Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

330 Administering volume snapshots
Creating instant snapshots
The following example demonstrates how to restore the volume, myvol, from the space-
optimized snapshot, snap3myvol.
# vxsnap -g mydg restore myvol source=snap3myvol
Dissociating an instant snapshot
The following command breaks the association between a full-sized instant snapshot
volume, snapvol, and its parent volume, so that the snapshot may be used as an
independent volume:
# vxsnap [-f] [-g diskgroup] dis snapvolume|snapvolume_set
This operation fails if the snapshot, snapvol, has a snapshot hierarchy below it that
contains unsynchronized snapshots. If this happens, the dependent snapshots must be fully
synchronized from snapvol. When no dependent snapshots remain, snapvol may be
dissociated. The snapshot hierarchy is then adopted by snapvol’s parent volume.
Note: To be usable after dissociation, the snapshot volume and any snapshots in the
hierarchy must have been fully synchronized. See “Controlling instant snapshot
synchronization” on page 333 for more information. In addition, you cannot dissociate a
snapshot if synchronization of any of the dependent snapshots in the hierarchy is
incomplete. If an incomplete snapshot is dissociated, it is unusable and should be deleted
as described in “Removing an instant snapshot” on page 330.
The following command dissociates the snapshot, snap2myvol, from its parent volume:
# vxsnap -g mydg dis snap2myvol
Note: When applied to a volume set or to a component volume of a volume set, this
operation can result in inconsistencies in the snapshot hierarchy in the case of a system
crash or hardware failure. If the operation is applied to a volume set, the
-f (force) option
must be specified.
Removing an instant snapshot
When you have dissociated a full-sized instant snapshot, you can use the vxedit
command to delete it altogether, as shown in this example:
# vxedit -g mydg -r rm snap2myvol
You can also use this command to remove a space-optimized instant snapshot from its
cache. For details of how to remove a cache, see “Removing a cache” on page 336.