Dell SC8000 - Front-End Connectivity Modes; Multipath IO; MPIO Behavior for Dual-Controller Storage Centers; MPIO Configuration Instructions for Servers

Chapter 4 Connect the Front End
96 Storage Center SC8000 Controller Deployment Guide
Multipath IO
MultipathIO(MPIO)allowsaservertousemultiplepathsforIOiftheyareavailable.
MPIOsoftwareoffersredundancyatthepathlevel.MPIOloadsasadriverontheserver,
andtypicallyoperatesinaround‐robinmannerbysendingpacketsfirstdownonepath
andthentheother.
Ifapathfails,MPIOsoftwarecontinuestosendpacketsdow nthe
functioningpath.MPIOisoperating‐systemspecific.
MPIO Behavior for Dual-Controller Storage Centers
WhenMPIOisconfigured,aservercansendIOtobothcontrollers.However,asingle
volumeisownedbyonecontrolleratatime.Evenifthereareactivepathsfromaserverto
bothcontrollers,IOforasinglevolumeisalwaysprocessedbyonecontroller.
Thislimitationonly applies
toindividualvolumes.Ifaserverhastwoormorevolumes
ownedbydifferentcontrollers,theservercansendIOtobothcontrollers.
MPIO Configuration Instructions for Servers
TouseMPIO,configureMPIOontheserverpriortoconnectingtheStorageCenterfront
end.Dependingontheoperatingsystem,thismayrequireinstallingMPIOsoftwareor
mayonlyrequiresettingserveroptions.
ToconfigureMPIOonaserver,seetheDellCompellentdocumentthatcorrespondstothe
serveroperating
system.
Front-End Connectivity Modes
StorageCenteruseseitherlegacymodeorvirtualportmodetotransportdatatoservers
thatuseSANstorage.Inlegacymode,front‐endIOportsareconfiguredinpairsofprimary
andreservedports.Invirtualportmode,allportsareactive,andifoneportfailstheload
is
distributedbetweentheremainingportswithinthesamefaultdomain.
Thefront‐endconnectivitymodeisconfiguredindependentlyforFibreChannelandiSCSI.
Bothtransporttypescanbeconfiguredtousethesamemodeordifferentmodestomeet
theneedsofthenetworkinfrastructure.Forexample,aStorageCenter
canbeconfigured
tousevirtualportmodeforFCandlegacymodeforiSCSI.
Operating System Document with MPIO Instructions
IBMAIX DellCompellentAIXBestPractices
Linux •DellCompellentStorageCenterLinuxBestPractices
•DellCompellentBestPractices:StorageCenterwithSUSELinux
EnterpriseServer11
VMwarevSphere5.x DellCompellentStorageCenterBestPracticeswithvSphere5.x
WindowsServer2003 StorageCenterMultipathIO(MPIO)ManagerforMicrosoftServersUser
Guide
WindowsServer
2008,2008
R2,and2012
DellCompellentStorageCenterMicrosoftMultipathIO(MPIO)Best
PracticesGuide
Note: InLegacymode,reserveportsandprimaryportsresideonseparate
controllers,providingcontroller‐levelfailoveronly.Legacymodedoesnotprovide
port‐levelfailover.