VERITAS Storage Foundation 4.1 Oracle Administrator's Guide

Resynchronizing the Snapshot to Your Database Prerelease 8 September 2005, 8:55am
250 VERITAS Storage Foundation for Oracle Administrator’s Guide
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.
There are two choices when resynchronizing the data in a volume:
◆ Resynchronizing the snapshot from the original volume. This option 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.
Prerequisites
◆ You must be logged in as the Oracle database administrator.
◆ Before you can resynchronize the snapshot image, you must complete the steps in “Summary
of Database Snapshot Steps” on page 216, “Validating a Snapplan (dbed_vmchecksnap)” on
page 229, and “Creating a Snapshot (dbed_vmsnap)” on page 235.
◆ 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 248.
Usage Notes
◆ The dbed_vmsnap command can only be executed on the primary host.
◆ In a two-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.
◆ You cannot access the Database FlashSnap commands (dbed_vmchecksnap,
dbed_vmsnap, and dbed_vmclonedb) with the VxDBA menu utility.
▼ To resynchronize the snapshot image
Use the dbed_vmsnap command as follows: