HP StorageWorks DAT Tape Drives User Guide - SCSI (April 2005)

Before you start10
• 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)
.
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.
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. The 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 Ultra160 or Ultra320 SCSI bus. 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.
NOTE: The drives are not compatible with high voltage differential (HVD) SCSI devices.
.
How can I check the SCSI bus type and SCSI ID?
For many operating systems, you can install and run HP Library & Tape Tools from either the
HP StorageWorks Tape CD-ROM or www.hp.com/support/tapetools
to check your server’s current
SCSI configuration (see also ”Diagnostic tools” on page 49). This will provide information about the
SCSI bus and the SCSI IDs in use.
Table 1 Supported SCSI bus types
SCSI Bus Type Supported
Ultra160 LVD, Ultra320 LVD Yes. These are recommended configurations.
Ultra2 LVD, Ultra Wide LVD Yes. These are supported, but performance may be impaired.
Ultra wide, single-ended Yes. But this is not a recommended configuration as it will restrict
performance.
Ultra narrow, single-ended Yes. But this is not recommended as it will severely restrict
performance and you will need a suitable cable or adapter.
High Voltage Differential No. The drive will not work and you may damage the drive or
controller