Veritas Volume Manager 5.1 SP1 Administrator"s Guide (5900-1506, April 2011)

To disable automatic plex attachment, remove vxattachd from the start up scripts.
Disabling vxattachd disables the automatic reattachment feature for both plexes
and sites.
In a Cluster Volume Manager (CVM) the following considerations apply:
■ If the global detach policy is set, a storage failure from any node causes all
plexes on that storage to be detached globally. When the storage is connected
back to any node, the vxattachd daemon triggers reattaching the plexes on
the master node only.
■ The automatic reattachment functionality is local to a node. When enabled on
a node, all the disk groups imported on the node are monitored. If the automatic
reattachment functionality is disabled on a master node, the feature is disabled
on all shared disk groups and private disk groups imported on the master node.
■ The vxattachd daemon listens for "dmpnode online" events using vxnotify to
trigger its operation. Therefore, an automatic reattachment is not triggered
if the dmpnode online event is not generated when vxattachd is running. The
following are typical examples:
■ Storage is reconnected before vxattachd is started; for example, during
reboot.
■ In CVM, with active/passive arrays, if all nodes cannot agree on a common
path to an array controller, a plex can get detached due to I/O failure. In
these cases, the dmpnode will not get disabled. Therefore, after the
connections are restored, a dmpnode online event is not generated and
automatic plex reattachment is not triggered.
These CVM considerations also apply to automatic site reattachment.
See “Automatic site reattachment” on page 483.
Moving plexes
Moving a plex copies the data content from the original plex onto a new plex. To
move a plex, use the following command:
# vxplex [-g diskgroup] mv original_plex new_plex
For a move task to be successful, the following criteria must be met:
■ The old plex must be an active part of an active (ENABLED) volume.
■ The new plex must be at least the same size or larger than the old plex.
■ The new plex must not be associated with another volume.
Creating and administering subdisks and plexes
Moving plexes
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