VERITAS Volume Manager 4.1 Administrator's Guide

Creating and Administering Plexes
Displaying Plex Information
Chapter 6 213
Plex States
Plex states reflect whether or not plexes are complete and are consistent
copies (mirrors) of the volume contents. VxVM utilities automatically
maintain the plex state. However, if a volume should not be written to
because there are changes to that volume and if a plex is associated with
that volume, you can modify the state of the plex. For example, if a disk
with a particular plex located on it begins to fail, you can temporarily
disable that plex.
NOTE A plex does not have to be associated with a volume. A plex can be
created with the vxmake plex command and be attached to a volume
later.
VxVM utilities use plex states to:
• indicate whether volume contents have been initialized to a known
state
• determine if a plex contains a valid copy (mirror) of the volume
contents
• track whether a plex was in active use at the time of a system failure
• monitor operations on plexes
This section explains the individual plex states in detail. For more
information about the possible transitions between plex states and how
these are applied during volume recovery, see the chapter
“Understanding the Plex State Cycle” in the section “Recovery from
Hardware Failure” in the VERITAS Volume Manager Troubleshooting
Guide.
Plexes that are associated with a volume have one of the following states:
ACTIVE Plex State
A plex can be in the ACTIVE state in two ways:
• when the volume is started and the plex fully participates in normal
volume I/O (the plex contents change as the contents of the volume
change)