TMF Planning and Configuration Guide (G06.26+)

Configuring TMF for Backup and Recovery
HP NonStop TMF Planning and Configuration Guide—522416-005
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Automatic Volume Recovery
Automatic Volume Recovery
The TMF volume recovery process repairs audited files on a data volume after a disk
or volume failure. When TMF is started after a failure, volume recovery is automatically
initiated on all data volumes, using the audit-trail files maintained by TMF. Volume
recovery is also initiated on a data volume whenever the volume is brought back up
after being down, or when it is enabled after being disabled.
You can view the status of data volumes by using the STATUS DATAVOLS command.
The status tells you whether a volume is queued for recovery or is currently being
recovered.
In addition, the Event Management Service (EMS) log might contain event messages
that indicate problems encountered during a volume recovery operation or the status of
an operation.
File Recovery
In most situations, volume recovery can recover a database; however, in cases such
as media failure, file recovery might be necessary. If a system or media failure
jeopardizes the consistency of one or more audited files, those files cannot be opened
again until they have been recovered and the database restored to a state of
consistency.
File recovery uses the audit-trail information automatically maintained by TMF, but
requires you to perform regular online dumps of your database and to restore files from
the dumps when needed for recovery.
Strategies for Online Dumps and Audit Dumps
Online dumps are not done automatically: operators must explicitly initiate them by
issuing a DUMP FILES command.
TMF does not require you to make online dumps. If you want to be able to use the file
recovery feature, however, you must have at least one online dump of every file that
you might need to recover, and all audit trails associated with those files must be
configured for audit dumping.
When planning for online dumping, you must decide the following:
•
Which database tables and files to dump
•
How often to dump them
•
How to do the dumping most efficiently
Depending upon the types and sizes of the applications running on your system, you
can use a variety of strategies.