TMF Operations and Recovery Guide (G06.26+)

Occasional Operations
HP NonStop TMF Operations and Recovery Guide—522417-003
3-12
Specifying Recovery Mode
By default, all configured data volumes are automatically started:
•
When you start TMF
•
When the volume comes up after a volume failure (if TMF is started at the time)
Data volumes automatically stop processing audit information when you stop TMF.
Specifying Recovery Mode
When you add a data volume, you can specify its recovery mode.
Setting the recovery mode to ONLINE means that the audit-trail files that would be
needed to recover the data volume remain on the active or overflow-audit volumes:
this way, the volume recovery process does not have to restore audit-trail files from
archive media. Using online mode keeps audit-trail files pinned on the active-audit trail
longer, which means there must be sufficient space to hold the files until they are no
longer needed for volume recovery.
Setting the recovery mode to ARCHIVE means that the audit-trail files that would be
needed to recover this data volume are copied to tape or disk. Archive mode is
allowed only if the audit trail for this data volume is configured for audit dumping. Using
archive mode frees audit-trail space sooner, which can prevent overflow or begin-
transaction-disable conditions.
You should usually configure data volumes with online recovery mode, which is the
default. Archive mode should be used only in exceptional circumstances, such as
when a volume will be down for a long time and will later require recovery, and you do
not want to disrupt other OLTP applications. In these circumstances, consider
temporarily deleting a data volume from the TMF configuration if it was shut down
cleanly or does not contain critical data.
Permanently Removing Data Volumes
Deleting a data volume removes it from the TMF configuration, which potentially
decreases the number of audit records generated. Before you can delete a data
volume, you must disable it. TMF recovery is not done on a deleted data volume; if
volume recovery is needed, it must be done before the data volume is deleted (see
Volume Recovery on page 7-3). You must re-add a data volume to the TMF
configuration before that volume can be restarted for transaction processing.
Caution. If you use archive recovery mode, you must perform regular online dumps to ensure
that the audit dumps stay current in the TMF catalog. If you do not perform online dumps for a
data volume configured with archive recovery mode, and the volume contains no data files that
have been dumped (with the TMFCOM DUMP FILES command), TMF may reuse the required
audit dumps.
Note. TMF is shipped from the factory with the $DSMSCM disk volume configured as a TMF
data volume. Although you are free to add other TMF data volumes to the configuration, you
should not remove $DSMSCM as a TMF data volume.