Veritas Storage Foundation 5.0 for Oracle RAC Configuration Guide Extracts for HP Serviceguard Storage Management Suite, Second Edition, May 2008

Using FlashSnap for Backup and Recovery
Creating a Snapshot (dbed_vmsnap)
Chapter 5
100
Creating a Snapshot (dbed_vmsnap)
The dbed_vmsnap command creates a snapshot of an Oracle database by splitting the
mirror volumes used by the database into a snapshot database. You can use the snapshot
image on either the same host as the database or on a secondary host provided storage is
shared by the two hosts.
The snapshot image created by dbed_vmsnap is a frozen image of an Oracle database’s
datafiles. The dbed_vmsnap command ensures that a backup control file is created when
the snapshot database is created, which allows for complete data recovery, if needed.
For Database FlashSnap status information, see the Veritas Storage Foundation for
Oracle Administrator’s Guide.
NOTE You cannot access Database FlashSnap commands (dbed_vmchecksnap, dbed_vmsnap,
and dbed_vmclonedb) with the VxDBA menu utility.
To create a snapshot
1. Change directories to the working directory in which your snapplan is stored:
$ cd /working_directory
2. If SNAPSHOT_MODE is set to offline in the snapplan, shut down the database.
3. Create the snapshot image using the dbed_vmsnap command:
Table 5-7 Create Snapshot Notes
Prerequisites • You must be logged in as the Oracle database administrator.
• You must create and validate a snapplan using
dbed_vmchecksnap before you can create a snapshot image with
dbed_vmsnap.
Usage Notes • The dbed_vmsnap command can only be used on the primary
host.
• Do not share volumes between Oracle database files and other
software.
• When creating a snapshot volume, create the snapshot on a
separate controller and on separate disks from the primary
volume.
• Make sure your archive log destination is separate from your
Oracle database volumes.
• Do not place any datafiles, including control files, in the
$ORACLE_HOME/dbs directory.
• Resynchronization speed varies based on the amount of data
changed in both the primary and secondary volumes when the
mirror is broken off.
•See the dbed_vmsnap(1M) manual page for more information.