TMF Planning and Configuration Guide (G06.26+)

Reconfiguring Audit Trails

HP NonStop TMF Planning and Configuration Guide—522416-005

3-3

Changing the Audit-Trail Configuration

Audit-trail configuration changes affect the size and capacity of audit trails on your

system. Before you change the configuration, refer to reports about typical audit-trail

capacity usage, transactions generated during normal and peak periods, and disk

space on your system; you should keep such reports in a notebook for easy reference.

This section discusses the audit-trail attributes that you can change, and how these

changes can affect your system.

Before you change any of these attributes, consider the relationships between the

attributes.

Number of Files Per Active Audit Volume

Increasing the number of files that reside on each active-audit volume is the

recommended way to increase audit-trail capacity, if there is space on the active-audit

volume (otherwise, add another active-audit volume). You can change the number of

files per active-audit volume while transaction processing is in progress. (TMF can be

either started or stopped; the TMP must be running.)

Increasing the files per active-audit volume causes TMF to create preallocated files on

each active-audit volume for the specified audit trail. If there is not enough disk space

for these files, the number of files per active-audit volume does not change.

Decreasing the number of files that reside on each active-audit volume decreases the

audit-trail capacity. For at least a week, keep a record of the level of audit-trail

capacity used before decreasing the number of files per active-audit volume. Make

sure that decreasing the audit-trail capacity will not cause frequent overflow conditions.

Decreasing the files per active-audit volume causes TMF to delete as many available

audit-trail files and preallocated files (if any) as necessary to arrive at the new number

of files per volume. If all preallocated files are deleted and the volume still contains

more audit-trail files than the new number allows, TMF deletes the extra audit-trail files

when they are no longer needed by the recovery processes.

Note. TMF limits the number of files per active-audit volume to 100 or fewer.

Caution. Before decreasing the size of an audit trail, determine whether such a change might

interrupt transaction processing. TMF does not alert you to the possibility that the audit trail

could exceed its begin-transaction-disable threshold when you decrease the files per active-

audit volume or delete an active-audit volume from the configuration.

If the audit trail exceeds its begin-transaction-disable threshold, new transactions cannot start.

In this case, transaction processing is suspended until audit-trail usage drops below the

threshold.

If the overflow threshold is exceeded as a result of reduced audit-trail capacity, the first pinned

audit-trail file (one that contains or is receiving active-audit information) is copied to the

overflow-audit volume.