Veritas Storage Foundation 5.1 SP1: Storage and Availability Management for Oracle (5900-1504, April 2011)

Resynchronizing the snapshot to your database
When you have finished using a clone database or want to refresh it, you can
resynchronize it with the original database. This is also known as refreshing the
snapshot volume or merging the split snapshot image back to the current database
image. After resynchronizing, the snapshot can be retaken for backup or
decision-support purposes.
When resynchronizing the data in a volume:
■ Resynchronize the snapshot from the original volume. This procedure is
explained in this section.
■ Resynchronizing the original volume from the snapshot. This choice is known
as reverse resynchronization. Reverse resynchronization may be necessary
to restore a corrupted database and is usually much quicker than using
alternative approaches such as full restoration from backup media.
Note: The reverse resynchronization option is not available for Oracle RAC
environments.
You can resynchronize the snapshot from the original volume.
■ You must be logged in as the Oracle database administrator.
■ Before you can resynchronize the snapshot image, you must
validate a snapplan and create a snapshot.
See “About creating database snapshots” on page 146.
See “Validating a snapplan (dbed_vmchecksnap)” on page 167.
See “Creating a snapshot (dbed_vmsnap)” on page 174.
■ If a clone database has been created, shut it down and unmount
the file systems using the dbed_vmclonedb -o umount
command. This command also deports the disk group if the primary
and secondary hosts are different.
See “Shutting down the clone database and unmounting file
systems” on page 187.
■ The Oracle database must have at least one mandatory archive
destination.
Prerequisites
■ The dbed_vmsnap command can be executed on either host.
■ In an off-host configuration, the dbed_vmsnap command imports
the disk group that was deported from the secondary host and
joins the disk group back to the original disk group. The snapshot
volumes again become plexes of the original volumes. The snapshot
is then resynchronized.
■ See the dbed_vmsnap(1M) manual page for more information.
Usage Notes
191Using Database FlashSnap for backup and off-host processing
FlashSnap commands