HOWTO Recreate boot logical volume (BLV)

Introduction

If a Boot Logical Volume (BLV) is corrupted, a machine will not boot. By example bad block in a disk might cause a corrupted BLV. This page threats how to resote that BLV.

Recreate boot logical volume

To fix this issue, boot the server in maintenance mode, from a CD ROM, a tape or a NIM if available.

The bootlists are set using the bootlist command or through the System Management Services progam (SMS). pressing F1 will go to SMS Mode. If you have an HMC, then at the time of booting select boot as SMS in the properties of that partition.

Note that the bosboot command requires that boot logical volume hd5 exists. To create a BLV (that may had been deleted by mistake), create a new hd5 logical volume of one PP size that must be in rootvg, specify boot as logical volume type using the following command:

Command: creating the BLV
# mklv -y hd5 -t boot rootvg 1

Then change the bootlist for service (maintenance) mode as 1st device to the CD ROM using the following command:

Command: changing the bootlist
# bootlist -m service cd0 hdisk0 hdisk1

Then start maintenance mode for system recovery, access the volume group rootvg to start a shell and recreate the BLV using the bosboot command as following:

Command: recreating the BLV
# bosboot -ad /dev/hdisk0

it's important to perform a proper shutdown, all changes need to be written from the memory to the disks.

Command: rebooting the system
# shutdown -Fr