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Why are some disks not available during recovery of AIX system?

Why are some disks not available during recovery of AIX system?
When booting up from Storix boot media, some of the disks on the system are not available. How do I get the disks on my RAID adapter available to restore to?


ANSWER

The most likely reason the disks are not available is because the support for the disks were not included in the boot media. There is a good reason for that and there is also a solution.

The reason the support was not included is because these disks are not bootable disks. This was done by IBM design in support of mksysb. A mksysb installation only allows you to reinstall rootvg, hence, IBM decided not to include the disk/adapter support in the proto or proto extension files to prevent users from installing rootvg on disks that are not bootable. Storix, on the other hand, will allow you to reinstall rootvg and any other data from other volume groups.

To make these non-bootable disks available as target disks to restore non-rootvg data, you will need to create a proto extension file that has the files needed to configure the adapter and disks. I will provide an example:

Adapter: PCI 4-Channel Ultra3 SCSI RAID Adapter
Disk: SCSI Disk Array RAID5

1. Find the define, configure, and change methods that support the adapter and disk.
# odmget PdDv | grep -p scraid

The output indicates that I will need the following files to support the adapter:
Define = "/usr/lib/methods/define_rspc"
Configure = "/usr/lib/methods/cfgscraid"
Change = "/usr/lib/methods/chgscraid"

The output indicates that I will need the following files to support the disk:
Define = "/usr/lib/methods/define"
Configure = "/usr/lib/methods/cfgscrdisk"
Change = "/usr/lib/methods/chgdisk"

2. Check to see if these methods are already included in proto or proto extension files (/usr/lib/boot/* and /usr/lib/boot/protoext/*). You do not want to have duplicate entries.

3. If you do not find your methods in any of the proto or proto extension files then create one with your methods.
Create a file /usr/lib/boot/protoext/tape.proto.ext.scsi.raid.rte
The contents of the file should look like this (I have included all of the methods I will need to configure my adapter and disk, excluding the methods that existed in other proto or proto extension files):
cfgscrdisk ---- 777 0 0 /usr/lib/methods/cfgscrdiskscraid_ddpin ---- 777 0 0 /usr/lib/drivers/pci/scraid_ddpinscraid_dd ---- 777 0 0 /usr/lib/drivers/pci/scraid_ddchgscraid ---- 777 0 0 /usr/lib/methods/chgscraidcfgscraid ---- 777 0 0 /usr/lib/methods/cfgscraid

4. Re-create your boot media

NOTE: These non-bootable disks will now be available for you to select as target disks for installation, including rootvg. Do not use these disks for rootvg because they are not bootable.

Also, the new proto extension file you created now allows you to reinstall rootvg onto these disks when using mksysb. Again, these disks are not bootable and should not be used for rootvg.