TMF Supplement for Large Audit Files (G06.24+)

TMF Planning and Configuration Guide
HP NonStop TMF Supplement for Large Audit-Trail Files—527391-001
3-3
Increasing Audit-Trail Capacity (Pages 3-6 through
3-7)
To change the audit-trail file size after TMF is started, issue an ALTER AUDITTRAIL
command containing the desired FILESIZE parameter.
If you err in choosing the most appropriate audit-trail file size, it would be better from
an operational standpoint to specify a file size that is too large rather than too small. In
either case, you can compensate for the miscalculation later by changing the file size,
changing the files per active volume, or explicitly controlling when audit dumps occur.
These changes are discussed further in the TMF Planning and Configuration Guide,
under “Number of Files Per Active Audit Volume” on page 3-3 and “Managing Audit
Dumps” on page 5-4.
Increasing Audit-Trail Capacity
(Pages 3-6 through 3-7)
As your business grows, your applications process more and more transactions. This
causes a corresponding increase in the amount of space used on the active-audit
volume, and an increase in the use of overflow-audit volumes.
If TMF must copy files from an active-audit volume on one disk drive to an overflow-
audit volume on another disk drive too often, TMF performance could be noticeably
affected. If transactions generate a large enough amount of audit information that the
available overflow space is consistently exceeded, your application risks reaching the
begin-transaction-disable threshold, which further degrades performance.
System administrators should regularly monitor audit-trail capacity. If you detect that
the audit trail is consistently exceeding the overflow threshold, you should issue an
ALTER AUDITTRAIL command, while transaction processing is in progress, to do any
of the following:
•
Increase the number of audit-trail files on the active-audit volume.
•
Add another active-audit volume.
•
Change the audit-trail file size. Doing so is more disruptive than either of the
above alternatives, however, and should be used only when long-term planning
suggests the need to increase the file size.
Table 3-1. Audit-Trail File Size
File Size Value
Recommended Minimum 300 megabytes.
Recommended Maximum The daily audit-generation rate.
Note. Before changing the number of files per active-audit volume or adding active-audit
volumes, make sure that the overflow threshold is not set too low, as described in Changing the
Overflow Threshold on page 3-8.