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

As when returning an OFFLINE plex to ACTIVE, this command starts to recover
the contents of the plex and, after the recovery is complete, sets the plex utility
state to ACTIVE.
■ If the volume is not in use (not ENABLED), use the following command to
re-enable the plex for use:
# vxmend [-g diskgroup] on plex
For example, to re-enable a plex named vol01-02 in the disk group, mydg, enter:
# vxmend -g mydg on vol01-02
In this case, the state of vol01-02 is set to STALE. When the volume is next
started, the data on the plex is revived from another plex, and incorporated
into the volume with its state set to ACTIVE.
If the vxinfo command shows that the volume is unstartable, set one of the
plexes to CLEAN using the following command:
# vxmend [-g diskgroup] fix clean plex
Start the volume using the following command:
# vxvol [-g diskgroup] start volume
See the Veritas Volume Manager Troubleshooting Guide.
Automatic plex reattachment
When a mirror plex encounters irrecoverable errors, Veritas Volume Manager
(VxVM) detaches the plex from the mirrored volume. By default, VxVM
automatically reattaches the affected mirror plexes when the underlying failed
disk or LUN becomes visible. When VxVM detects that the device is online, the
VxVM volume components on the involved LUN are automatically recovered, and
the mirrors become usable.
VxVM uses the DMP failed LUN probing to detect when the device has come online.
The timing for a reattach depends on the dmp_restore_interval, which is a
tunable parameter. The number of LUNs that have reconnected may also affect
the time required before the plex is reattached.
VxVM does not automatically reattach plexes on site-consistent volumes.
When VxVM is installed or the system reboots, VxVM starts the vxattachd
daemon. The vxattachd daemon handles automatic reattachment for both plexes
and sites. The vxattachd daemon also initiates the resynchronization process for
a plex. After a plex is successfully reattached, vxattachd notifies root.
289Creating and administering subdisks and plexes
Reattaching plexes