IBM ServeRAID-4 Ultra160 Series User Reference page 174

Troubleshooting ServeRAID subsystems in a cluster environment
Following is a series of common problems and solutions that can help you
troubleshoot your IBM ServeRAID Cluster Solution.
Problem
The ServeRAID Manager program shows
physical drives in defunct state.
ServeRAID shared logical drives do not
failover properly.
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IBM User's Reference: ServeRAID
Action
1. Enable the View shared drives feature in the ServeRAID
Manager program. Doing so displays a drive as reserved, instead
of defunct, in the following situations:
v A drive has been moved.
v A drive has failed-over to the other server in the cluster.
Note: It is normal for drives in the above situations to display as
defunct if you have not enabled the View shared drives feature.
In this case, the drives shown in the defunct state are not really
defective.
2. Check RAID level-1 and RAID level-5 arrays to make sure they
are not in critical state. If they are in critical state, replace the
failed drive and perform a rebuild operation.
1. Ensure that the resource type of each ServeRAID controller
shared disk resource is IBM ServeRAID logical disk.
If the resource type is shown as physical drive, the localquorum
option was not specified properly when MSCS under Windows
NT 4.0 was installed.
To correct this problem, you must reinstall the high-availability
cluster solution using Microsoft Windows NT.
2. Ensure that shared SCSI buses on the ServeRAID controller pair
are connected in the same way that corresponding SCSI
channels are connected. For example, SCSI channel 1 on the
controller in the first cluster server is connected to SCSI channel
1 on the controller in the second cluster server, channel 2 is
connected to channel 2, and so forth.
3. Ensure that the physical SCSI drives that contain logical drives
are all connected to shared SCSI channels.
4. Ensure that there are no more than eight shared logical drives
defined per pair of ServeRAID controllers.
5. Make sure each shared logical drive has a unique merge group
number assigned. Shared merge group numbers must be in the
range 1–8.
6. Make sure each ServeRAID controller has been assigned a
unique controller name and that each ServeRAID controller has
its partner name assigned properly to correspond to the
ServeRAID controller in the other cluster server that is attached
to the shared SCSI buses.
7. Check for loose shared SCSI bus cables.
8. Ensure that the physical drives that are expected to be moved or
to failover show up in a ready or reserved state on the server that
is attempting to take control of these drives.
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-4 Ultra160 SCSI Controller