TMF Planning and Configuration Guide (G06.24+)

Configuring TMF for Backup and Recovery

HP NonStop TMF Planning and Configuration Guide—522416-004

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Loss of an Active Audit Volume

If you lose an active-audit volume, TMF comes to an abrupt halt. To reconstruct the

volume, you must use audit dumps; any undumped material, however, is lost and

cannot be recovered.

There are three things you can do to protect yourself against the loss of an active-audit

volume:

1. Use mirrored volumes.

2. Perform audit dumps regularly.

3. Use NEXT AUDITTRAIL commands, if necessary, to keep the amount of

undumped audit material on the current active-audit volume at an acceptable level.

As in most production TMF environments, you should use mirrored volumes for the

active-audit volumes. This practice significantly reduces your chances of losing any

undumped material.

Depending on how often your system produces audit dumps, you might want to use

NEXT AUDITTRAIL commands to force audit dumps more often. If your system

generates an audit-trail rollover only once every other day, for example, you run the

risk of losing up to two days’ worth of audit material. In that type of situation, you might

want to issue a NEXT AUDITTRAIL command twice a day, reducing your worst

possible loss to a fourth of what it was previously.

For similar reasons, you should be prompt about performing audit dumps when they

are requested. If you defer an audit dump and then lose the active-audit volume

containing the undumped audit-trail file, you will lose that file.

Loss of the Entire System

In anticipating the possible loss of your entire system (including all files not backed up

to secondary media such as tape), you need to consider the following questions:

1. How quickly must you recover?

2. How many transactions can you afford to lose?

3. How much capital are you willing to invest?

In general, the more quickly you need to recover, the more advance planning you need

to do and the more frequently you need to perform dumps and backups. The fastest

means of recovery with the least loss of data can be obtained by using the Remote

Duplicate Database Facility (RDF). With the RDF product, you can be up and running

within minutes after losing your primary system.