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

53Decision support
Creating an off-host replica database
To set up a replica database to be used for decision support on an OHP host
1 If you have not already done so, prepare the OHP host to use the snapshot
volume that contains the copy of the database tables. Set up any new
database logs and configuration files that are required to initialize the
database. See “Preparing a replica Oracle database” on page 73 for details of
this procedure for an Oracle database.
2 On the primary host, use the following command to make a full-sized
snapshot, snapvol, of the tablespace volume by breaking off plexes from the
original volume:
# vxsnap -g volumedg make \
source=volume/newvol=snapvol/nmirror=N
The nmirror attribute specifies the number of mirrors, N, in the snapshot
volume.
If the volume does not have any available plexes, or its layout does not
support plex break-off, use the procedure described in “Creating a volume
for use as a full-sized instant snapshot” on page 27 to prepare an empty
volume for the snapshot, and then use the following command to create the
snapshot:
# vxsnap -g volumedg make source=volume/snapvol=snapvol
If a database spans more than one volume, specify all the volumes and their
snapshot volumes as separate tuples on the same line, for example:
# vxsnap -g dbasedg make source=vol1/snapvol=svol1 \
source=vol2/snapvol=svol2 source=vol3/snapvol=svol3
Note: This step sets up the snapshot volumes, and starts tracking changes
to the original volumes. When you are ready to create the replica database,
proceed to step 3.
3 Suspend updates to the volumes. Oracle supports online backup by
temporarily suspending updates to the datafiles of the tablespaces, provided
that the database is running in archive mode and the tablespaces are online.
As the Oracle database administrator, put each tablespace into hot backup
mode using a script such as that shown in “Script to put an Oracle database
into hot backup mode” on page 65.
4 On the primary host, refresh the contents of the snapshot volumes from the
original volume using the following command:
# vxsnap -g volumedg refresh snapvol source= vol \
[
snapvol2 source= vol2 ]... syncing=yes
The syncing=yes attribute starts a synchronization of the snapshot in the
background.
For example, to refresh the snapshots svol1, svol2 and svol3:
# vxsnap -g dbasedg refresh svol1 source=vol1 \
svol2 source=vol2 svol3 source=vol3