Veritas FlashSnap Point-In-Time Copy Solutions 5.0 AdministratorÆs Guide, HP-UX 11i v3, First Edition, May 2008

46 Off-host cluster file system backup
Using off-host processing to back up cluster file systems
Repeat steps 2 through 14 each time that you need to back up the volume.
In some instances, such as recovering the contents of a corrupted volume, it may
be useful to resynchronize a volume from its snapshot volume (which is used as
a hot standby):
# vxsnap -g diskgroup restore volume source=snapvol destroy=yes|no
The destroy attribute specifies whether the plexes of the snapshot volume are
to be reattached to the original volume. For example, to resynchronize the
volume cfs_vol from its snapshot volume scfs_vol:
# vxsnap -g exampledg restore cfs_vol source=scfs_vol destroy=no
Note: You must unmount the file system that is configured on the original
volume before attempting to resynchronize its contents from a snapshot.
Reattaching snapshot plexes
Note: This operation is not supported for space-optimized instant snapshots.
Using the following command, some or all plexes of an instant snapshot may be
reattached to the specified original volume, or to a source volume in the
snapshot hierarchy above the snapshot volume:
# vxsnap [-g diskgroup ] reattach snapvol source= vol \
[nmirror=
number ]
By default, all the plexes are reattached, which results in the removal of the
snapshot. If required, the number of plexes to be reattached may be specified as
the value assigned to the nmirror attribute.
Note: The snapshot being reattached must not be open to any application. For
example, any file system configured on the snapshot volume must first be
unmounted.
For example the following command reattaches 1 plex from the snapshot
volume, snapmyvol, to the volume, myvol:
# vxsnap -g mydg reattach snapmyvol source=myvol nmirror=1
While the reattached plexes are being resynchronized from the data in the
parent volume, they remain in the SNAPTMP state. After resynchronization is
complete, the plexes are placed in the SNAPDONE state.