Complete the Procedure
18
Drive Installation or Replacement Instructions 91010010
Overview Drivescanbedaisy‐chainedtogethertoaddmultipledrivestoa
partition.Ifyourlibraryconfigurationincludesdirect‐attachSCSIdrives
andyouplantodaisy‐chaintwoormoredrivesinaDBAonasingleSCSI
bus,youmustconnectthedrivesandthebusexpansionmodulebefore
youbeginconfiguringpartitions.ReadtheindividualUserGuidestolearn
moreaboutthebusexpansionmoduleandtheroleitplaysinthelibrary.
Note: Donotconnectthebusexpansionmoduletothehostuntilafter
youfinishconfiguringthepartitions.
Single SCSI BUS Configuration UptofourdrivesinasingleDBAcanbe
daisy‐chainedonasingleSCSIbus.Keepinmindthateachdriveincreases
thetotallengthoftheSCSIbus.DaisychainingallfourdrivesinaDBA
resultsinaninternalbuslengthofapproximately20feet(6meters),which
mustbesubtractedfromthemaximumallowedlengthof39feet(12
meters)foranLVDSCSIbus.
Note: Amaximumof16 devices,includingthefourdrivesinaDBA,
canbeconnectedtoasinglewideLVDSCSIbus.Attachingmore
thantwodevicestoasingleSCSIbuscanpotentiallyhavea
negativeimpactontheperformanceofalldevicesonthebus.
Figure 13illustratesdaisychainingall fourdrivesinaDBAonasingle
SCSIbusandconnectingthemtoonehost.
Figure 13 Daisy-chaining direct-attach SCSI drives in a DBA on a single SCSI bus.
Drive 3
Drive 1 Drive 2
Drive 4
Internal SCSI connection (DBA to drive)
Drive Bay Assembly
LVD SCSI cable
Internal SCSI connector (DBA to drive)
SCSI terminator
External SCSI connector (Bus expansion module or drive)
Bus expansion
module