Veritas Volume Manager 5.0 Troubleshooting Guide Guide (September 2006)

11Recovery from hardware failure
Understanding the plex state cycle
Understanding the plex state cycle
Changing plex states are part of normal operations, and do not necessarily indicate
abnormalities that must be corrected. A clear understanding of the various plex states and
their interrelationship is necessary if you want to be able to perform the recovery
procedures described in this chapter.
Figure 1-1 shows the main transitions that take place between plex states in VxVM. (For
more information about plex states, see the chapter “Creating and Administering Plexes”
in the Veritas Volume Manager Administrator’s Guide.)
Figure 1-1 Main plex state cycle
At system startup, volumes are started automatically and the vxvol start task makes
all CLEAN plexes ACTIVE. At shutdown, the
vxvol stop task marks all ACTIVE
plexes CLEAN. If all plexes are initially CLEAN at startup, this indicates that a controlled
shutdown occurred and optimizes the time taken to start up the volumes.
Figure 1-2 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.
PS: CLEAN
PKS: DISABLED
PS: ACTIVE
PKS: ENABLED
Start up
(vxvol start)
Shut down
(vxvol stop)
PS = plex state
PKS = plex kernel state