Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Chapter 9, Administering Volume Snapshots
Creating Instant Snapshots
289
For a space-optimized instant snapshot, the cached data is used to recreate the contents of
the specified volume. The space-optimized instant snapshot remains unchanged by the
restore operation.
Note For this operation to succeed, the volume that is being restored and the snapshot
volume must not be open to any application. For example, any file systems that are
configured on either volume must first be unmounted.
It is not possible to restore a volume from an unrelated volume.
The destroy and nmirror attributes are not supported for space-optimized
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 (vxsnap dis)
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 292 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 290.
The following command dissociates the snapshot, snap2myvol, from its parent volume:
# vxsnap -g mydg dis snap2myvol