupPackage 114

ChoosingYourBackupSolution 115

LayeredApplications 115

ArrayBased(ThirdParty)Solution 116

FileBased(VMFS)Solution 116

VMFSVolumeResignaturing 117

MountingOriginal,

Snapshot,

or

Replica

VMFS

Volumes 117

UnderstandingResignaturingOptions 118

A MultipathingChecklist 121

B Utilities 123esxtopUtility 123

storageMonitorUtility 124Options 124

Examples 125

esxcfgswiscsiUtility 125

esxcfghwiscsiUtility 126

vmkpingUtility 126

Index 127


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Thisbook,theiSCSISANConfigurationGuide,explainshowtouseanESXServer

systemwithastorageareanetwork(SAN).Themanualdiscussesconceptual

background,installationrequirements,andmanagementinformationinthesetopics:

UsingESXServerwithaSANDiscussesrequirements,differencesinSANsetup

ifESXServerisused,andhowtomanagethetwosystemstogether.

EnablingyourESXServersystemtobootfromaLUNonaSANDiscusses

requirements,limitations,andmanagementofbootingfromaSAN.

TheiSCSISANConfigurationGuidecoversbothESXServer3.5andESXServer3i

version3.5.Foreaseofdiscussion,thisbookusesthefollowingproductnaming

conventions:

FortopicsspecifictoESXServer3.5,thisbookusesthetermESXServer3.

FortopicsspecifictoESXServer3iversion3.5,thisbookusestheterm

ESXServer3i.

Fortopicscommontobothproducts,thisbookusesthetermESXServer.

Whentheidentificationofaspecificreleaseisimportanttoadiscussion,thisbook

referstotheproductbyitsfull,versionedname.

WhenadiscussionappliestoallversionsofESXServerforVMwareInfrastructure3,

thisbookusesthetermESXServer3.x.

About This Book

NOTE ForinformationonFibreChannel(FC)orNFSstoragedevices,seetheFibre

ChannelSAN

Configuration

Guide

and

the

ESX

Server

Configuration

Guide.


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8 VMware, Inc.

Intended Audience

TheinformationpresentedinthismanualiswrittenforexperiencedWindowsorLinux

systemadministratorswhoarefamiliarwithvirtualmachinetechnologydatacenteroperations.

Document Feedback

VMwarewelcomesyoursuggestionsforimprovingourdocumentation.Ifyouhave

comments,sendyourfeedbackto:

[email protected]

VMware Infrastructure Documentation

TheVMwareInfrastructuredocumentationconsistsofthecombinedVMware

VirtualCenterandESXServerdocumentationset.

Abbreviations Used in FiguresThefiguresinthisbookusetheabbreviationslistedinTable 1.

Technical Support and Education Resources

Thefollowingsectionsdescribethetechnicalsupportresourcesavailabletoyou.

To accessthecurrentversionsofthisbookandotherbooks,goto:

http://www.vmware.com/support/pubs

Table 1. Abbreviations

Abbreviation Description

database VirtualCenterdatabase

datastore Storageforthemanagedhost

dsk# Storagediskforthemanagedhost

hostn VirtualCentermanagedhosts

SAN Storageareanetworktypedatastoresharedbetweenmanagedhosts

tmplt Template

user# Userwithaccesspermissions

VC VirtualCenter

VM# Virtualmachinesonamanagedhost
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VMware, Inc. 9

About This Book

Online and Telephone Support

Useonlinesupporttosubmittechnicalsupportrequests,viewyourproductand

contractinformation,andregisteryourproducts.Goto:

http://www.vmware.com/support

Customerswithappropriatesupportcontractsshouldusetelephonesupportforthe

fastestresponseonpriority1issues.Goto:

http://www.vmware.com/support/phone_support.html

Support Offerings

FindouthowVMwaresupportofferingscanhelpmeetyourbusinessneeds.Goto:

http://www.vmware.com/support/services

VMware Education Services

VMwarecourses

offer

extensive

hands

on

labs,

case

study

examples,

and

course

materialsdesignedtobeusedasonthejobreferencetools.Formoreinformationabout

VMwareEducationServices,goto:

http://mylearn1.vmware.com/mgrreg/index.cfm
http://www.vmware.com/supporthttp://www.vmware.com/support/phone_support.htmlhttp://www.vmware.com/support/serviceshttp://mylearn1.vmware.com/mgrreg/index.cfmhttp://mylearn1.vmware.com/mgrreg/index.cfmhttp://www.vmware.com/support/serviceshttp://www.vmware.com/support/phone_support.htmlhttp://www.vmware.com/support


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1

YoucanuseESXServerinconjunctionwithastorageareanetwork(SAN),aspecialized

highspeednetworkthatconnectscomputersystemstohighperformancestorage

subsystems.UsingESXServertogetherwithaSANprovidesextrastoragefor

consolidation,improvesreliability,andhelpswithdisasterrecovery.

TouseESXServereffectivelywithaSAN,youmusthaveaworkingknowledgeof

ESX ServersystemsandSANconcepts.Also,whenyousetupESXServerhoststouse

iSCSISANstoragesystems,specialconsiderationsarenecessary.Formoreinformation

aboutusingESXServer,seetheESXServerConfigurationGuide.

Thischapterdiscussesthefollowingtopics:

UnderstandingVirtualizationonpage 12

StorageAreaNetworkConceptsonpage 15

OverviewofUsingESXServerwithaSANonpage 20

BasicsofUsingSANStorageSystemswithanESXServeronpage 22

UnderstandingVMFSandSANStorageChoicesonpage 27

UnderstandingDataAccessonpage 30

PathManagementandFailoveronpage 32

ChoosingVirtualMachineLocationsonpage 35

DesigningforServerFailureonpage 36

Using ESX Server with a

Storage Area Network

1


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Chapter 1 Using ESX Server with a Storage Area Network

Figure 11givesanoverviewofstoragevirtualization.ItillustratesstorageusingVMFS

andstorageusingrawdevicemapping.ItalsoshowshowiSCSIstorageisaccessed

througheitheriSCSIHBAsorbyusingageneralpurposeNICthatusesiSCSIinitiator

software.

Figure 1-1. iSCSI SAN Storage Virtualization

iSCSI Initiators

Toaccessremotetargets,yourESXServerhostusesiSCSIinitiators.Initiatorstransport

SCSIrequestsandresponsesbetweentheESXServersystemandthetargetstorage

deviceontheIPnetwork.

ESXServersupportshardwarebasedandsoftwarebasediSCSIinitiators:

Hardware iSCSI initiator. Athirdpartyhostbusadapter(HBA)withiSCSIover

TCP/IPcapability.ThisspecializediSCSIadapterisresponsibleforalliSCSIprocessing

andmanagement.

ESX Server

VMFS

VMware virtualization layer

.dsk

LUN1 LUN2 LUN5

virtualmachine

SCSIcontroller(Buslogic

orLSI Logic)

virtualmachine

SCSIcontroller(Buslogic

orLSI Logic)

virtual diskvirtual disk

LAN LAN

hardware

iSCSI

initiator

(HBA)ethernet

NIC

software

iSCSI initiator


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Software iSCSI initiator. CodebuiltintotheVMkernelthatallowsanESXServerto

connecttotheiSCSIstoragedevicethroughstandardnetworkadapters.Thesoftware

initiatorhandlesiSCSIprocessingwhilecommunicatingwiththenetworkadapter

throughthenetworkstack.Withthesoftwareinitiator,youcanuseiSCSItechnologywithoutpurchasingspecializedhardware.

Thediagram

in

Figure 1

1depicts

two

virtual

machines

that

use

different

types

of

iSCSI

initiators.

InthefirstexampleofiSCSIstorageconfiguration,theESXServersystemusesthe

hardwareiSCSIinitiator.ThisspecializediSCSIinitiatorsendsiSCSIpacketstoadisk

overaLAN.

Inthesecondexample,theESXServersystemisconfiguredwiththesoftwareiSCSI

initiator.Usingthesoftwareinitiator,theESXServersystemconnectstoaLANthrough

anexistingNIC.

Disk Configuration Options

YoucanconfigurevirtualmachineswithmultiplevirtualSCSIdrives.Forsupported

drivers,seetheStorage/SANCompatibilityGuideat

www.vmware.com/support/pubs/vi_pubs.html.Theguestoperatingsystemcanplace

limitationsonthetotalnumberofSCSIdrives.

AlthoughallSCSIdevicesarepresentedasSCSItargets,physicalimplementation

alternativesareavailable:

Virtualmachine.vmdkfilestoredonaVMFSvolume.SeeVirtualMachineFile

Systemonpage 15.

DevicemappingtoaSANlogicalunit(LUN).SeeRawDeviceMappingon

page 15.

Fromthestandpointofthevirtualmachine,eachvirtualdiskappearsasifitwerea

SCSIdriveconnectedtoaSCSIinitiator.Whethertheactualphysicaldiskdeviceis

beingaccessedthroughSCSI,iSCSI,orFCcontrollersistransparenttotheguest

operatingsystemandtoapplicationsrunningonthevirtualmachine.

NOTE GuestoperatingsystemsinvirtualmachinescannotseeiSCSIstoragedirectly.

Totheguestoperatingsystems,iSCSIstorageattachedtotheESXServersystem

appearstobeavailablethroughaSCSIHBA.
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Virtual Machine File System

Inasimpleconfiguration,thevirtualmachinesdisksarestoredasfileswithinavirtual

machinefile

system

(VMFS).

When

guest

operating

systems

issue

SCSI

commands

to

theirvirtualdisks,thevirtualizationlayertranslatesthesecommandstoVMFSfile

operations.

ESXServersystemsuseVMFStostorevirtualmachinefiles.TominimizediskI/O

overhead,VMFSisoptimizedtorunmultiplevirtualmachinesasoneworkload.VMFS

alsoprovidesdistributedlockingforyourvirtualmachinefiles,sothatyourvirtual

machinescanoperatesafelyinaSANenvironmentwheremultipleESXServerhosts

shareaset

of

LUNs.

VMFSisfirstconfiguredaspartoftheESXServerinstallation.Whenyoucreateanew

VMFS3volume,itmustbe1200MBorlarger.SeetheInstallationGuide.Itcanthenbe

customized,asdiscussedintheESXServerConfigurationGuide.

AVMFSvolumecanbeextendedover32physicalstorageextents,includingSAN

LUNsandlocalstorage.Thisallowspoolingofstorageandflexibilityincreatingthe

storagevolumenecessaryforyourvirtualmachine.WiththenewESX3LogicalVolume

Manager(LVM),youcanextendavolumewhilevirtualmachinesarerunningonthe

volume.ThisletsyouaddnewspacetoyourVMFSvolumesasyourvirtualmachine

needsit.

Raw Device Mapping

Arawdevicemapping(RDM)isaspecialfileinaVMFSvolumethatactsasaproxyfor

a

raw

device.

The

RDM

provides

some

of

the

advantages

of

a

virtual

disk

in

the

VMFS

filesystem,whilekeepingsomeadvantagesofdirectaccesstophysicaldevices.

RDMmightberequiredifyourunSANSnapshotorotherlayeredapplicationsinthe

virtualmachine.RDMsbetterenablesystemstousethehardwarefeaturesinherentto

SANstoragesystems.SeeUsingRawDeviceMappingintheESXServer

ConfigurationGuide.

Storage Area Network ConceptsIfyouareanESXServeradministratorplanningtosetupESXServerhoststoworkwith

SANs,youmusthaveaworkingknowledgeofSANconcepts.Youcanfindinformation

aboutSANinprintandontheInternet.Twowebbasedresourcesare:

www.searchstorage.com

www.snia.org
http://www.searchstorage.com/http://www.searchstorage.com/http://www.snia.org/http://www.snia.org/http://www.searchstorage.com/


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IfyouarenewtoSANtechnology,readthefollowingsectiontofamiliarizeyourself

withthebasicterminologythisdocumentuses.TolearnaboutbasicSANconcepts,see

theSANConceptualandDesignBasicswhitepaperat

http://www.vmware.com/support/pubs.

ThisconfigurationguidediscussesiSCSISANs,whichuseEthernetconnections

betweencomputersystems,orhostservers,andhighperformancestoragesubsystems.

TheSANcomponentsincludehostbusadapters(HBAs)orNetworkInterface Cards

(NICs)inthehostservers,switchesandroutersthattransportthestoragetraffic,cables,

storageprocessors(SPs),andstoragedisksystems.

Totransfer

traffic

from

host

servers

to

shared

storage,

the

SAN

uses

the

iSCSI

protocol

thatpackagesSCSIcommandsintoiSCSIpacketsandtransmitstheseonanEthernet

network.

Ports

Inthecontextofthisdocument,aportistheconnectionfromadeviceintotheSAN.

EachnodeintheSAN,ahost,storagedevice,andEthernetswitchhasoneormoreports

thatconnectittotheSAN.Portsareidentifiedinanumberofways:

IP address EachiSCSIporthasanIPaddressassociatedwithitsothatroutingand

switchingequipmentonyournetworkcanestablishtheconnectionbetweentheserver

andstorage.ThisisjustliketheIPaddressyouassigntoyourcomputertogetaccessto

yourcompanysnetworkortheInternet.

iSCSI Name Auniquenameforidentifyingtheport.TheiSCSInamestartswith

eitheriqn.

(for

iSCSI

qualified

name)

or

eui.

(for

extended

unique

identifier).

Multiple

iSCSIdevicescanbepresent,withmultipleiSCSInames,andcanbeconnectedthrough

asinglephysicalEthernetport.iSCSInamesareusuallysettoauniquedefaultvalue,

anddonotneedtobesetbytheuser.AnexampleofaVMwaregeneratediSCSIname

isiqn.199801.com.vmware:iscsitestox68158ef2.

iSCSI alias AmoremanageablenameforaniSCSIdeviceorport,usedinsteadofthe

iSCSIname.iSCSIaliasesarenotunique,andareintendedtobejustafriendlyname

toassociatewithaport.OnanESXServersystem,thedefaultiSCSIaliasisthenameofthesystem.
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Multipathing and Path Failover

Whentransferringdatabetweenthehostserverandstorage,theSANusesa

multipathingtechnique.

Multipathing

allows

you

to

have

more

than

one

physical

path

fromtheESXServerhosttoaLUNonastoragesystem.

IfapathoranycomponentalongthepathHBAorNIC,cable,switchorswitchport,

orstorageprocessorfails,theserverselectsanotheroftheavailablepaths.Theprocess

ofdetectingafailedpathandswitchingtoanotheriscalledpathfailover.

Storage System Types

Storagedisksystemscanbeofthefollowingtypes:

Anactiveactivestoragesystem,whichallowsaccesstotheLUNssimultaneously

throughallthestorageportsthatareavailablewithoutsignificantperformance

degradation.Allthepathsareactiveatalltimes(unlessapathfails).

Anactivepassivestoragesystem,inwhichoneportoranSPisactivelyproviding

accesstoagivenLUN.TheotherportsorSPsactasbackupfortheLUNandcan

beactivelyprovidingaccesstootherLUNI/O.I/Ocanbesentonlytoanactive

port.Ifaccessthroughtheprimarystorageportfails,oneofthesecondaryportsor

storageprocessorsbecomesactive,eitherautomaticallyorthroughadministrator

intervention.

Avirtualportstoragesystem,whichallowsaccesstoallavailablevolumesthrough

asinglevirtualport.Theseareactiveactivestoragedevices,buthidetheirmultiple

connectionsthoughasingleport.TheESXServermultipathinghasnoknowledge

ofthemultipleconnectionstothestorage.Thesestoragesystemshandleport

failoverandconnectionbalancingtransparently.Thisisoftenreferredtoas

transparentfailover.

Target Compared to LUN Representations

DifferentiSCSIstoragevendorspresentstoragetoserversindifferentways.Some

vendorspresentmultipleLUNsonasingletarget,whileotherspresentmultipletargetswithoneLUNeach(seeFigure 12).WhilethewaythestorageisusedbyanESXServer

issimilar,thewaytheinformationispresentedthroughadministrativetoolsis

different.


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Figure 1-2. Target compared to LUN Representations

Threevolumes(orLUNs,theSCSItermforlogicalunit,whichmeansaportionof

storage)areavailableineachoftheseconfigurations.Inthefirstcase,ESXServersees

onetarget(representedbyanIQNname)butthattargethasthreeLUNsthatcanbe

used.EachoftheLUNsrepresentindividualstoragevolumes.Inthesecondcase,the

ESXServerseesthreedifferenttargets,representedbythreeseparateIQNnames.

Each ofthesetargetshasoneLUN.

Targetnumbering(thoughnotIQNtargetnaming)isdecidedbytheESXServer,so

targets

that

are

shared

by

different

ESX

Server

systems

might

not

have

the

same

target

number(vmhba1:2:3:4,wherethe2showsthetargetnumberposition).Also,multiple

pathstothesamestoragearerepresentedbydifferenttargetnumbers.

LUNnumberingisdecidedbythestoragesystem,soLUNnumbersacrosspathsand

multipleESXServersystemsalwaysstaythesame(vmhba1:2:3:4,wherethe3shows

theLUNposition).Onstoragesystemswithmultipletargets,likethesecondexample

above,theLUNnumberisalwayszero(0).

ESXServerbasediSCSIinitiatorsestablishonlyoneconnectiontoeachtarget.This meansstoragesystemswithasingletargetcontainingmultipleLUNshaveall

LUNtrafficonthatoneconnection.WithasystemthathasthreetargetswithoneLUN

each,threeconnectionsexistbetweenanESXServerandthethreevolumesavailable.

Thisinformationisusefulwhenyouaretryingtoaggregatestoragetrafficonmultiple

connectionsfromanESXServerwithmultipleiSCSIHBAs,wheretrafficforonetarget

canbesettoaparticularHBA,whiletrafficforanothertargetcanuseadifferentHBA.

ThisdocumentusesthetermLUNtomeanavolumeavailablefromastoragesystem,

evenifthatLUNistheonlyoneavailableonaniSCSItarget.Thismeaningistoavoid

confusionwithotherusesofthewordvolumeinthisdocument.Althoughstorage

systemvendorsmightnotcalltheirvolumesLUNs,thisisultimatelyhowtheyare

representedtotheESXServerstoragesystem.

storage array

target

LUN LUN LUN

storage array

target target target

LUN LUN LUN


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iSCSI Naming Conventions

iSCSIusesanametouniquelyidentifyaniSCSIdevice,eithertargetorinitiator.

This nameis

similar

to

the

WorldWide

Name

associated

with

Fibre

Channel

devices,

usedasawaytouniversallyidentifythedevice.

iSCSInamesareformattedtwodifferentways.ThefirstisbyaniSCSIqualifiedname,

commonlyreferredtoasanIQNname.Thesecond,muchlesscommonmethod,is

throughanenterpriseuniqueidentifier,alsoreferredtoasanEUIname.

iSCSI Qualified Names

iSCSIqualifiednamestaketheformiqn.yyyy-mm.naming-authority:unique name

yyyy-mm istheyearandmonthwhenthenamingauthoritywasestablished.

naming-authority isusuallyreversesyntaxoftheInternetdomainnameofthe

namingauthority.Forexample,theiscsi.vmware.com namingauthoritycouldhavethe

iSCSIqualifiednameformofiqn.199801.com.vmware.iscsi. Thevmware.comdomain

namewasregisteredinJanuaryof1998,andiscsiisasubdomain,maintainedby

vmware.com.

unique name theiscsi.vmware.comnamingauthorityneedstoensurethatanynames

assignedfollowingthecolonareunique,suchas:

iqn.199801.com.vmware.iscsi:name1



Enterprise Unique Identifiers

Enterpriseuniqueidentifierstaketheformeui..

Forexample,eui.0123456789ABCDEF.

The16hexadecimaldigitsaretextrepresentationsofa64bitnumberofanIEEEEUI

(extendedunique

identifier)

format.

The

top

24

bits

are

acompany

ID

that

IEEE

registerswithaparticularcompany.Thelower40bitsareassignedbytheentity

holdingthatcompanyID,andmustbeunique.

Inmanycases,theIQNformatischosenovertheEUIformatforreadabilityandasa

moreuserfriendlymethodofassigningnames.

iSCSI SAN C fi ti G id


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20 VMware, Inc.

Overview of Using ESX Server with a SAN

SupportforQLogiciSCSIHBAsandsoftwarebasediSCSIimplementationsallowan

ESXServer

system

to

be

connected

to

iSCSI

storage.

You

can

then

use

iSCSI

storage

volumestostorevirtualmachineconfigurationinformationandapplicationdata.

UsingESXServerwithaSANimprovesflexibility,efficiency,andreliability.Italso

supportscentralizedmanagementaswellasfailoverandloadbalancingtechnologies.

Benefits of Using ESX Server with a SAN

UsingaSANwithESXServerallowsyoutoimproveyourenvironmentsfailure

resilience:

YoucanstoredataredundantlyandconfiguremultipleEthernetpathstoyour

iSCSIstorage,eliminatingasinglepointoffailure.Yourenterpriseisnotcrippled

whenonedatacenterbecomesunavailable.

ESXServersystemsprovidemultipathingbydefaultandautomaticallysupportit

foreveryvirtualmachine.SeePathManagementandFailoveronpage 32.

UsingaSANwithESXServersystemsextendsfailureresistancetotheserver.

WhenyouuseSANstorage,allapplicationscaninstantlyberestartedafterhost

failure.SeeDesigningforServerFailureonpage 36.

UsingESXServerwithaSANmakeshighavailabilityandautomaticloadbalancing

affordableformoreapplicationsthanifdedicatedhardwareisusedtoprovidestandby

services:

Ifvirtualmachinesareusedasstandbysystemsforexistingphysicalservers,sharedstorageisessentialandaSANisthebestsolution.

UsetheVMwareVMotioncapabilitiestomigratevirtualmachinesseamlessly

fromonehosttoanother.

UseVMwareHighAvailability(HA)inconjunctionwithaSANforacoldstandby

solutionthatguaranteesanimmediate,automaticresponse.

UseVMwareDistributedResourceScheduler(DRS)tomigratevirtualmachinesfromonehosttoanotherforloadbalancing.BecausestorageisonaSANstorage

system,applicationscontinuerunningseamlessly.

IfyouuseVMwareDRSclusters,putanESXServerhostintomaintenancemode

tohavethesystemmigrateallrunningvirtualmachinestootherESXServerhosts.

Youcanthenperformupgradesorothermaintenanceoperations.



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VMware, Inc. 21


Thetransportability andencapsulationofVMwarevirtualmachinescomplementsthe

sharednatureofiSCSIstorage.WhenvirtualmachinesarelocatedonSANbased

storage,youcanshutdownavirtualmachineononeserverandpowerituponanother

serverortosuspenditononeserverandresumeoperationonanotherserveronthesamenetworkinamatterofminutes.Thisallowsyoutomigratecomputingresources

whilemaintainingconsistentsharedaccess.

Use Cases

UsingESXServersystemsinconjunctionwithSANiseffectiveforthefollowingtasks:

Maintenance with zero downtime. Whenyouperformmaintenance,useVMwareDRSorVMotiontomigratevirtualmachinestootherservers.Ifsharedstorageisonthe

SAN,youcanperformmaintenancewithoutinterruptionstotheuser.

Load balancing. UseVMotionexplicitlyoruseVMwareDRStomigratevirtual

machinestootherhostsforloadbalancing.IfsharedstorageisonaSAN,youcan

performloadbalancingwithoutinterruptiontotheuser.

Storage consolidation and simplification of storage layout. Ifyou

are

working

withmultiplehosts,andeachhostisrunningmultiplevirtualmachines,thehosts

storageisnolongersufficientandexternalstorageisneeded.ChoosingaSANfor

externalstorageresultsinasimplersystemarchitecturewhilegivingyoutheother

benefitslistedinthissection.Youcanstartbyreservingalargevolumeandthen

allocateportionstovirtualmachinesasneeded.Volumeallocationandcreationfrom

thestoragedeviceneedstohappenonlyonce.

Disaster recovery. Havingall

data

stored

on

aSAN

can

greatly

facilitate

remote

storageofdatabackups.Inaddition,youcanrestartvirtualmachinesonremote

ESX Serverhostsforrecoveryifonesiteiscompromised.

Finding SAN Configuration Information

Inadditiontothisdocument,anumberofotherresourcescanhelpyouconfigureyour

ESXServersysteminconjunctionwithaSAN:

Useyourstoragevendorsdocumentationformostsetupquestions.Yourstorage

vendormightalsoofferdocumentationonusingthestoragesysteminan

ESX Serverenvironment.

TheFibreChannelSANConfigurationGuideDiscussestheuseofESXServerwith

FibreChannelstorageareanetworks.

TheVMwareI/OCompatibilityGuideListsthecurrentlyapprovedHBAs,HBA

drivers,anddriverversions.



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22 VMware, Inc.

TheVMwareStorage/SANCompatibilityGuideListscurrentlyapprovedstorage

systems.

TheVMwareReleaseNotesGiveinformationaboutknownissuesand

workarounds.

TheVMwareKnowledgeBaseHasinformationoncommonissuesand

workarounds.

Formoreinformation,seetheVMwareDocumentationWebsiteat

http://www.vmware.com/support/pubs.

Basics of Using SAN Storage Systems with anESX Server

UsingaSANinconjunctionwithanESXServerhostdiffersfromtraditionalSANusage

inavarietyofways,discussedinthissection.

Network Configuration and Authentication

BeforevolumesusingsoftwareiSCSIcanbediscovered,thestoragenetworkmustbe

configuredandauthenticationmighthavetobesetup.

ForsoftwareiSCSI,networkingfortheVMkernelneedstobeconfigured.Youcan

verifythenetworkconfigurationbyusingthevmkpingutility(seeAppendix B,

Utilities,onpage 123).ForhardwareiSCSI,networkparameters,suchas

IP address,subnetmask,anddefaultgatewaymustbeconfiguredontheHBA.

Checkandchangethedefaultinitiatornameifnecessary.

Thediscoveryaddressofthestoragesystemmustbesetandshouldbepingable

usingvmkping.

ForCHAPauthentication,enableitontheinitiatorandthestoragesystemside.

Afterauthenticationisenabled,itappliesforallofthetargetsthatarenotyet

discovered,butdoesnotapplytotargetsthatarealreadydiscovered.Afterthe

discoveryaddressisset,thenewvolumesdiscoveredareexposedandcanbeusedatthatpoint.

Sharing a VMFS Across ESX Servers

ESXServerVMFSisdesignedforconcurrentaccessfrommultiplephysicalmachines

andenforcestheappropriateaccesscontrolsonvirtualmachinefiles.Forbackground

informationon

VMFS,

see

Virtual

Machine

File

System

on

page 15.

For

additional

information,seetheESXServerConfigurationGuide.

http://www.vmware.com/support/pubshttp://www.vmware.com/support/pubs


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VMware, Inc. 23

p g g

VMFScan:

Coordinateaccesstovirtualdiskfiles.ESXServerusesfilelevellocks,whichthe

VMFSdistributedlockmanagermanages.

CoordinateaccesstoVMFSinternalfilesysteminformation(metadata).

BecausevirtualmachinesshareacommonVMFS,itmightbedifficulttocharacterize

peakaccessperiodsortooptimizeperformance.Youneedtoplanvirtualmachine

storageaccessforpeakperiods,butdifferentapplicationsmighthavedifferent

peakaccessperiods.ThemorevirtualmachinesaresharingaVMFS,thegreaterthe

potentialforperformancedegradationbecauseofI/Ocontention.

Figure 13showsseveralESXServersystemssharingthesameVMFSvolume.

Figure 1-3. Accessing Virtual Disk Files

NOTE SCSIreservationsareheldduringmetadataupdatestotheVMFSvolume.

ESX ServerusesshortlivedSCSIreservationsaspartofitsdistributedlockingprotocol.

NOTE VMwarerecommendsthatyouloadbalancevirtualmachinesoverservers,

CPU,andstorage.Runamixofvirtualmachinesoneachserversothatnotall

experiencehighdemandinthesameareaatthesametime.

VMFS volume

ESX

Server A

ESX

Server B

ESX

Server C

virtual

disk

files

VM1 VM2 VM3

disk1

disk2

disk3



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24 VMware, Inc.

Metadata Updates

AVMFSholdsfiles,directories,symboliclinks,RDMs,andsoon,alongwith

correspondingmetadata

for

these

objects.

Metadata

is

accessed

each

time

the

attributes

ofafileareaccessedormodified.Theseoperationsinclude,butarenotlimitedto:

Creating,growing,orlockingafile.

Changingafilesattributes.

Poweringavirtualmachineonoroff.

Volume Display and RescanASANisdynamic,andwhichvolumesareavailabletoacertainhostcanchangebased

onanumberoffactorsincluding:

NewvolumescreatedontheiSCSIstorage

Changestovolumeaccesscontrol

Changes

in

network

connectivity

TheVMkerneldiscoversvolumeswhenitbootsandthosevolumesarethenvisiblein

VIClient.Ifchangesaremadetothevolumes,youmustrescantoseethosechanges.

Levels of Indirection

IfyoureusedtoworkingwithtraditionalSANs,thelevelsofindirectioncaninitially

beconfusing.

Youcannotdirectlyaccessthevirtualmachineoperatingsystemthatusesthe

storage.With

traditional

tools,

you

can

monitor

only

the

VMware

ESX

Server

operatingsystem(butnotthevirtualmachineoperatingsystem).Youusethe

VI Clienttomonitorvirtualmachines.

Eachvirtualmachineis,bydefault,configuredwithonevirtualharddiskandone

virtualSCSIcontrollerduringinstallation.YoucanmodifytheSCSIcontrollertype

andSCSIbussharingcharacteristicsbyusingtheVIClienttoeditthevirtual

machinesettings,asshowninFigure 14.Youcanalsoaddharddiskstoyour

virtualmachine.

See

the

ESX

Server

Configuration

Guide.

CAUTION AfteryoucreateanewVMFSvolumeorextendanexistingVMFSvolume,

youmustrescantheSANstoragefromallESXServerhoststhatcouldseethatparticular

volume(LUN).Ifthisisnotdone,thesharedvolumemightbecomeinvisibletosome

ofthose

hosts.



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VMware, Inc. 25

Figure 1-4. Setting the SCSI Controller Type

TheHBAvisibletotheSANadministrationtoolsispartoftheESXServersystem,

notthevirtualmachine.

YourESXServersystemperformsmultipathingforyou.Multipathingsoftware

(suchasPowerPath)inthevirtualmachineisnotsupported(andnotrequired).

Data Access: VMFS or RDM

Bydefault,avirtualdiskiscreatedinaVMFSvolumeduringvirtualmachinecreation.

WhenguestoperatingsystemsissueSCSIcommandstotheirvirtualdisks,the

virtualizationlayertranslatesthesecommandstoVMFSfileoperations.SeeVirtualMachineFileSystemonpage 15.

AnalternativetoVMFSisusingRDMs.RDMsarespecialfilesinaVMFSvolumethat

actasaproxyforarawdevice.TheRDMgivessomeoftheadvantagesofavirtualdisk

intheVMFSwhilekeepingsomeadvantagesofdirectaccesstoaphysicaldevice.

See RawDeviceMappingonpage 15.


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VMware, Inc. 27

Access Control. ApolicysetupontheiSCSIstoragesystem.Mostimplementations

supportoneormoreofthreetypesofaccesscontrol:

Byinitiatorname

ByIPaddress

BytheCHAPprotocol

OnlyinitiatorsthatmeetallrulesattachedtotheiSCSIvolumecanaccessit.

Error Correction

ToprotecttheintegrityofiSCSIheadersanddata,theiSCSIprotocoldefineserror

correctionmethodsknownasheaderdigestsanddatadigests.Thesearedisabledby

default,buttheusercanenablethem.Thesedigestspertainto,respectively,theheader

andSCSIdatabeingtransferredbetweeniSCSIinitiatorsandtargets,inbothdirections.

Headeranddatadigestschecktheendtoend,noncryptographicdataintegrity

beyondtheintegritychecksthatothernetworkinglayersprovide,suchasTCPand

Ethernet.Theychecktheentirecommunicationpath,includingallelementsthatcan

changethenetworkleveltraffic,suchasrouters,switches,andproxies.

TheexistenceandtypeofthedigestsarenegotiatedwhenaniSCSIconnectionis

established.Whentheinitiatorandtargetagreeonadigestconfiguration,thisdigest

mustbeusedforalltrafficbetweenthem.

Enablingheaderanddatadigestsdoesrequireadditionalprocessingforboththe

initiatorandthetargetandcanaffectthroughputandCPUuseperformance.

Understanding VMFS and SAN Storage Choices

ThissectiondiscussestheavailableVMFSandSANstoragechoicesandgivesadviceon

howtomakethesechoices.

Choosing Larger or Smaller LUNs

DuringESXServerinstallation,youarepromptedtocreatepartitionsforyoursystem.

PlanhowtosetupstorageforyourESXServersystemsbeforeyouperforminstallation.

Chooseoneoftheseapproaches:

ManyLUNswithoneVMFSvolumeoneachLUN

OnelargeLUNormanyLUNswithasingleVMFSvolumespanningallLUNs

Youcan

have

at

most

one

VMFS

volume

per

LUN.

You

can,

however,

decide

to

use

one

largeLUNormultiplesmallLUNs.



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28 VMware, Inc.

Youmightwantfewer,largerLUNsforthefollowingreasons:

MoreflexibilitytocreatevirtualmachineswithoutaskingtheSANadministrator

formorespace.

Moreflexibilityforresizingvirtualdisks,doingsnapshots,andsoon

FewerLUNstoidentifyandmanage

Youmightwantmore,smallerLUNsforthefollowingreasons:

LesscontentiononeachVMFSbecauseoflockingandSCSIreservationissues.

Different

applications

might

need

different

RAID

characteristics. Moreflexibility(themultipathingpolicyanddisksharesaresetperLUN).

Making LUN Decisions

Whenthestoragecharacterizationforavirtualmachineisnotavailable,thereisoften

nosimpleanswerwhenyouneedtodecideontheLUNsizeandnumberofLUNsto

use.Youcanuseoneofthefollowingapproaches:

Predictivescheme

Adaptivescheme

Predictive Scheme

Inthepredictivescheme,you:

CreateseveralLUNswithdifferentstoragecharacteristics.

BuildaVMFSvolumeineachLUN(andlabeleachvolumeaccordingtoits

characteristics).

Locate

each

application

in

the

appropriate

RAID

for

its

requirements. Usedisksharestodistinguishhighpriorityfromlowpriorityvirtualmachines.

DisksharesarerelevantonlywithinagivenESXServerhost.Thesharesassigned

tovirtualmachinesononeESXServerhosthavenoeffectonvirtualmachineson

otherESXServerhosts.

NOTE Youcandivideyourdatacenterintoserversthatarebestconfiguredwithfewer,

largerLUNsandotherserversthatusemore,smallerLUNs.


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32 VMware, Inc.

Path Management and Failover

YoucanusemultiplewaystomanagepathsandfailoverinaniSCSISAN:

SCSIstoragestackfailover

NICteamingandfailover

Arraybasedfailover

SCSI Storage Stack Failover

ESXServer

supports

multipathing

to

maintain

aconstant

connection

between

the

servermachineandthestoragedeviceincaseofthefailureofanHBAorswitch.

Multipathingsupportdoesnotrequirespecificfailoverdrivers.

Tosupportpathswitching,theservertypicallyhastwoormoreHBAsavailablefrom

whichthestoragesystemcanbereachedusingoneormoreswitches.Alternatively,the

setupmightincludeoneHBAandtwostorageprocessorssothattheHBAcanusea

differentpathtoreachthestoragesystem.

Figure 1-5. Multipathing and Failover

InFigure 15,multiplepathsconnecteachserverwiththestoragedevice.Forexample,

ifHBA1orthelinkbetweenHBA1andthenetworkfails,HBA2takesoverand

providesthe

connection

between

the

server

and

the

network.

The

process

of

one

HBA

takingoverforanotheriscalledHBAfailover.

ESXServer

ESXServer

SP

iSCSI storage

SP

HBA2 HBA1softwareinitiator

IP network



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VMware, Inc. 33

Similarly,ifSP1failsorthelinksbetweenSP1andtheswitchesbreaks,SP2takesover

andprovidestheconnectionbetweentheswitchandthestoragedevice.Thisprocessis

calledSPfailover.ESXServersupportsbothHBAandSPfailoverwithitsmultipathing

capability.

Youcanchooseamultipathingpolicyforyoursystem,eitherFixedorMostRecently

Used.IfthepolicyisFixed,youcanspecifyapreferredpath.EachLUN(disk)thatis

visibletotheESXServerhostcanhaveitsownpathpolicy.Forinformationonviewing

thecurrentmultipathingstateandonsettingthemultipathingpolicy,see

Multipathingonpage 94.

NIC Teaming and Failover

WithsoftwareiSCSI,youcanconnectasinglevirtualVMKerneliSCSInetworkswitch

tomultiplephysicalEthernetadaptersbyusingtheVMwareInfrastructurefeature

calledNICteaming.NICteamingprovidesnetworkredundancyandsomeload

balancingcapabilitiesforiSCSIconnectionsbetweenESXServerandstoragesystems.

SimilartotheSCSImultipathcapabilities,NICteamingprovidesfailoverifconnections

orportsontheESXServersystemfail.

NICteamingpathsdonotshowupasmultiplepathstostorageinESXServer

configurations.NICteamingishandledentirelybythenetworklayerandmustbe

configuredandmonitoredseparatelyfromtheESXServerSCSIstoragemultipath

configuration.

Array-Based Failover

SomeiSCSIstoragesystemsmanagepathuseoftheirportsautomatically

(transparentlytoESXServer).Whenusingoneofthesestoragesystems,ESXServer

doesnotseemultipleportsonthestorageandcannotchoosethestorageportit

connectsto.ThesesystemshaveasinglevirtualportaddressthatESXServerusesto

initiallycommunicate.Duringthisinitialcommunication, thestoragesystemcan

redirectESXServertocommunicatewithanotherportonthestoragesystem.TheiSCSI

initiatorsinESXServerobeythisreconnectionrequestandconnectwithadifferentport

onthesystem.Thestoragesystemusesthistechniquetospreadtheloadacrossavailableports.

IfESXServerlosesconnectiontooneoftheseports,itautomaticallyattemptsto

reconnectwiththevirtualportofthestoragesystem,andshouldberedirectedtoan

active,usableport.Thisreconnectionandredirectionhappensquicklyandgenerally

doesnotdisruptrunningvirtualmachines.Thesestoragesystemscanalsorequestthat

iSCSIinitiatorsreconnecttothesystem,tochangewhichstorageporttheyare

connectedto.Thisallowsthemosteffectiveuseofthemultipleports.



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34 VMware, Inc.

Figure 16showsanexampleofportredirection.ESXServerattemptstoconnecttothe

10.0.0.1virtualport.Thestoragesystemredirectsthisrequestto10.0.0.2.ESXServer

connectswith10.0.0.2andusesthisportforI/Ocommunication.

Figure 1-6. Port Redirection

Iftheportonthestoragesystemthatisactingasthevirtualportbecomesunavailable,

thestoragesystemreassignstheaddressofthevirtualporttoanotherportonthe

system.Figure 17showsanexampleofthistypeofportreassignment.Inthiscase,the

virtualport10.0.0.1becomesunavailableandthestoragesystemreassignsthevirtual

portIPaddresstoadifferentport.Thesecondportrespondstobothaddresses.

Figure 1-7. Port Reassignment

NOTE Thestoragesystemdoesnotalwaysredirectconnections.Theportat10.0.0.1

couldbeusedfortraffic,also.

NOTE VirtualmachineI/Ocanbedelayedforuptosixtysecondswhilefailovertakes

place,particularlyonanactivepassivearray.ThisdelayallowstheSANtostabilizeits

configurationaftertopologychanges.Withactivepassivearrayswithpathpolicy

Fixed,paththrashingcanbeaproblem.SeeResolvingPathThrashingonpage 109.

storage

10.0.0.1

10.0.0.2

ESX Server Connect to storage at 10.0.0.1

Reconnect to 10.0.0.2

storage

10.0.0.1

10.0.0.2

ESX Server iSCSI storage traffic

storage

10.0.0.1

10.0.0.2

storage

10.0.0.1

10.0.0.110.0.0.2



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VMware, Inc. 35

Choosing Virtual Machine Locations

Whenyoureworkingonoptimizingperformanceforyourvirtualmachines,storage

locationis

an

important

factor.

A

trade

off

always

exists

between

expensive

storage

that

offershighperformanceandhighavailabilityandstoragewithlowercostandlower

performance.Storagecanbedividedintodifferenttiersdependingonanumberof

factors:

High Tier. Offershighperformanceandhighavailability.Mightofferbuiltin

snapshotstofacilitatebackupsandpointintime(PiT)restorations.Supports

replication,fullSPredundancy,andSASdrives.Useshighcostspindles.

Mid Tier. Offersmidrangeperformance,loweravailability,someSPredundancy,and

SCSIorSASdrives.Mayoffersnapshots.Usesmediumcostspindles.

Lower Tier. Offerslowperformance,littleinternalstorageredundancy.Useslowend

SCSIdrivesorSATA(seriallowcostspindles).

Notallapplicationsneedtobeonthehighestperformance,mostavailablestorageat

leastnotthroughouttheirentirelifecycle.

Whenyoudecidewheretoplaceavirtualmachine,askyourselfthesequestions:

Howcriticalisthevirtualmachine?

Whatareitsperformanceandavailabilityrequirements?

WhatareitsPiTrestorationrequirements?

Whatareitsbackuprequirements?

Whatareitsreplicationrequirements?

Avirtualmachinemightchangetiersthroughoutitslifecyclebecauseofchangesin

criticalityorchangesintechnologythatpushhighertierfeaturestoalowertier.Criticalityisrelativeandmightchangeforavarietyofreasons,includingchangesinthe

organization,operationalprocesses,regulatoryrequirements,disasterplanning,and

so on.

NOTE Ifyouneedsomeofthefunctionalityofthehightier,suchassnapshots,butdo

notwanttopayforit,youmightbeabletoachievesomeofthehighperformance

characteristicsinsoftware.Forexample,youcancreatesnapshotsinsoftware.



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36 VMware, Inc.

Designing for Server Failure

TheRAIDarchitectureofSANstorageinherentlyprotectsyoufromfailureatthe

physical

disk

level.

A

SAN

provides

multiple

paths

between

servers

and

storage,

which

protectsagainstnetworkorportfailures.Thefinalstepinmakingyourwhole

environmentfailureresistantistoprotectagainstserverfailure.ESXServersystems

failoveroptionsarediscussedinthefollowingsections.

Using VMware HA

VMwareHAallowsyoutoorganizevirtualmachinesintofailovergroups.Whenahost

fails,allitsvirtualmachinesareimmediatelystartedondifferenthosts.Whenavirtualmachineisrestoredonadifferenthost,itlosesitsmemorystatebutitsdiskstateis

exactlyasitwaswhenthehostfailed(crashconsistentfailover).Sharedstorage(such

asaSAN)isrequiredforHA.SeetheResourceManagementGuide.

Server Failover and Storage Considerations

Foreachtypeofserverfailover,youmustconsiderstorageissues:

Approachestoserverfailoverworkonlyifeachserverhasaccesstothesame

storage.Becausemultipleserversrequirealotofdiskspace,andbecausefailover

forthestoragesystemcomplementsfailoverfortheserver,SANsareusually

employedinconjunctionwithserverfailover.

WhenyoudesignaSANtoworkinconjunctionwithserverfailover,allvolumes

theclusteredvirtualmachinesusemustbeseenbyallESXServerhosts.

Althoughavolumeisaccessibletoahost,allvirtualmachinesonthathostdonot

necessarilyhaveaccesstoalldataonthatvolume.Avirtualmachinecanaccess

onlythevirtualdisksforwhichitwasconfigured.Incaseofaconfigurationerror,

virtualdisksarelockedwhenthevirtualmachinebootssonocorruptionoccurs.

NOTE YoumustbelicensedtouseVMwareHA.

NOTE Asarule,whenyourebootingfromaSAN,eachbootvolumeshouldbeseen

onlybytheESXServersystemthatisbootingfromthatvolume.Anexceptioniswhen

youretryingtorecoverfromafailurebypointingasecondESXServersystemtothe

samevolume.Inthiscase,theSANvolumeinquestionisnotreallyforbootingfroma

SAN.NoESXServersystemisbootingfromitbecauseitiscorrupted.TheSANvolume

isaregularnonbootvolumethatismadevisibletoanESXServersystem.


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Chapter 2 Installation of iSCSI Initiators and Storage

Recommendations


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VMware, Inc. 39

Recommendations

Considerthefollowingrecommendationswhenyousetupyourenvironmentwith

ESX ServerhostsandaSAN:

Userawdevicemappingforavirtualdiskofavirtualmachinetousesomeofthe

hardwaresnapshottingfunctionsofthestoragesystem,ortoaccessadiskfrom

bothavirtualmachineandaphysicalmachineinacoldstandbyhost

configurationfordataLUNs.

TouseVMotiontomoveavirtualmachinetoadifferenthost,theLUNsthathold

thevirtualdisksofthevirtualmachinesmustbevisiblefromallofthehosts.

Setting LUN Allocations

WhenyousetLUNallocations,notethefollowingpoints:

StorageProvisioning.ToensurethattheESXServersystemrecognizestheLUNs

atstartuptime,provisionallLUNStotheappropriateHBAsbeforeconnectingthe

SANtotheESXServersystem.

VMotionandVMwareDRS.WhenyouuseVirtualCenterandVMotionorDRS,

makesurethattheLUNsforthevirtualmachinesareprovisionedtoallESXServer

hosts.Thisconfigurationprovidesthegreatestfreedominmovingvirtual

machines.

Activeactiveversusactivepassivearrays.WhenyouuseVMotionorDRSwith

anactivepassiveSANstoragedevice,makesurethatallESXServersystemshave

consistentpathstoallstorageprocessors.Notdoingsocancausepaththrashing

whenaVMotionmigrationoccurs.SeeResolvingPathThrashingonpage 109.

ForactivepassivestoragearraysnotlistedintheStorage/SANCompatibilityGuide,

VMwaredoesnotsupportstorageportfailover.Youmustconnecttheservertothe

activeportonthestoragesystem.ThisconfigurationensuresthattheLUNsarepresentedtotheESXServerhost.

NOTE VMwarerecommendsthatyouprovisionallLUNstoallESXServerHBAs

atthesametime.HBAfailoverworksonlyifallHBAsseethesameLUNs.


Setting Up Hardware iSCSI Initiators and Storage


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40 VMware, Inc.

Setting Up Hardware iSCSI Initiators and Storage

WithhardwarebasediSCSIstorage,youuseaspecializedthirdpartyadaptercapable

ofaccessingiSCSIstorageoverTCP/IP.ThisiSCSIinitiatorhandlesalliSCSIprocessing

andmanagementforyourESXServersystem.

HardwareiSCSIinitiatorsrequireconfigurationtoworkproperly,soyoumustinstall

andconfigurethehardwareiSCSIinitiatorsasdetailedinthefollowingsectionsbefore

settingupthedatastorethatresidesonaniSCSIstoragedevice.

Installing and Viewing Hardware iSCSI Initiators

Forinformationonwhichinitiatorsaresupported,seetheI/OCompatibilityGuideonthe

VMwareWebsiteatwww.vmware.com.

BeforeyoubeginconfiguringthehardwareiSCSIinitiator,makesurethattheiSCSI

HBAissuccessfullyinstalledandappearsonthelistofinitiatorsavailablefor

configuration.Iftheinitiatorisinstalled,youcanviewitsproperties.

To view the hardware iSCSI initiator properties

1 LogintotheVIClientandselectaserverfromtheinventorypanel.

2 ClicktheConfigurationtabandclickStorageAdaptersintheHardwaregroup.

Thelistofavailablestorageadapters(initiators)appears.TheiSCSIinitiatorappearsinthelistofstorageadapters.

3 UnderHBA,choosetheinitiatortoconfigure.

Thedetailsfortheinitiatorappear,includingthemodel,IPaddress,iSCSIname,

discoverymethods,iSCSIalias,andanydiscoveredtargets.

NOTE YoucanconfiguresomeESXServersystemstoloadbalancetrafficacross

multipleHBAstomultipleLUNswithcertainactiveactivearrays.Todothis,assign

preferredpathstoyourLUNssothatyourHBAsarebeingusedevenly.


4 Click Properties.
http://www.vmware.com/http://www.vmware.com/


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VMware, Inc. 41

4 ClickProperties.

TheiSCSIInitiatorPropertiesdialogboxappears.TheGeneraltabdisplays

additionalcharacteristicsoftheinitiator.

Youcannowconfigureyourhardwareinitiatororchangeitsdefaultcharacteristics.

Configuring Hardware iSCSI Initiators

WhenyouconfigurethehardwareiSCSIinitiator,setupyourinitiatorsiSCSIname,

IP address,anddiscoveryaddresses.VMwarerecommendsthatyousetupCHAP

parametersalso.

AfteryouconfigureyourhardwareiSCSIinitiator,performarescansothatallLUNs

thattheinitiatorhasaccesstoappearonthelistofstoragedevicesavailabletoyourESX Serverhost.

Setting up Naming Parameters

WhenyouconfigureyourhardwareiSCSIinitiators,makesurethattheirnamesand

IP addressesareformattedproperly.SeeiSCSINamingConventionsonpage 19.


To set up the iSCSI name, alias, and IP address for the hardware initiator


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42 VMware, Inc.

p

1 OpentheiSCSIInitiatorPropertiesdialogboxbyperformingthestepslistedin

ToviewthehardwareiSCSIinitiatorpropertiesonpage 40.

2 ClickConfigure.

TheGeneralPropertiesdialogboxappears.

3 TochangethedefaultiSCSInameforyourinitiator,enterthenewname.

Formatthenameyouenterproperly;otherwise,somestoragedevicesmightnot

recognizethehardwareiSCSIinitiator.Youcanusethedefaultnamesuppliedby

thevendor.Itdoesnothavetobechanged.

4 EntertheiSCSIalias.

ThealiasisanamethatyouusetoidentifythehardwareiSCSIinitiator.

5 Ifyou

selected

Use

the

following

IP

settings,

enter

values

for

the

following:

IPAddress

SubnetMask

DefaultGateway

6 ClickOKtosaveyourchanges,thenreboottheserverforthechangestotakeeffect.


Setting Up Discovery Addresses for the Hardware Initiator


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VMware, Inc. 43

Setuptargetdiscoveryaddressessothatthehardwareinitiatorcandeterminewhich

storageresourceonthenetworkisavailableforaccess.Youcandothiswitheither

dynamicdiscovery,wherealltargetsassociatedwithanIPaddressarediscovered,orwithstaticdiscovery,whereyoumustspecifytheIPaddressandtheiSCSInameofthe

targettobeseen.

To set up target discovery addresses using Dynamic Discovery


ToviewthehardwareiSCSIinitiatorpropertiesonpage 40.

2 IntheiSCSIInitiatorPropertiesdialogbox,clicktheDynamicDiscoverytab.


3 ToaddanewiSCSItargetthatyourESXServerhostcanuseforaSendTargets


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44 VMware, Inc.

session,clickAdd.

TheAddSendTargetsServerdialogboxappears.

4 EntertheIPaddressofastoragesystemandclickOK.

AfteryourESXServerhostestablishestheSendTargetssessionwiththistarget

device,anynewlydiscoveredtargetsappearintheStaticDiscoverylist.

5 TochangeordeleteaspecificIPaddress,selectitandclickEditorRemove.

To set up target discovery addresses by using Static Discovery

1 OpentheiSCSIInitiatorPropertiesdialogboxbyperformingthestepslistedinTo

viewthehardwareiSCSIinitiatorpropertiesonpage 40.

2 IntheiSCSIInitiatorPropertiesdialogbox,clicktheStaticDiscoverytab.


Thetabdisplaysalldynamicallydiscoveredtargetsandanystatictargetsalready

d


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VMware, Inc. 45

entered.

3 ToaddatargetaccessibletoyourESXServerhost,clickAddandenterthetargets

IPaddressandfullyqualifieddomainname.

4 Tochangeordeleteaspecificdynamicallydiscoveredtarget,selectthetargetand

clickEditorRemove.

NOTE Ifyouremoveadynamicallydiscoveredstatictarget,thetargetcanbe

returnedtothelistthenexttimearescanhappens,theHBAisreset,orthesystem

isrebooted.


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3 TomakeanychangestotheexistingCHAPparameters,clickConfigure.


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TheCHAPAuthenticationdialogboxopens.

4 TokeepCHAPenabled,selectUsethefollowingCHAPcredentials.

5 EitherenteranewCHAPnameorselectUseinitiatorname.

6 Ifneeded,specifytheCHAPSecret.

AllnewtargetswillusetheCHAPsecrettoauthenticatetheinitiator.

7 ClickOKtosavechanges.

Adding Hardware-Initiated iSCSI Storage

WhenyoucreateadatastoreonahardwareinitiatediSCSIstoragedevice,theAdd

Storagewizardguidesyouthroughtheconfiguration.

To create a datastore on a hardware-initiated iSCSI device


2 ClicktheConfigurationtabandclickStorage.

3 ClickAddStorage.

NOTE IfyoudisableCHAP,existingsessionsremainuntilarebootorthestorage

systemforcesalogout,thenyoucannotconnecttotargetsthatrequireCHAP.


TheSelectStorageTypepageappears.


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4 SelectDisk/LUN,andclickNext.

TheSelectDisk/LUNpageappears.Thiscantakeafewsecondsdependingonthe

numberoftargetsthatyouhave.


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Setting Additional Parameters

Y h f h i i ili fi ddi i l f


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Youcanusetheesxcfg-hwiscsiutilitytoconfigureadditionalparametersforyour

hardwareiSCSIHBA.Forexample,someiSCSIstoragesystemsrequireARP

redirectiontomoveiSCSItrafficdynamicallyfromoneporttoanother.YoumustallowARPredirectiononyourhardwareiSCSIHBA.

SeeAppendix B,Utilities,onpage 123.

Setting Up Software iSCSI Initiators and Storage

WiththesoftwarebasediSCSIimplementation,youcanuseastandardnetwork

adaptertoconnectyourESXServersystemtoaremoteiSCSItargetontheIPnetwork.

TheESXServersoftwareiSCSIinitiatorbuiltintoVMkernelfacilitatesthisconnection

communicatingwiththenetworkadapterthroughthenetworkstack.

BeforeyouconfiguredatastoresthatuseasoftwareinitiatediSCSIconnectiontoaccess

theiSCSIstorage,youmustenablenetworkconnectivityandtheninstallandconfigure

thesoftwareiSCSIinitiator.

Networking Configuration for Software iSCSI Storage

BeforeyoucanconfigureiSCSIstorage,youmustcreateaVMkernelporttohandle

iSCSInetworkingand(forESXServer3only)aserviceconsoleconnectiontotheiSCSI

network.

To create a VMkernel port for software iSCSI

1 LogintotheVI Clientandselecttheserverfromtheinventorypanel.

Thehardwareconfigurationpageforthisserverappears.

2 Clickthe

Configuration

tab

and

click

Networking.

CAUTION IfyouareconfiguringasoftwareiSCSIimplementationwithESXServer3,

youmust

set

up

both

the

VMkernel

port

and

the

service

console

connection

in

your

networkingconfiguration.


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VLANIDIdentifiestheVLANthattheportgroupsnetworktrafficwilluse.

VLANIDsarenotrequired.Ifyouarenotsurewhetheryouneedthem,askyour

t k d i i t t


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networkadministrator.

9 Youreceiveawarningthatnodefaultgatewayisset.Agatewayisneededfor

connectivitytomachinesnotonthesameIPsubnetastheserviceconsole

(ESX Server3only)orVMkernel.Toconnecttomultiplesubnets,clickYesto

configure

one.


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4 OnthePortstab,clickAdd.

TheAddNetworkWizardappears.


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5 Asaconnectiontype,selectServiceConsoleandclickNext.

TheConnectionSettingspageappears.

6 InthePortGroupPropertiesarea,enteranetworklabelthatidentifiestheport

groupthat

you

are

creating.

NewerportsandportgroupsappearatthetopofthevSwitchdiagram.


7 EntertheIPAddressandSubnetMask,orselecttheObtainIPsetting

automaticallyDHCPoptionfortheIPaddressandsubnetmask.Thismustbea

different IP address than the one chosen for the VMkernel.


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differentIPaddressthantheonechosenfortheVMkernel.

8 ClickEdit

to

set

the

Service

Console

Default

Gateway.

9 ClickNext.

TheReadytoCompletepageappears.

10 AfteryouhavedeterminedthatthevSwitchisconfiguredcorrectly,clickFinish.

AfteryoucreateaVMkernelportandserviceconsoleconnection,youcanenable

andconfiguresoftwareiSCSIstorage.

Configuring Software iSCSI Initiators

ToconfigurethesoftwareiSCSIinitiator,youenableitandsetupitstargetaddresses.VMwarerecommendsthatyoualsosetupitsCHAPparameters.

AfteryouconfigureyoursoftwareiSCSIinitiator,performarescan,sothatallLUNs

thattheinitiatorhasaccesstoappearonthelistofstoragedevicesavailabletoyour

ESX Serversystem.


Enabling Software iSCSI Initiators

EnableyoursoftwareiSCSIinitiatorsothatESXServercanuseit.


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To enable the software iSCSI initiator1 OpentheiSCSIInitiatorPropertiesdialogboxbyperformingthestepslistedin

ToviewthesoftwareiSCSIinitiatorpropertiesonpage 60.

2 ClickConfigure.

TheGeneralPropertiesdialogboxopens,displayingtheinitiatorsstatus,default

name,andalias.

3 Toenabletheinitiator,selectEnabled.

4 TochangethedefaultiSCSInameforyourinitiator,enterthenewname.

You do notneedtochangethedefaultname.

Formatthenameyouenterproperly;otherwise,somestoragedevicesmightnotrecognizethesoftwareiSCSIinitiator.

5 ClickOKtosaveyourchanges.


Setting up Discovery Addresses

Setuptargetdiscoveryaddressessothatthesoftwareinitiatorcandeterminewhich

storage resource on the network is available for access


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storageresourceonthenetworkisavailableforaccess.

To set up target discovery addresses for the software initiator



2 ClicktheDynamicDiscoverytab.

3 Toadd

anew

iSCSI

target

your

ESX

Server

host

can

use

for

aSendTargets

session,

clickAdd.

TheAddSendTargetsServerdialogboxappears.

4 EntertheSendTargetsserverIPaddressandclickOK.

5 TochangeordeleteaSendTargetsserver,selecttheserverandclickEditor

Remove.


Setting up CHAP Parameters

WhenyouconfigureyoursoftwareiSCSIinitiator,ensurethatCHAPconfiguration

matches your iSCSI storage If CHAP is enabled on the storage it must be enabled on


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matchesyouriSCSIstorage.IfCHAPisenabledonthestorage,itmustbeenabledon

theinitiator.

If

they

are

enabled,

you

must

set

up

the

CHAP

authentication

credentials

tomatchyouriSCSIstorage.

To set up CHAP parameters for the software initiator



2 ClicktheCHAPAuthenticationtab.

ThetabdisplaysthedefaultCHAPparameters.

3 TomakeanychangestotheexistingCHAPparameters,clickConfigure.


TheCHAPAuthentication dialogboxopens.


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4 TokeepCHAPenabled,selectUsethefollowingCHAPcredentials.

5 EitherenteranewCHAPnameorselectUseinitiatorname.

6 Ifneeded,specifytheCHAPSecret.

AllnewtargetswillusetheCHAPsecrettoauthenticatetheinitiator.

Any establishedsessionsarenotaffected.

7 ClickOKtosavechanges.

Viewing Software iSCSI InitiatorsThesoftwareiSCSIinitiatorthatyourESXServersystemusestoaccessa

softwareinitiatediSCSIstoragedeviceappearsonthelistofavailableadapters.

After configuringyoursoftwareinitiator,youcanusetheVIClienttoreviewits

properties.

To view the software iSCSI initiator properties


2 ClicktheConfigurationtabandclickStorageAdaptersunderhardware.

Thelistofavailablestorageadaptersappears.

3 UnderiSCSISoftwareAdapter,choosetheavailablesoftwareinitiator.

NOTE IfyoudisableCHAP,existingsessionsremainuntilarebootorthestorage

systemforcesalogout,youcannotconnecttotargetsthatrequireCHAP.


Thedetailsfortheinitiatorappear,includingthemodel,IPaddress,iSCSIname,

discoverymethods,iSCSIalias,andanydiscoveredtargets.


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4 ClickProperties.

TheiSCSIInitiatorPropertiesdialogboxopens.TheGeneraltabdisplays

additionalcharacteristicsofthesoftwareinitiator.


Adding Software-Initiated iSCSI Storage

WhenyoucreateadatastoreonasoftwareinitiatediSCSIstoragedevice,theAdd

Storagewizardguidesyouthroughtheconfiguration.


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g g y g g

To create a datastore on a software-initiated iSCSI device


2 ClicktheConfigurationtabandclickStorage.

3 ClickAddStorage.

TheSelectStorageTypepageappears.

4 SelecttheDisk/LUNstoragetypeandclickNext.


TheSelectDisk/LUNpageappears.Thiscantakeafewsecondsdependingonthe

numberoftargetsthatyouhave.


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5 SelecttheiSCSIdevicetouseforyourdatastoreandclickNext.

TheCurrentDiskLayoutpageappears.

6 LookoverthecurrentdisklayoutandclickNext.

TheDisk/LUNProperties

page

appears.

7 Enteradatastorename.

ThedatastorenameappearsintheVIClient,andthelabelmustbeuniquewithin

thecurrentVirtualInfrastructureinstance.

8 ClickNext.


TheDisk/LUNFormattingpageappears.


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9 Ifneeded,adjustthefilesystemvaluesandcapacityyouuseforthedatastore.

Bydefault,theentirefreespaceavailableonthestoragedeviceisofferedtoyou.

10 ClickNext.

TheReadytoCompletepageappears.

11 ReviewthedatastoreconfigurationinformationandclickFinish.

ThiscreatesthedatastoreonthesoftwareinitiatediSCSIstoragedevice.

3


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AfteryouinstallyouriSCSIinitiatorsandstorage,youmightneedtomodifyyour

storagesystemtoensurethatitworksproperlywithyourESXServerimplementation.

ThischapterdiscussesmanyoftheiSCSIstoragesystemssupportedinconjunction

withVMwareESXServer.Foreachdevice,itlistsmajorknownpotentialissues,points

tovendorspecificinformation(ifavailable),orincludesinformationfromVMwareknowledgebasearticles.


SetupOverviewonpage 66

GeneralConsiderationsonpage 66

EMCCLARiiONStorageSystemsonpage 67

EMCSymmetrixStorageSystemsonpage 68

HPStorageWorksStorageSystemsonpage 69

NetworkApplianceStorageSystemsonpage 71

EqualLogicStorageSystemsonpage 74

LeftHandNetworksSAN/iQStorageSystemsonpage 75

Modifying SAN Storage

Systems with ESX Server 3

NOTE Informationinthisdocumentisupdatedonlywitheachrelease.New

informationmightalreadybeavailable.Also,otheriSCSIstoragesystemsare

supportedbutarenotcoveredinthischapter.ConsultthemostrecentStorage/SAN

CompatibilityGuide,checkwithyourstoragevendor,andexploretheVMware

knowledgebase

articles.


Setup Overview

VMwareESXServersupportsavarietyofSANstoragesystemsindifferent

configurations.Notallstoragedevicesarecertifiedforallfeaturesandcapabilitiesof


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ESXServer,andvendorsmighthavespecificpositionsofsupportwithregardtoESX Server.Forthelatestinformationregardingsupportedstoragesystems,seethe

Storage/SANCompatibilityGuide.

VMwaretestsESXServerwithstoragesystemsinthefollowingconfigurations:

Basic Connectivity. TestswhetherESXServercanrecognizeandoperatewiththe

storagesystem.Thisconfigurationdoesnotallowformultipathingoranytypeof

failover.

HBA Failover. TheserverisequippedwithmultipleHBAsconnectingtooneormore

SANswitches.TheserverisrobusttoHBAandswitchfailureonly.

Storage Port Failover. Theserverisattachedtomultiplestorageportsandisrobust

tostorageportfailuresandswitchfailures.

Booting from a SAN. TheESXServerhostbootsfromaLUNconfiguredontheSAN

ratherthan

from

the

server

itself.

General Considerations

Forallstoragesystems,makesurethatthefollowingrequirementsaremet:

LUNsmustbepresentedtoeachHBAofeachhostwiththesameLUNIDnumber.

Ifdifferentnumbersareused,theESXServerhostsdonotrecognizedifferent

pathstothesameLUN.BecauseinstructionsonhowtoconfigureidenticalSANLUNIDsarevendorspecific,consultyourstoragedocumentationformore

information.

Unlessspecifiedforindividualstoragesystemsdiscussedinthischapter,setthe

hosttypeforLUNspresentedtoESXServertoLinuxorLinux Cluster,if

applicabletoyourstoragesystem.ThemethodESXServerusestoaccessthe

storagesystemismostcompatiblewithLinuxaccess,however,thiscanvary

dependingonthestoragesystemyouareusing.

Chapter 3 Modifying SAN Storage Systems with ESX Server

IfyouareusingVMotion,DRS,orHA,makesurethatsourceandtargethostsfor

virtualmachinescanseethesameLUNswithidenticalLUNIDs.

SAN administratorsmightfinditcounterintuitivetohavemultiplehostsseethe

sameLUNsbecausetheymightbeconcernedaboutdatacorruption.However,


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VMFSpreventsmultiplevirtualmachinesfromwritingtothesamefileatthesametime,soprovisioningtheLUNstoallrequiredESXServersystemisappropriate.

IfyoudonothaveCHAPauthenticationsetupontheLUNsthatarebeing

accessed,youmustalsodisableCHAPontheESXServerhost.Otherwise,

authenticationofthestoragesystemfails,althoughtheLUNshavenoCHAP

requirement.

EMC CLARiiON Storage Systems

EMCCLARiiONstoragesystemsworkwithESXServermachinesinSAN

configurations.Basicconfigurationstepsinclude:

1 Installingandconfiguringthestoragedevice.

2 CreatingRAIDgroups.

3 CreatingandbindingLUNs.

4 RegisteringtheserversconnectedtotheSAN.

5 CreatingstoragegroupsthatcontaintheserversandLUNs.

UsetheEMCsoftwaretoperformconfiguration.Formoreinformation,seetheEMC

documentation.

Toavoidthepossibilityofpaththrashing,thedefaultmultipathingpolicyisMost

RecentlyUsed,notFixed.TheESXServersystemsetsthedefaultpolicywhenit

identifiesthestoragesystem.SeeResolvingPathThrashingonpage 109.

AutomaticvolumeresignaturingisnotsupportedforAX100iandAX150istorage

devices.Forinformationonresignaturing,seeVMFSVolumeResignaturingon

page 117.

NOTE Thisisanactivepassivediskarray,sorelatedissuesdescribedelsewhereinthis

documentapply.

NOTE TobootfromaSAN,choosetheactivestorageprocessorforthebootLUNs

targetintheHBABIOS.


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Chapter 3 Modifying SAN Storage Systems with ESX Server

HP StorageWorks Storage Systems

ThissectionincludesconfigurationinformationforHPStorageWorksstoragesystems.

Foradditionalinformation,seethesectiononVMwareESXServeratthe


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HP ActiveAnswersWebsite.

HP StorageWorks MSA

Thissectiondescribesthesetupandconfigurationstepsneededtoallowan

HP StorageWorksMSA1510istoragesystemtocommunicatewithinanESX Server

environment.

To enable MSA1510i storage systems to communicate with ESX Server

1 Install,connect,andpowerupthenetworkdevicesasdetailedinthevendorinstallationdocument.

2 ObtaintheIPaddressassignedtotheMSA1510icontrollermanagementport.

a ScrollthroughthemessagesontheLCDpaneluntilthefollowingmessage

appears:603

Port

MA0

IP

b RecordthemanagementportIPaddressthatappearsinBasicMSA1510i

information.

3 FromtheserveroraworkstationontheMSA1510iLANsegment,openaWeb

browserandentertheaddressobtainedinStep 2.

4 Whenprompted,enterthefollowingdefaultaccesspermissions:

Username:root

Password:root

5 Whenprompted,setauniqueusernameandpassword.

6 Usingthewizard,completethefollowingactions:

a Storageconfiguration

i SettheFaultTolerantmode(RAIDmode).

ii AssignasparediskforappropriateRAIDlevel.

b iSCSIconfiguration(configureaniSCSIportal)

i Selectadataport.

ii AssignanIPaddresstothedataport.


iii VLANsaresetupontheswitchandareusedasonemethodofcontrollingaccesstothestorage.IfyouareusingVLANs,entertheVLANIDtouse(0=notused).

iv ThewizardsuggestsadefaultiSCSITargetNameandiSCSITargetAlias.


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Acceptthedefaultorenteruserdefinedvalues.

c LoginSettings

d ManagementSettings

7 ClickFinishtoapplytheconfigurationsettings.

Afterinitialsetup,performthefollowingtaskstocompletetheconfiguration:

Createanarray.

Createalogicaldrive.

Createatarget.

Createaportalgroup.

Associate

or

assign

the

portals

created

using

the

wizard

with

the

portal

group

created.

Maplogicaldrivestothetarget.

Addinitiators(initiatorIQNnameandalias).

UpdatetheACLsofthelogicaldrivestoprovideaccesstoinitiators(selectthelist

ofinitiatorstoaccessthelogicaldrive).

SeetheMSA1510i

Configuration

Guide.

NOTE Toconfiguretheremainingdataports,completetheInitialSystem

ConfigurationWizardprocess,andthenusetasksavailableonthe

Configuretab.

NOTE Wizardsareavailableforbasicconfigurationtasksonly.UsetheManageand

Configuretabstoviewandchangeyourconfiguration.


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Setting LUN Type and Initiator Group Type

SettheappropriateLUNtypeandinitiatorgrouptypeforthestoragesystem:

LUNtypeVMware(ifVMwaretypeisnotavailable,useLinux).


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InitiatorgrouptypeVMware(ifVMwaretypeisnotavailable,useLinux).

Provisioning Storage

Youmustprovisionstorage,usingeitherFilerVieworCLI.

To provision storage by using FilerView storage management

1 LogintoNetworkAppliancestoragesystemmanagement(FilerView).

2 Createavolume.

a SelectVolumesandclickAdd.ClickNext.

b SelectFlexibility(Default)orTraditional,thenclickNext.

c Enter

a

Volume

Name,

select

a

Language,

and

click

Next.

d EntervaluesforContainingAggregate,TotalVolumeSize,andSpace

GuaranteeandclickNext.

e ClickCommittocreatethevolume.

3 CreateLUNs.

a SelectLUNsandclickAdd.

b Enterthefollowing:

i Path:Enterapath,forexample,/vol/vol1/lun1.

ii LUNProtocolType:VMware.

iii Description:Abriefdescription.

iv SizeandUnit:Enterasize,forexample,10GBandselectSpaceReserved.

4 Createaninitiatorgroup.

a SelectLUNs>InitiatorGroupandclickAdd.

b Enterthefollowing:

i GroupName:Enteragroupname

ii Type:ChooseiSCSI.


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ForadditionalinformationonusingNetworkApplianceStoragewithVMware

technology,seethefollowingNetworkAppliancedocuments:

NetworkAppliance&VMwareESXServer:InstantaneousBackup&Recovery

with

NetApp

Snapshot

Technology

at

http://www.netapp.com/library/tr/3428.pdf.
http://www.netapp.com/library/tr/3428.pdfhttp://www.netapp.com/library/tr/3428.pdf


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pp p gy p // pp / y/ / p TechnicalCaseStudy:UsingaNetworkApplianceSANwithVMwaretoFacilitate

StorageandServerConsolidationathttp://www.netapp.com/library/tr/3401.pdf.

EqualLogic Storage Systems

TosetupyourEqualLogicstoragesystemstoworkinanESXServerimplementation,

youmust

address

the

following

issues:

Multipathing. NospecialsetupisneededbecauseEqualLogicstoragesystemssupport

storageproccesorfailoverthatistransparenttoiSCSI.MultipleiSCSIHBAsor

NICscanconnecttothesametargetorLUNonthestorageside.However,normal

restrictionsonESXServerconfigurationapply,forexampleNICteamingmustbe

correctlysetup.

Creating iSCSI LUNs. FromtheEqualLogicwebportal,rightclickVolumes,and

thenselectCreateVolume.

Enable ARP redirection on hardware iSCSI HBAs. Formoreinformationon

enablingARPredirection,seeesxcfghwiscsiUtilityonpage 126.

FormoreinformationaboutconfiguringandusingEqualLogicstoragesystems,seethe

vendorsdocumentation.

NOTE YoumustaddtheserviceconsoleandVMkernelIPaddressesbeingusedfor

iSCSIaccesstotheIPaddressACLonyourEqualLogicstoragesystems.Ifyouare

usingCHAPauthenticationorinitiatornamebasedACLs,however,thisisnot

necessary.
http://www.netapp.com/library/tr/3428.pdfhttp://www.netapp.com/library/tr/3401.pdfhttp://www.netapp.com/library/tr/3401.pdf


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Chapter 4 Booting from a SAN with ESX Server Systems

Enabling Booting from a SAN

EnablingyourESXServerhosttobootfromaSANrequiresthecompletionofanumber

oftasks.

To enable booting from a SAN


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1 Reviewanyvendorconfigurationrecommendationsthatapplytothestorage

systemortheserverbootingfromSAN.

2 Configurethehardwareelementsofyourstoragenetwork,including:

SANseePreparingtheSANonpage 79.

HBAsseeConfiguringiSCSIHBAstoBootfromaSANonpage 81

3 ConfigureACLsonyourstoragesystem.

ProperaccesscontrolonthestoragesystemsisimportantwhenanESXServerhost

isbootingfromiSCSI.

BootLUNsshouldonlybevisibletotheserverusingthatLUNtoboot.No

otherserverorsystemontheSANshouldbepermittedtoseethatbootLUN.

MultipleESXServerhostscanshareadiagnosticpartition.ACLsonthe

storagesystemscanallowyoutodothis.

4 Choosethelocationforthediagnosticpartition.

DiagnosticpartitionscanbeputonthesameLUNasthebootpartition.Core

dumpsarestoredindiagnosticpartitions.

5 SetupyourESXServertobootfromCDROMfirstbecausetheVMwareinstallationCDisintheCDROMdrive.

Toachievethis,changethesystembootsequenceinyoursystemBIOSsetup.

Preparing the SAN

BeforeyouconfiguretheiSCSIHBAstobootfromaSAN,firstprepareyourstorage

areanetwork

by

checking

the

cabling

and

switch

wiring

and

configuring

the

storage

system.


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Configuring iSCSI HBAs to Boot from a SAN

ThissectiondiscusseshowtoconfigureaQLogiciSCSIHBAforbootingfromaSAN.

OnasystemsetuptobootfromaSAN:

ThesystemBIOSmustdesignatetheiSCSIcardasthebootcontroller.


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TheBIOSmustbeenabledontheiSCSIHBAtolocatethetargetbootLUN.

To enable the QLogic iSCSI HBA to Boot from a SAN

1 DuringserverPOST,pressCrtl+qtoentertheQLogiciSCSIHBAconfiguration

menu.

2 SelecttheI/Oporttoconfigure.

Bydefault,theAdapterBootmodeissettoDisable.

3 ConfiguretheHBA.

a FromtheFast!UTILOptionsmenu,selectConfiguration

Settings>Host

AdapterSettings.

b Configurethefollowingsettingsforyourhostadapter:initiatorIP address,

subnetmask,gateway,initiatoriSCSIname,andCHAP(ifrequired).


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d FromtheiSCSIBootSettingsmenu,selecttheprimarybootdevice.Anauto

rescanoftheHBAismadetofindnewtargetLUNS.

e SelecttheiSCSItarget.

NOTE IfmorethenoneLUNexistswithinthetarget,youcanchooseaspecific

LUNIDbypressingEnterafteryoulocatetheiSCSIdevice.


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Managing ESX Server

5


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ThischaptercanhelpyoumanageyourESXServersystem,useSANstorageeffectively,

andperformtroubleshooting.


Issuesand

Solutions

on

page 86

GettingInformationonpage 87

ResolvingDisplayIssuesonpage 89

AdvancedLUNDisplayConfigurationonpage 92

Multipathingonpage 94

PathFailover

on

page 101

VMkernelConfigurationonpage 102

AvoidingandResolvingSANProblemsonpage 103

OptimizingSANStoragePerformanceonpage 103

ResolvingPerformanceIssuesonpage 108

SANStorageBackupConsiderationsonpage 113

LayeredApplicationsonpage 115

VMFSVolumeResignaturingonpage 117

Systems That Use SAN

Storage 5


Issues and Solutions

Table 51liststheissuesthataremostfrequentlyencounteredandeitherexplainshow

toresolvethemorpointstothelocationwheretheissueisdiscussed.

Table 5-1. Issues and Solutions

Issue Solution


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Guidelines for Avoiding SAN Problems

FollowtheseguidelinestoavoidpotentialproblemswithyourSANconfiguration:

PlaceonlyoneVMFSvolumeoneachLUN.MultipleVMFSvolumesononeLUN

isnotrecommended.

Donotchangethepathpolicythesystemsetsforyouunlessyouunderstandthe

implicationsofmakingsuchachange.Inparticular,workingwithan

activepassivearrayandsettingthepathpolicytoFixedcanleadtopaththrashing.

Issue Solution

ALUNisnotvisibleintheVIClient. SeeResolvingDisplayIssuesonpage 89.

Understandhowpathfailov

VMWARE Vi3!35!25 u2 Iscsi San Cfg

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