VERITAS Volume Manager 3.5 Administrator's Guide (September 2002)

Chapter 11, Configuring Off-Host Processing
Implementing Off-Host Processing Solutions
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4. Prepare the OHP host to receive the snapshot volume that contains the copy of the
database tables. This may involve setting up private volumes to contain any redo
logs, and configuring any files that are used to initialize the database.
5. On the primary host, suspend updates to the volume that contains the database
tables. The database may have a hot backup mode that allows you to do this by
temporarily suspending writes to its tables.
6. On the primary host, make a snapshot volume, snapvol, using the following
command:
# vxassist -g volumedg snapshot [nmirrors=N] volume snapvol
If required, use the nmirrors attribute to specify the number of mirrors in the
snapshot volume.
If a database spans more than one volume, specify all the volumes and their snapshot
volumes on the same line, for example:
# vxassist -g dbasedg snapshot vol1 snapvol1 vol2 snapvol2 \
vol3 snapvol3
7. On the primary host, release the tables from hot backup mode.
8. On the primary host, use the following command to split the snapshot volume into a
separate disk group, snapvoldg, from the original disk group, volumedg:
# vxdg split volumedg snapvoldg snapvol
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 split. 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