Sunday, December 11, 2011

Fix a corrupted BLV in AIX

If a Boot Logical volume (BLV) is corrupted, a machine will not boot.
(Eg:bad block in a disk might cause a corrupted BLV)

To fix this situation, You must boot your machine in maintenance mode, from a CD or Tape. If a NIM has been setup for a machine, you can also boot the machine from a NIM master in maintenance mode.

The bootlists are set using the bootlist command or through the SystemManagement Services Progam (SMS). pressing F1 will go to SMS Mode.

then change the bootlist for service(maintenance) mode as 1st device to CD ROM.

#bootlist -m service cd0 hdisk0 hdisk1

then start maintenance mode for system recovery,

Access rootvg,

access this volum group to start a shell,

then recreate BLV using bosboot command.

#bosboot -ad /dev/hdisk0

it's important that you do a proper shutdown, All changes need to be written from memory to disk.

#shutdown -Fr

Imp: bosboot command requires that boot logical volume hd5 exists. If you wan create a BLV ( may be it had been deleted by mistake ), do the following,

1. boot your machine in maintenance mode,
2. Create a new hd5 logical volume, one PP size, must be in rootvg,specifyboot as logical volume type,

#mklv -y hd5 -t boot rootvg 1

3. Then run bosboot command as described.

If you have an HMC, then at the time of booting select boot as SMS in theproperties of that partition.