TMF Planning and Configuration Guide (G06.24+)

Doing an Initial Configuration
HP NonStop TMF Planning and Configuration Guide—522416-004
2-3
Adding the Master Audit Trail (MAT)
The audit-trail file size is one of the few parameters that you cannot change while TMF
is started. To change the configured file size after starting TMF, you must stop your
applications, stop TMF, delete the TMF configuration, and reconfigure the audit trail.
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 files per
active volume or explicitly controlling when audit dumps occur. These changes are
discussed further in Number of Files Per Active Audit Volume on page 3-3 and
Managing Audit Dumps on page 5-4.
Number of Audit-Trail Files per Active-Audit Volume
You use the FILESPERVOLUME parameter of the ADD AUDITTRAIL command to
specify the number of audit-trail files on the active-audit volume.
The maximum number of audit-trail files per active-audit volume is either the size of the
active-audit volume divided by the file size value (rounded down) or 100, whichever
number is smaller. (TMF limits the number of files per active-audit volume to 100 or
fewer.)
The minimum number of files per active-audit volume is 3.
If the active-audit volume has its own dedicated disk drive, use the maximum files per
active volume value; in all other cases, use the minimum files per active volume value.
Table 2-2 summarizes these guidelines.
Table 2-1. Audit-Trail File Size
File Size Value
Maximum 95% of the capacity of one tape.
Minimum 5 megabytes.
Recommended If the daily audit generation rate is expected to be greater than the
maximum file size, use the maximum file size; otherwise, use the daily
audit generation rate as the file size.
Table 2-2. Number of Audit Files Per Active-Audit Volume
Files per Active
Volume Value
Maximum (Active-audit volume size ÷ file size (rounded down)) or 100,
whichever number is smaller
Minimum 3
Recommended If the active volume has its own dedicated disk drive, use the
maximum files per active volume; otherwise use the minimum
files per active volume.