Setting the scsi id on hp storageworks dat drives, Scsi termination – HP StoreEver DAT Tape Drives User Manual

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If none of these is available to you, try the following sources of information:

•

The details of all installed devices and settings may have been written down and stored with

your computer's documentation (for new computers, this is often done by the supplier).

•

Your HBA's documentation should tell you which settings it uses.

•

Look at each device to find out its ID. This is usually easy with external devices. With internal

devices, you will probably need the help of the device's documentation to identify the SCSI ID

setting, which is usually set with jumpers.

Setting the SCSI id on HP StorageWorks DAT drives

For all cases, see the User Guide that came with your tape drive for more details. 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 ”

•

On removable HP StorageWorks drives, the ID is set on the back of the tape array, see ”

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:

•

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

DAT 72 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. The terminator

supplied with HP StorageWorks DAT72 tape drives in LVD only. Multimode terminators may be used

instead.)
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.