General Volume Group Recovery

This appendix contains examples of possible recovery techniques for various potential failures. The examples are presented as is, with no guarantee, and should be used only if the problem is fully understood.

Unlike the examples in Practical Examples that were executed in an AIX Version 4 environment, the examples here are presented in an AIX V3.2 environment. Hence, although the recovery principles are similar for AIX Version 4 and AIX V3.2, some modifications of the following procedures may be required.

Disk Power Supply Failure

Scenario: System has two volume groups, rootvg and vg00. Volume group vg00 has an external disk drive, hdisk4. The power supply fails on hdisk4, the disk media itself is not harmed.

General Disk Failure

Scenario: System has two volume groups, rootvg and vg00. A disk in vg00 fails and must be replaced. The disk name is hdisk5. The LVs on hdisk5 are: /dev/lvpat, /home/pat, /dev/lvcad, and /cad (mirror copy).

Recovery After a Disk Is Replaced -- 1

Scenario: System has two volume groups, rootvg and vg00. Volume group vg00 contains three drives, hdisk1, hdisk2 and hdisk3. hdisk3 failed and has been replaced prior to any clean up. The LVs on hdisk3 are:

/dev/lvpat    /home/pat
/dev/lvca     /cad (mirror copy)

Recovery After a Disk Replaced -- 2

Scenario: System has two volume groups, rootvg and vg00. Volume group vg00 has three disk drives in it, hdisk1, hdisk2 and hdisk3. hdisk3 failed and has been replaced prior to any clean up. Don't know what LVs were on hdisk3.

Disk Failure Recovery -- rootvg

Scenario: System has two disks in rootvg, hdisk0 and hdisk1. Most of the operating system is on hdisk0. hdisk0 fails and there is data on hdisk1 that needs be recovered. The logical volumes on hdisk1 are:

/dev/lv0      /home/cad1
/dev/lv01     /home/wordper
/dev/loglv00  log logical volume

Disk Failure -- rootvg

Scenario: System has four disks in the rootvg. LVs hd1, hd2, hd3, hd4 hd6 and hd6 are on hdisk0. The LV hd9var is on hdisk1. Other user LVs are 1, on hdisk1, hdisk2 and hdisk3. hdisk1 and hdisk2 fail, system now boots ot to 552 (cannot varyon the rootvg due to lack of quorum).

Recovering after Losing VGDA

Scenario: System had a volume group vg00. Volume group vg00 included hdisk2 and hdisk3. hdisk2 failed and VGDA is broken on hdisk3.