Chapter 5 - Troubleshooting
Common SCSI Bus Problems
58
Common SCSI Bus Problems
SCSI bus problems can usually be attributed to cabling issues. Refer to the chart
below to review troubleshooting and fault isolation procedures to assist you in
identifying the suspect component or problem, and the possible solutions.
SCSI Bus Symptom
Probable Cause
Solution
Host SCSI BIOS scan
hangs.
Possible termination or
SCSI ID conflict.
Check the Host ID and proper
system configuration. Check the
SCSI ID on the RAID Controller
ports.
Not all drives
connected to the
HBA channels are
displayed during
boot.
Possible SCSI ID conflict.
Check that the SCSI connectors
are properly connected. Check
SCSI ID assignments.
If the enclosure is the
daisy-chained enclosure, check
the SCSI ID assignments for each
controller.
SCSI Bus hangs, SCSI
Bus excessively
retries, and/or drives
drop offline.
Faulty connectivity.
Re-check the cable connections.
If you have daisy-chained
storage systems connected on
the SCSI bus, you will need to
perform some fault isolation.
If all the drives on one bus are
offline, start with the daisy-chain
storage system. Disconnect the
data cable. If the remaining
drives return to a normal state it
indicates that the isolated storage
system has the faulty component.
If this does not return the
remaining drives to a normal
state, it is a good indication that
the problem is in the first storage
system and/or its controller.
You may use a controller from
the other storage system or a
“new” known good controller.
Substitute this controller for the
suspect controller and it should
return the storage system bus to
a normal condition.
NOTE
: A return to a normal
condition is indicated by the
drives coming back online.
After the faulty controller is
replaced, begin re-connecting
the data cables, noting the SCSI
bus and drives remain in a
normal state.
Re-check the cables.
4700S.book Page 58 Wednesday, April 6, 2005 2:14 PM
