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TMF Introduction (G06.24+)

ManualsBrandsHP ManualsServerHP NonStop G-Series
51525354555657585960
Transaction Protection and Database Recovery
HP NonStop Transaction Management Facility (TMF) Introduction—522414-001
3-5
Audit Volumes
Audit Volumes
Audit volumes are the disk volumes that contain audit trail files. There are three types
of audit volumes: active audit volumes, overflow audit volumes, and restore audit
volumes.
Active Audit Volume
The disk volumes that contain active audit trail files are called active audit volumes.
HP requires that you place audit trail files and audited database files on separate disk
volumes so that the database files and audit trail files cannot be damaged by the same
failure.
Overflow Audit Volume
The system manager can configure overflow audit volumes to be used when the active
audit trail is nearing full capacity and no files are available for a rollover. The oldest
audit trail files are copied to the overflow volumes: this allows audit trail files to be
reused.
Typically, overflow volumes are used if TMF is temporarily generating audit records at
a higher rate than anticipated when the audit trail was configured, or if secondary
storage media is not available for audit dumps.
Restore Audit Volume
Restore audit volumes contain audit trail files restored from an audit dump as part of a
TMF recovery procedure. If you configure automatic audit dumping, you must
configure restore audit volumes. Restore audit volumes are used during file recovery.
During recovery of database files, TMF applies changes from audit trail files to the
database. If TMF requires an audit trail file that is no longer available on the system,
the audit dump is restored to the restore audit volume; from the restore audit volume,
TMF reads the audit trail file and applies changes to the database. When the recovery
operation is completed, TMF purges any files it had restored to the restore audit
volume. More information about this recovery operation appears under File Recovery
on page 3-13.
Since restore audit volumes are used only during recovery procedures, you can also
use restore audit volumes as overflow volumes.