HP StorageWorks Ultrium 960 User's And Service Manual page 52

Problem
SCSI ID
Changed drive SCSI ID, but the
host server does not recognize
the new ID.
Autoloader Performance
The autoloader is not efficiently
backing up data.
52 Diagnostics and troubleshooting
Solution
• Make sure that all SCSI devices on the same bus have unique
ID numbers.
• If the SCSI bus is narrow (50-pin) only SCSI IDs 0 through 7
are available.
• Make sure that you cycle power on the autoloader after
changing the SCSI ID.
• Reboot the host server.
• Check the network bandwidth from the host computer. If you
are backing up data over a network, consider comparing to
a local-only backup.
• Make sure the autoloader and tape drive are on their own
SCSI bus and not daisy-chained to another tape drive or to
the hard drive being backed up.
• Make sure the autoloader is connected to a LVDS SCSI bus
and there are no SE devices on the same bus, because this
will cause the entire bus to negotiate down to SE speed.
• Use an Ultra320 SCSI bus and high-quality cabling with 1/8
Ultrium 960 Tape Autoloaders.
Do not connect the autoloader to a narrow SCSI bus.
•
• Try a new cartridge. A marginal cartridge can cause
performance problems due to bad spots on the tape requiring
retries.
• Backing up data that compresses poorly or is already
compressed will lower performance.
• Check the size of the files. Small file size can impact
performance.
• Confirm that the backup application is utilizing block sizes of
at least 32KB, preferably 64KB. Refer to the backup
application documentation for details.
• Make sure the backup server has enough memory to handle
the bandwidth of the backup or restore.
• Clean the tape drive. See
page 43 for instructions.
"Cleaning the Tape Drive" on