TMF Reference Manual (G06.24+)

TMFCOM Commands
HP NonStop TMF Reference Manual—522418-002
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ALTER AUDITTRAIL
AUDITDUMP Option Considerations
If you set the AUDITDUMP attribute to ON after TMF has been running with
AUDITDUMP OFF, the first file dumped is the file to which audit information is being
written (the current file). For example, if audit information is being written to file
sequence number 12 when AUDITDUMP ON is specified, the first file to be dumped
will be sequence number 12.
Changing AUDITDUMP from ON to OFF may impact file recovery: after an undumped
audit-trail file is renamed or purged, file recovery cannot be performed through that file.
For example, if file sequence number 23 is not yet dumped when AUDITDUMP is set
to OFF, then, after file 23 is renamed or purged, file recovery cannot recover files
beyond audit-trail file number 22 (however, file recovery to a timestamp before the end
of file number 22 is still possible).
To set AUDITDUMP to OFF for the master audit trail, you must also set it to OFF for all
auxiliary audit trails in the configuration. To set AUDITDUMP to OFF for any audit trail,
you must also set RECOVERYMODE to ONLINE for all data volumes that use this
audit trail.
When you issue an ALTER AUDITTRAIL command that sets AUDITDUMP to OFF,
TMF displays a confirmation message that allows you to either verify that you want to
take this action or to indicate that you do not.
MAXRETAINEDATFILES Option Considerations
During volume recovery or file recovery, if TMF requires an audit-trail file that is no
longer available on the system but is archived on tape, TMF restores that file from an
audit dump on the tape to a restore-audit volume on disk. When the recovery process
completes, TMF purges this file and all other unneeded files from the restore-audit
volume. When TMF is processing multiple recovery operations, whether serially or in
parallel, a recovery process often must wait for TMF to restore the audit- trail file
repeatedly to support each recovery operation.
To make TMF keep audit-trail files restored from tape on the restore-audit volume
indefinitely, enter the ALTER AUDITTRAIL command with the MAXRETAINEDATFILES
option. This action overrides the standard restore-and-purge mechanism and
enhances performance by:
•
Eliminating or minimizing the time a recovery process must wait for TMF to restore
an audit-trail file.
•
Minimizing disk contention for audit-trail files being read from, or restored to, the
same disk.
Note. For audit-trail files dumped to disk, TMF opens the disk-dump copy directly, rather than
copying it to a restore-audit volume. Therefore, for audit-trail files on disk, the entire disk-
restore time is eliminated and all recovery processing (even the first) need not wait for this
restore operation. Therefore, you do not specify MAXRETAINEDATFILES for audit-trail files on
disk.