VERITAS Storage Foundation 4.1 Intelligent Storage Provisioning Administrator's Guide

Chapter 5, Administering Instant Snapshots

Implementing Off-Host Processing Solutions

11. On the OHP host, use the following command to deport the snapshot volume’s disk group:

# vxdg deport snapvoldg

12. On the primary host, re-import the snapshot volume’s disk group using the following

command:

# vxdg import snapvoldg

13. On the primary host, use the following command to rejoin the snapshot volume’s disk group

with the original volume’s disk group:

# vxdg join snapvoldg volumedg

14. The snapshot volume is initially disabled following the join. Use the following commands on

the primary host to recover and restart the snapshot volume:

# vxrecover -g volumedg -m snapvol

# vxvol -g volumedg start snapvol

The contents of the snapshot volume are now ready to be refreshed.

Repeat steps 2 through 14 each time that you need to back up the volume.

Implementing Decision Support

This section describes a procedure for implementing off-host decision support for a volume in a

private disk group. The intention is to present an outline of how to set up a replica database by

combining the Persistent FastResync and disk group split and join features of VxVM. It is beyond

the scope of this guide to describe how to configure a database to use this procedure.

To set up a replica database using the table files that are configured within a volume in a private

disk group, use the following procedure.

1. 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.

2. Create a full-sized instant snapshot volume, snapvol, using the following command on the

primary host:

# vxsnap -g volumedg make source=volume/snapvol=snapvol

This command uses the specified prepared snapshot volume, snapvol, to form the snapshot

volume. (See “Creating a Volume for Use as a Full-Sized Instant Snapshot” on page 76 for

details.)