AIX 5L Problem Determination - IBM Redbooks

2. Select Change Show use of an SSA Physical disk. The disk must be
returned to general use as an AIX system disk.
3. If the disk is to be removed from the system, use the relevant AIX commands.
Do not remove the pdisk until you have removed the disk from the system
using the SSA service aids.
If you are presented with this situation, and the disk with the problem was not a
member of a RAID set on this machine, your only option to return this disk to
normal use is to do a low-level format using the SSA service aid. This can take
time if the disk is 9 GB or larger.
SSA RAID
The SSA subsystem is capable of being operated by some adapters as either
single system disks or as RAID LUNs. Provided that all has been set up
correctly, then the RAID implementation works well. If you have any doubts as to
how the RAID is set up, refer to SSA Adapters: User’s Guide and Maintenance
Information, SA33-3272.
If you need to do anything involving an SSA RAID array, then use the relevant
procedure listed. This will ensure that the integrity of the RAID set is maintained
at all times.
Changing SSA disks
SSA disks are hot swappable. When preparing AIX for the removal of an SSA
disk, do not use the rmdev command to remove the pdisk prior to physically
removing the disk from the enclosure. You will need the pdisk to do the following
steps. Use the rmdev command for the pdisk only when all steps are completed.
1. Use the SSA Service Aid to power the disk off prior to removal. This is done
by using the set service mode and identify facility. This will put the disks on
either side of the one you want to remove into string mode and power off the
disk to be removed.
2. When the replacement disk or blanking module is inserted, use the same
Service Aid to reset service mode. This will initialize the new disk and take the
other disks out of string mode.
3. At this point, you can now run the rmdev command to remove the pdisk
allocated to the disk you removed.
4. The disk change procedures will then tell you to run the cfgmgr command to
create a new pdisk for the replaced physical disk.
56 IBM ^ Certification Study Guide - AIX 5L Problem Determination Tools and Techniques