Thursday, December 30, 2010

An introduction to VERITAS Volume Manager plex states and what they mean

Problem

An introduction to VERITAS Volume Manager plex states and what they mean

Solution

Empty Plex State
This is seen on a newly created volume that has not been initialized.

Clean Plex State
The plex contains a good copy of the volume data.

Note: A volume is not startable if one plex is in the CLEAN state and some plexes are in the ACTIVE state. Thus, several vxmend fix operations are normally used in conjunction to set all plexes in a volume to STALE and then to set one plex to CLEAN. A volume start operation will then enable the CLEAN plex and recover the STALE plexes by copying data from the one CLEAN plex.

Active plex State
Volume is started and the plex fully participates in the normal volume I/O operation.

Stale Plex State
The plex does not have the complete current contents. If I/O errors occur on a plex, the kernel stops using and updating this plex and the operation sets the state of the plex in STALE state.

OFFLINE Plex State
This happens when the plex is detached from the volume. Any changes to the volume are not reflected to the plex while in the OFFLINE state.

TEMP Plex State
You get this state when you add a new mirror to a volume. The plex will be in this state while it is being associated or attached (sync process). A utility will set the plex state to TEMP at the start of an operation and to an appropriate state at the end of the operation.

TEMPRM Plex State
This resembles TEMP state except that at the completion of the operation, the TEMPRM plex is removed. If the system goes down for any reason, a TEMPRM plex state indicates the operation is incomplete and a subsequent vxvol start will disassociate plexes and remove the TEMPRM plex.

TEMPRMSD Plex State
This is used by vxassist when attaching new plex. If the operation does not complete, the plex and subdisk are removed.

IOFAIL Plex State  
This is associated with persistent logging. On the detection of a failure of an ACTIVE plex, vxconfigd places that plex in the IOFAIL state so that it is disqualified from the recovery selection process a volume start time.

Please refer or consult the Volume Manager Administrator Guide for further information concerning Plex states.

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