VERITAS Volume Manager 3.5 Troubleshooting Guide (September 2004)

Recovery from Hardware Failure
Understanding the Plex State Cycle
Chapter 1
11
Understanding the Plex State Cycle
Changing plex states are part of normal operations, and do not necessarily indicate
abnormalities that must be corrected. A firm understanding of the various plex states
and their interrelationship is necessary if you want to be able to perform the recovery
procedure described in this chapter.
The Figure 1-1, “Main Plex State Cycle,” 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.
The next 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.