Create or fix boot logical volume(BLV) of AIX

This article details step by step procedure how to Create, Recreate or fix boot logical volume (BLV) on AIX  with example .
If a boot logical volume is corrupted (for example, bad blocks on a disk might cause a corrupted BLV), a machine will not boot from a shutdown.
To fix this situation, you must boot your machine in maintenance mode, from a CD or tape. If NIM has been set up for a machine, you can also boot the machine from a NIM master in maintenance mode.
After booting from CD, tape or NIM an Installation and Maintenance Menu is shown and you can startup the maintenance mode. We will cover this later in this unit. After accessing the rootvg, you can repair the boot logical volume with the bosboot command. You need to specify the corresponding disk device, for example hdisk0:
# bosboot -ad /dev/hdisk0

It is important that you do a proper shutdown.  All changes need to be written from memory to disk.
But the above bosboot command requires that the boot logical volume hd5 exists. If you ever need to re-create the BLV from scratch – the following steps should be followed:

1. Boot your machine in maintenance mode (from CD or tape or Nim).
2. Create a new hd5 logical volume: one physical partition in size, must be in rootvg. Specify boot as logical volume type.
3. Run the bosboot command as described.
4. Reboot the server.

Now Let see the above 4 steps in little more details with  an example as below 
1. Boot your machine in maintenance mode (from CD, tape, or NIM).
2. Create a new hd5 logical volume: one physical partition in size, must be in rootvg. Specify boot as logical volume type. if needed, remove hd5 using # rmlv -f  hd5
# mklv -y hd5 -t boot -a e rootvg 1
3. Run the bosboot command as described below.
# bosboot -ad /dev/hdisk0
4. Reboot the system
shutdown -Fr

When we go a major change it is always recommended to re-created BLV on the PVs present on rootvg using the command
bosboot -ad /dev/hdiskXX
where XX = LUN number like hdisk00, hdisk01 etc

* Article Source from : Internet