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

Restoring the Original Volume from a Snapshot
274 VERITAS Volume Manager Administrator’s Guide
Restoring the Original Volume from a Snapshot
For traditional snapshots, the snapshot plex is resynchronized from the data in the
original volume during a vxassist snapback operation. Alternatively, you can choose
the snapshot plex as the preferred copy of the data when performing a snapback as
illustrated in “Resynchronizing an Original Volume from a Snapshot.” Specifying the
option -o resyncfromreplica to vxassist resynchronizes the original volume from
the data in the snapshot.
Resynchronizing an Original Volume from a Snapshot
Note The original volume must not be in use during a snapback operation that specifies
the option -o resyncfromreplica to resynchronize the volume from a snapshot.
Stop any application, such as a database, and unmount any file systems that are
configured to use the volume.
For instant snapshots, the vxsnap restore command may be used to restore the
contents of the original volume from an instant snapshot or from a volume derived from
an instant snapshot. The volume that is used to restore the original volume can either be a
true backup of the contents of the original volume at some point in time, or it may have
been modified in some way (for example, by applying a database log replay or by running
a file system checking utility such as fsck) to create a synthetic replica. All synchronization
of the contents of this backup or synthetic replica volume must have been completed
before the original volume can be restored from it. The original volume is immediately
available for use while its contents are being restored.
Note You can perform either a destructive or non-destructive restoration of an original
volume from an instant snapshot. Only non-destructive restoration is possible from
a space-optimized snapshot. In this case, the snapshot remains in existence after the
restoration is complete.
Original
volume
snapshot
Snapshot
volume
Snapshot
mirror
-o resyncfromreplica snapback
Refresh on
snapback