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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:
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.
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iSCSI SAN Configuration Guide
Revision: 20090313Item: EN-000035-01
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VMware, Inc. 3
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
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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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VMware, Inc. 7
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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Intended Audience
TheinformationpresentedinthismanualiswrittenforexperiencedWindowsorLinux
systemadministratorswhoarefamiliarwithvirtualmachinetechnologydatacenteroperations.
Document Feedback
VMwarewelcomesyoursuggestionsforimprovingourdocumentation.Ifyouhave
comments,sendyourfeedbackto:
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/support7/29/2019 VMWARE Vi3!35!25 u2 Iscsi San Cfg
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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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iSCSI SAN Configuration Guide
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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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Chapter 1 Using ESX Server with a Storage Area Network
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
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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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Chapter 1 Using ESX Server with a Storage Area Network
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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Chapter 1 Using ESX Server with a Storage Area Network
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
iqn.199801.com.vmware.iscsi:name2
iqn.199801.com.vmware.iscsi:name999
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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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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Chapter 1 Using ESX Server with a Storage Area Network
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.
Chapter 1 Using ESX Server with a Storage Area Network
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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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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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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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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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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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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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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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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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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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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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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.
iSCSI SAN Configuration Guide
Setting Up Hardware iSCSI Initiators and Storage
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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.
Chapter 2 Installation of iSCSI Initiators and Storage
4 Click Properties.
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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.
iSCSI SAN Configuration Guide
To set up the iSCSI name, alias, and IP address for the hardware initiator
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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.
Chapter 2 Installation of iSCSI Initiators and Storage
Setting Up Discovery Addresses for the Hardware Initiator
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Setuptargetdiscoveryaddressessothatthehardwareinitiatorcandeterminewhich
storageresourceonthenetworkisavailableforaccess.Youcandothiswitheither
dynamicdiscovery,wherealltargetsassociatedwithanIPaddressarediscovered,orwithstaticdiscovery,whereyoumustspecifytheIPaddressandtheiSCSInameofthe
targettobeseen.
To set up target discovery addresses using Dynamic Discovery
1 OpentheiSCSIInitiatorPropertiesdialogboxbyperformingthestepslistedin
ToviewthehardwareiSCSIinitiatorpropertiesonpage 40.
2 IntheiSCSIInitiatorPropertiesdialogbox,clicktheDynamicDiscoverytab.
iSCSI SAN Configuration Guide
3 ToaddanewiSCSItargetthatyourESXServerhostcanuseforaSendTargets
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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.
Chapter 2 Installation of iSCSI Initiators and Storage
Thetabdisplaysalldynamicallydiscoveredtargetsandanystatictargetsalready
d
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entered.
3 ToaddatargetaccessibletoyourESXServerhost,clickAddandenterthetargets
IPaddressandfullyqualifieddomainname.
4 Tochangeordeleteaspecificdynamicallydiscoveredtarget,selectthetargetand
clickEditorRemove.
NOTE Ifyouremoveadynamicallydiscoveredstatictarget,thetargetcanbe
returnedtothelistthenexttimearescanhappens,theHBAisreset,orthesystem
isrebooted.
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Chapter 2 Installation of iSCSI Initiators and Storage
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
1 LogintotheVIClientandselectaserverfromtheinventorypanel.
2 ClicktheConfigurationtabandclickStorage.
3 ClickAddStorage.
NOTE IfyoudisableCHAP,existingsessionsremainuntilarebootorthestorage
systemforcesalogout,thenyoucannotconnecttotargetsthatrequireCHAP.
iSCSI SAN Configuration Guide
TheSelectStorageTypepageappears.
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4 SelectDisk/LUN,andclickNext.
TheSelectDisk/LUNpageappears.Thiscantakeafewsecondsdependingonthe
numberoftargetsthatyouhave.
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iSCSI SAN Configuration Guide
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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Chapter 2 Installation of iSCSI Initiators and Storage
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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Chapter 2 Installation of iSCSI Initiators and Storage
4 OnthePortstab,clickAdd.
TheAddNetworkWizardappears.
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5 Asaconnectiontype,selectServiceConsoleandclickNext.
TheConnectionSettingspageappears.
6 InthePortGroupPropertiesarea,enteranetworklabelthatidentifiestheport
groupthat
you
are
creating.
NewerportsandportgroupsappearatthetopofthevSwitchdiagram.
iSCSI SAN Configuration Guide
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.
Chapter 2 Installation of iSCSI Initiators and Storage
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.
iSCSI SAN Configuration Guide
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
1 OpentheiSCSIInitiatorPropertiesdialogboxbyperformingthestepslistedin
ToviewthesoftwareiSCSIinitiatorpropertiesonpage 60.
2 ClicktheDynamicDiscoverytab.
3 Toadd
anew
iSCSI
target
your
ESX
Server
host
can
use
for
aSendTargets
session,
clickAdd.
TheAddSendTargetsServerdialogboxappears.
4 EntertheSendTargetsserverIPaddressandclickOK.
5 TochangeordeleteaSendTargetsserver,selecttheserverandclickEditor
Remove.
Chapter 2 Installation of iSCSI Initiators and Storage
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
1 OpentheiSCSIInitiatorPropertiesdialogboxbyperformingthestepslistedin
ToviewthesoftwareiSCSIinitiatorpropertiesonpage 60.
2 ClicktheCHAPAuthenticationtab.
ThetabdisplaysthedefaultCHAPparameters.
3 TomakeanychangestotheexistingCHAPparameters,clickConfigure.
iSCSI SAN Configuration Guide
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
1 LogintotheVIClientandselectaserverfromtheinventorypanel.
2 ClicktheConfigurationtabandclickStorageAdaptersunderhardware.
Thelistofavailablestorageadaptersappears.
3 UnderiSCSISoftwareAdapter,choosetheavailablesoftwareinitiator.
NOTE IfyoudisableCHAP,existingsessionsremainuntilarebootorthestorage
systemforcesalogout,youcannotconnecttotargetsthatrequireCHAP.
Chapter 2 Installation of iSCSI Initiators and Storage
Thedetailsfortheinitiatorappear,includingthemodel,IPaddress,iSCSIname,
discoverymethods,iSCSIalias,andanydiscoveredtargets.
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4 ClickProperties.
TheiSCSIInitiatorPropertiesdialogboxopens.TheGeneraltabdisplays
additionalcharacteristicsofthesoftwareinitiator.
iSCSI SAN Configuration Guide
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
1 LogintotheVIClientandselectaserverfromtheinventorypanel.
2 ClicktheConfigurationtabandclickStorage.
3 ClickAddStorage.
TheSelectStorageTypepageappears.
4 SelecttheDisk/LUNstoragetypeandclickNext.
Chapter 2 Installation of iSCSI Initiators and Storage
TheSelectDisk/LUNpageappears.Thiscantakeafewsecondsdependingonthe
numberoftargetsthatyouhave.
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5 SelecttheiSCSIdevicetouseforyourdatastoreandclickNext.
TheCurrentDiskLayoutpageappears.
6 LookoverthecurrentdisklayoutandclickNext.
TheDisk/LUNProperties
page
appears.
7 Enteradatastorename.
ThedatastorenameappearsintheVIClient,andthelabelmustbeuniquewithin
thecurrentVirtualInfrastructureinstance.
8 ClickNext.
iSCSI SAN Configuration Guide
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.
Thischapterdiscussesthefollowingtopics:
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.
iSCSI SAN Configuration Guide
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.
iSCSI SAN Configuration Guide
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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iSCSI SAN Configuration Guide
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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iSCSI SAN Configuration Guide
ForadditionalinformationonusingNetworkApplianceStoragewithVMware
technology,seethefollowingNetworkAppliancedocuments:
NetworkAppliance&VMwareESXServer:InstantaneousBackup&Recovery
with
NetApp
Snapshot
Technology
at
http://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.
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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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Chapter 4 Booting from a SAN with ESX Server Systems
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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5\
Managing ESX Server
5
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ThischaptercanhelpyoumanageyourESXServersystem,useSANstorageeffectively,
andperformtroubleshooting.
Thischapterdiscussesthefollowingtopics:
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
iSCSI SAN Configuration Guide
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
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