TMF Reference Manual (G06.26+)

TMFCOM Commands
HP NonStop TMF Reference Manual—522418-003
3-72
ALTER AUDITTRAIL
If you specify COMMITHOLDMODE or COMMITHOLDTIMER values when TMF is
stopped, the new values take effect when TMF is again started.
Other Operational Considerations
Additional guidelines apply to the ALTER AUDITTRAIL command.
When you specify the ALTER AUDITTRAIL command with DELETEACTIVEVOL for an
active-audit volume or DELETEOVERFLOWVOL for an overflow volume, and that
volume holds audit-trail files needed by TMF for backout, volume recovery, or system
restart, the volume is marked as “deleting.” Any preallocated files stored on the
volume are purged immediately, and new files are not written to the volume. When no
more audit-trail files reside on the volume, it is removed from the TMF configuration.
Once a disk volume is defined in the TMF configuration as an active or overflow
volume, that volume cannot be taken down through an SCF STOP DISK command
until all audit-trail files are purged from it by TMF and the volume is removed from the
audit-trail configuration. All volumes defined as active or overflow volumes must be
accessible before TMF can be started.
When TMF conducts overflow processing, it attempts to enhance performance by
using an approach called “same-volume optimization.” For more information about this
approach, see the discussion OVERFLOWVOL and OVERFLOWTHRESHOLD Option
Considerations on page 3-20.
Note. Always remember:
•
The COMMITHOLDMODE ON, COMMITHOLDMODE OFF, and RESET
COMMITHOLDMODE settings apply to a specified audit trail.
•
The COMMITHOLDMODE SUSPEND and COMMITHOLDTIMER settings apply to
commit-hold status across the TMF system, affecting all audit trails.
Caution. Before you decrease the size of the audit trail, determine whether such a change
might interrupt transaction processing. TMF does not alert you to the possibility that the audit
trail could exceed its BEGINTRANSDISABLE threshold when you issue an ALTER
AUDITTRAIL command to decrease the files per active volume or delete an active volume
from the configuration.
If the audit trail exceeds its BEGINTRANSDISABLE threshold, new transactions cannot start.
In this case, transaction processing is suspended until audit trail capacity drops below the
threshold.
If the OVERFLOW threshold is exceeded as a result of reduced audit trail capacity, the first
pinned audit-trail file is copied to the overflow volume.
Be careful not to lower the BEGINTRANSDISABLE or OVERFLOW threshold below your TMF
system’s current capacity levels; they will engage precisely in accordance with your request.