Spectra T950 - Page 75

Chapter 2 — Architecture Overview Fibre Channel Connectivity
November 2016 User Guide—Spectra T950 Library
75
IntheexampleshowninFigure38,theSCSIdrivesinthepartitionare
connectedtotheFibreChannelarbitratedlooporfabricthroughPortAof
theF‐QIPineachDBA.PortBofF‐QIP3alsoprovidesthepathoverwhich
SCSIcommandstocontroltheroboticsaresentfromthehost.
AsillustratedinFigure39,anF‐QIPprovidesany‐to‐anyconnectivityto
theSCSIdrivesitcontrols.Everydrive(target)ispotentiallyvisibleto
serversthroughbothportsontheF‐QIP.Thispermitsflexibilityin
configuringwhichservers canaccesswhichdrives(targetvisibility).
Forexample,aQIP‐basedpartitioncanbeconfiguredsothatDrive1and
Drive2are onlyaccessiblethroughPortAandDrive3andDrive4areonly
accessiblethroughPortB.Inthisconfiguration,Drive1andDrive2can
onlybeaccessedbythehostconnectedtoPortA;Drive3andDrive4can
onlybeaccessedbyahostconnected
toPortB.Inamorecomplex
configuration,theF‐QIPcanbeconfiguredsothatalldrivesarevisible
throughbothports.Suchaconfigurationistypicallyusedinashared
storageenvironmentoranenvironmentwithfailovercapabilities.
Figure 39 QIP-attached SCSI drive connectivity.
Drive 3
Drive 1 Drive 2
Internal cabling
Fiber port (Fibre Channel or Gigabit Ethernet)
QIP
Drive Bay Assembly (DBA)
Drive 4
Important
If drives are visible to multiple servers, your storage management software must
support this visibility. Otherwise server contention for a single drive can create
network and system problems.