Recover a corrupted root filesystem in VxVM

1. Boot the system to VxVM maintenance mode. Interrupt the autoboot process at EFI:

Shell> fs1: fs1:\> hpux -vm

VxVM maintenance mode
* HP-UX Boot Loader for IA-64  * Version 1.65 *** Type 'help' for help ****
Press Any Key to interrupt Autoboot \efi\hpux\AUTO ==> boot vmunix

\efi\hpux\AUTO ==> boot vmunix
Seconds left till autoboot - 10

Interrupt the autoboot process in the HP-UX boot loader:

HPUX> boot vmunix -vm

> System Memory = 4091 MB loading section 0 loading section 1 .....
INFO: VxVM Maintenance Mode Boot - vxconfigd aborted
INIT: Overriding default level with level 's'
INIT: SINGLE USER MODE
INIT: Running /sbin/sh

Warning: The VxVM configuration daemon, vxconfigd, does not normally
run in MMB mode, and only one copy of the root volume data is used. If the
system has a mirrored root volume, writing to the root file system can thus
cause file system corruption when both mirrors are subsequently
configured. To prevent this, start VxVM in MMB mode by running the
vx_emerg_start command. This marks the non-boot mirror plexes as stale,
and so forces a recovery from the boot mirror to the non-boot mirrors to
take place. After VxVM has been started in MMB mode, various recovery
options can be performed depending on the nature of the problem

2. Recover the root filesystem:

# vx_emerg_start

The root volume can usually be repaired by using the following command:

# vxvol -g rootdg -f start rootvol

If the root volume is mirrored, recovery is started. Wait until recovery completes and the command exits. Then run the fsck command and mount the root file system as shown here:

# fsck -F vxfs -o full /dev/vx/rdsk/rootdg/rootvol
# mkdir /tmp_mnt
# mount -F vxfs /dev/vx/dsk/rootdg/rootvol /tmp_mnt

The following form of the vx_emerg_start command combines all these operations in a single command to recover the root volume and its mirrors, check the root file system, and mount it:

# vx_emerg_start -m hostname

OPTIONS
      -m   Mounts the root file system contained on the rootvol volume after
           VxVM has been started.  Prior to being mounted, the rootvol
           volume is started and fsck is run on the root file system.

2. When you have recovered the volumes on the VxVM root disk, and performed any other necessary repairs, reboot the system:

# reboot