VERITAS Volume Manager 4.1 Troubleshooting Guide

Recovery from Hardware Failure
Understanding the Plex State Cycle
Chapter 114
The figure Figure 1-2, “Additional Plex State Transitions,” shows additional transitions that
are possible between plex states as a result of hardware problems, abnormal system
shutdown, and intervention by the system administrator.
When first created, a plex has state EMPTY until the volume to which it is attached is
initialized. Its state is then set to CLEAN. Its plex kernel state remains set to DISABLED and
is not set to ENABLED until the volume is started.
Figure 1-2 Additional Plex State Transitions
After a system crash and reboot, all plexes of a volume are ACTIVE but marked with plex
kernel state DISABLED until their data is recovered by the vxvol resync task.
A plex may be taken offline with the vxmend off command, made available again using
vxmend on, and its data resynchronized with the other plexes when it is reattached using
vxplex att. A failed resynchronization or uncorrectable I/O failure places the plex in the
IOFAIL state.
Recover data
(vxvol resync)
Initialize plex
(vxvol init clean)
Take plex offline
(vxmend off)
Shut down
(vxvol stop)
After crash
and reboot
(vxvol start)
Uncorrectable
I/O failure
Put plex online
(vxmend on)
Resync data
(vxplex att)
Resync
fails
Create plex
PS: EMPTY
PKS: DISABLED
PS: ACTIVE
PKS: DISABLED
Start up
(vxvol start)
PS: CLEAN
PKS: DISABLED
PS: ACTIVE
PKS: ENABLED
PS: OFFLINE
PKS: DISABLED
PS: IOFAIL
PKS: DETACHED
PS: STALE
PKS: DETACHED
PS = Plex State
PKS = Plex Kernel State