Scsi termination, Removable drives, Internal drives – HP StoreEver Ultrium Tape Drives User Manual
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Setting the SCSI ID on HP StorageWorks Ultrium drives
Note that host adapters check SCSI IDs only at power-on, so any changes will not take effect until the
host system is power-cycled.
•
On internal HP StorageWorks drives, set the SCSI ID by attaching or removing jumpers at the
rear of the drive, see
•
On external HP StorageWorks drives, the ID is displayed on the rear panel and can be set by
pressing the little buttons above and below the number (using a ball point pen), see
the drive's SCSI ID
.
•
On removable HP StorageWorks drives, the ID is set on the back of the tape array, see
the drive's SCSI ID
.
SCSI termination
Terminators are essential, as they provide the correct voltages on the SCSI bus and prevent unwanted
signal reflections from interfering with data transfers. The rule is:
NOTE:
There must be termination at both physical ends of the bus and only at the ends.
There are two main types of termination, active and passive. Active terminators reduce interference
and allow faster data throughput. On devices with high transfer speeds, such as HP StorageWorks
Ultrium devices, active termination is required, using an LVD or multimode active terminator. (Multimode
terminators allow both LVD and single-ended devices to be connected to the same bus. They detect the
type of bus and automatically supply the correct termination.)
Normally the HBA forms one end of the SCSI bus and provides termination. You only need to ensure that
the other end of the bus is terminated.
Removable drives
For HP StorageWorks Ultrium removable tape drives, termination is provided by connecting a terminator
to the spare SCSI connector on the rear of the tape array. There are two connectors for each bay in the
tape array. It does not matter which is used for SCSI-IN and SCSI-OUT.
If you have each removable drive in the tape array attached to a separate bus, then, for each bay in use,
you must attach a terminator to the spare connector for each device.
If you are using the removable drives to mirror backups, you can daisy-chain devices (but no more
than two on each SCSI bus). Connect an LVD-rated cable from the spare SCSI connector for the first
device to one of the SCSI connectors for the second device and attach the terminator to the spare
SCSI connector for the second device.
Refer to your tape array documentation for detailed instructions.
Internal drives
HP StorageWorks Ultrium internal tape drives do not supply termination. A suitably terminated LVD
internal ribbon cable is supplied with the tape drive. The terminator is usually a small, rectangular block
of plastic attached to the cable end and marked ‘SCSI Terminator’.
Ultrium full-height SCSI Tape Drives
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