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

Implementing Off-Host Processing Solutions

274 VERITAS Volume Manager Administrator’s Guide

The following sections describe how you can apply off-host processing to implement

regular online backup of a volume in a private disk group, and to set up a replica of a

production database for decision support. Two applications are outlined in the following

sections:

◆ Implementing Online Backup

◆ Implementing Decision Support

These applications use the Persistent FastResync and disk group move, split and join

features of VxVM in conjunction with volume snapshots.

Implementing Online Backup

This section describes a procedure for implementing off-host online backup for a volume

in a private disk group. The intention is to present an outline of how to set up a regular

backup cycle 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, or how to perform the backup itself.

To back up a volume in a private disk group, use the following procedure.

1. Use the following command on the primary host to see if the volume is associated

with a datachange object (DCO)andDCO volumethatallow PersistentFastResyncto

be used with the volume:

# vxprint -g volumedg -F%hasdcolog volume

This command returns on if there is a DCO and DCO volume; otherwise, it returns

off.

If the volume is not associated with a DCO object and DCO volume, follow the

procedure described in “Adding a DCO and DCO Volume” on page 193.

2. Use the following command on the primary host to check whether FastResync is

enabled on a volume:

# vxprint -g volumedg -F%fastresync volume

This command returns on if FastResync is enabled; otherwise, it returns off.

If Persistent FastResync is disabled, enable it using the following command on the

primary host:

# vxvol -g volumedg set fastresync=on volume