TMF Operations and Recovery Guide (G06.24+)

Occasional Operations
HP NonStop TMF Operations and Recovery Guide—522417-002
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Altering the Size of an Audit Trail
whether their transactions were committed or aborted. Aborted transactions are
undone by the backout process when TMF is started again.
There are two situations in which you might choose to include the ABRUPT option:
1. You have issued a STOP TMF command, but something in the environment is
preventing a clean shutdown from occurring.
2. You have altered some of the process attributes (such as the CPU or the process
priority) of the TMP and you want to stop, and then restart, the TMP to activate the
new attribute values. Refer to the TMF Planning and Configuration Guide for
information about altering TMF process configurations.
To restart TMF, issue a START TMF command.
See the TMF Reference Manual for additional instructions on using the STOP TMF
command.
Altering the Size of an Audit Trail
TMF writes before-images, after-images, and TMF control records to an audit trail.
TMF uses the information in the audit trail when it needs to perform a recovery
operation such as transaction backout or volume recovery.
Determining the size and location of an audit trail is one of the tasks involved in
configuring a TMF system; once configured, audit trails need only to be dumped
regularly to run smoothly. You might need to alter the size of the audit trail in response
to two potential problems:
•
The audit trail is nearing the overflow threshold
•
TMF is aborting transactions because too much of the audit trail has filled since the
transactions began
This section discusses how to respond to those problems.
Caution. The STOP, ABRUPT command, of course, can disrupt customer applications. If the
audit trails are not disturbed while TMF is down, any transactions aborted when the STOP,
ABRUPT operation occurs should be properly backed out when TMF is restarted, and the
database should remain consistent. Nevertheless, you should only use the ABRUPT option at
times of low transaction activity.
Caution. Before issuing a STOP TMF, ABRUPT command on a production system, contact
the Global Customer Support Center (GCSC) or your service provider to confirm the validity of
what you are about to do.