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. Thevxattachd daemon also initiates the resynchronization process for a plex. After a plex is successfully reattached, vxattachd notifies root.

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:

These CVM considerations also apply to automatic site reattachment.

See Automatic site reattachment.