Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

367Configuring off-host processing
Implementing off-host processing solutions
Note: This step sets up the snapshot volumes, and starts tracking changes to the
original volumes. When you are ready to create a replica database, proceed to step 6.
6 On the primary host, suspend updates to the volume that contains the database tables.
A database may have a hot backup mode that allows you to do this by temporarily
suspending writes to its tables.
7 Create the snapshot volume, snapvol, by running the following command on the
primary host:
# vxsnap -g volumedg make \
source=volume/snapvol=snapvol/snapdg=snapvoldg
If a database spans more than one volume, you can specify all the volumes and their
snapshot volumes using one command, as shown in this example:
# vxsnap -g dbasedg make \
source=vol1/snapvol=snapvol1/snapdg=sdg \
source=vol2/snapvol=snapvol2/snapdg=sdg \
source=vol3/snapvol=snapvol3/snapdg=sdg
This step sets up the snapshot volumes ready for the backup cycle, and starts tracking
changes to the original volumes.
8 On the primary host, if you temporarily suspended updates to a volume in step 6,
release all the database tables from hot backup mode.
9 On the primary host, deport the snapshot volume’s disk group using the following
command:
# vxdg deport snapvoldg
10 On the OHP host where the replica database is to be set up, use the following
command to import the snapshot volume’s disk group:
# vxdg import snapvoldg
11 The snapshot volume is initially disabled following the join. Use the following
commands on the OHP host to recover and restart the snapshot volume:
# vxrecover -g snapvoldg -m snapvol
# vxvol -g snapvoldg start snapvol
12 On the OHP host, check and mount the snapshot volume. The following are sample
commands for checking and mounting a file system:
# fsck -F vxfs /dev/vx/rdsk/snapvoldg/snapvol
# mount -F vxfs /dev/vx/dsk/snapvoldg/snapvol mount_point
13 On the OHP host, use the appropriate database commands to recover and start the
replica database for its decision support role.
When you want to resynchronize the snapshot volume’ s data with the primary database,
you can refresh the snapshot plexes from the original volume as described below:
1 On the OHP host, shut down the replica database, and use the following command to
unmount the snapshot volume: