HP StorageWorks X5500 Network Storage Gateway for Windows setup guide (AP809-96004, October 2009)

Chapter2:ConfigurationInformation 4
Fencing Requirements
Whencertainproblemsoccuronaserver(forexample,hardware
problemsorthelossofclusternetworkcommunications),andtheserver
ceasestoeffectivelycoordinateandcommunicatewithotherserversin
thecluster,HPClusteredFileSystemmustfencetheserver,removingits
accesstofilesystemstopreservedataintegrity.There
aretwofencing
methods:fabric‐basedfencing,whichdisablestheserver’saccessinthe
FCfabric,andwebmanagement‐basedfencing,whicheitherresetsor
shutsdowntheserver.Whenselectingafencingmethod,youshouldbe
awareofthefollowing:
•IfyouwillbeusingtheFibreChannelVirtualInterconnectmodules
on
theHPC‐ClassBladeSystem,youmustconfigurewebmangement‐
basedfencing.Fabric‐basedfencingcannotbeusedwiththese
modules.
•IfyouwillbeusingIPMIinterfaceswithwebmangement‐based
fencing,youwillneedtochangethepasswordfromthefactory
default.Thefencingfeaturewillnot
workcorrectlyifthepasswordis
notchanged.
• ISCSIstoragemustusewebmanagement‐basedfencing.
•Whentheclusterisconfiguredforfabric‐basedfencing,arraysmust
operateinfabricorswitch‐attachedmode(notarbitrated‐loop‐only
devices).Thisrequirementdoesnotapplyfornon‐fabricfencing
configurations.
•Withfabric‐based
fencing,iftheserversareconnectedtoswitchesin
multiplefabrics,thephysicalportsoneachswitchmustbeassignedto
uniquedomainIDs.AdifferentdomainIDmustbeusedoneach
fabric(anygivendomainIDcanexistononlyonefabricintheSAN).
Forexample,if
aserverisconnectedtotwoswitchesthatarenotinthe
samefabric,switch1couldusedomainID6andswitch2coulduse
domainID7.DomainID6mustnotexistonthefabriccontaining
switch2anddomainID7mustnotexistonthefabric containing
switch1.