Why is the scsi bus type important, Internal drives, External drives – HP StoreEver Ultrium Tape Drives User Manual
Page 14: Removable drives
•
You will need a properly installed and configured SCSI host bus adapter (HBA) or a built-in
SCSI controller on your server and a suitably-rated SCSI cable. See also
Why is the SCSI bus
type important?
.
•
For optimum performance the drive should be the only device on the SCSI bus.
•
Always terminate the SCSI bus. Ultrium internal and removable tape drives require terminators;
external drives are auto terminating, as long as they are on a dedicated SCSI bus or the last
device on a chain.
•
Do not attach the drive to the same SCSI bus as your disk drive or to a RAID controller (unless you
are connecting to a ProLiant server with a Smart Array 6i RAID controller).
NOTE:
Always refer to
HBA running the recommended firmware version.
Internal drives
The tape drive is installed into a spare, industry-standard, 5¼-inch, full-height drive bay in your server
(or into an HP Rack-Mount Option Kit) and is attached to the SCSI bus of the host server. Use an
LVDS-compatible ribbon cable to connect the tape drive to a spare 68-pin, high density (HD), wide
SCSI connector on the host server. For most servers we recommend that you use the terminated SCSI
ribbon cable supplied with the drive.
See also
Installing an internal Ultrium tape drive
.
External drives
Your tape drive is supplied with a 68-pin, wide, VHD-to-HD SCSI cable to attach to the host server.
See also
Installing an external Ultrium tape drive
.
Check the usage models on
. This shows how the HP StorageWorks Ultrium tape drive can
be used in different system architectures.
Removable drives
The individual tape drives are connected to their host server via the high-density LVD/SE SCSI connectors
on the back of the tape array. They do not require any SCSI cables to plug into the tape array. However,
cabling and terminators are required to connect the tape array with the SCSI host. See also
removable Ultrium tape drive
.
Why is the SCSI bus type important?
The SCSI bus type determines the speed at which data can be transferred between devices on the bus
and the maximum length of cable that can be used. HP Ultrium 1840 and 960 drives support a burst
transfer rate of 320 MB/sec. HP Ultrium 460 drives support a burst transfer rate of 160 MB/sec. To
benefit from this level of performance, it is important to ensure that the drives are connected to a SCSI
bus of a similar or higher specification. This means that you need:
•
An Ultra320 bus for HP Ultrium 1840 and 960 drives. An Ultra160 or Ultra320 SCSI bus for
HP ultrium 460 drives. If you attach the drive to a lower specification SCSI bus, it may still
work but data will not be transferred as quickly.
•
LVD-rated SCSI cabling and terminators. The LVD interface enables the data to be transferred at
the drive’s maximum rate.
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Before you start