TMF Operations and Recovery Guide (G06.24+)

Recovery Methods
HP NonStop TMF Operations and Recovery Guide—522417-002
7-4
Recovering Multiple Volumes
Volume recovery repairs the audited files on a volume by:
1. Redoing the changes written to cache but not to disk at the time the volume went
down: this redo action ensures that the files reflect all the work recorded in the
audit trail. During this step, the volume recovery process generates EMS Message
401:
Phase 1 of recovery completed at
atseqno atseqno RBA rba.
2. Undoing incomplete changes for all files that the volume-recovery process, during
Step 1, either
°
Marked “undo needed,” or
°
For which encountered an associated file-incomplete record during the redo
pass, but did not find a subsequent file-complete record.
During this step, the volume recovery process generates EMS Message 403:
Phase 3 of recovery completed at
atseqno atseqno RBA rba.
When volume recovery succeeds in recovering a file, the file’s open status returns to
the normal state. If volume recovery cannot successfully recover a file, it marks that
file to indicate that further repair must be done by the file recovery process (as
discussed under File Recovery on page 7-7). After all audited files on a volume have
either been successfully recovered or marked for file-recovery repair, volume recovery
starts the volume for TMF processing.
Recovering Multiple Volumes
If you want volume recovery to run on several volumes that were previously disabled,
specify them in one ENABLE DATAVOLS command. This method is more efficient
than issuing multiple commands. If the volumes specified are accessible (up) before
the command is issued, then all of the volumes will probably be recovered in a single
volume recovery process. If a volume specified in the ENABLE DATAVOLS command
is down, it will probably have to wait to be recovered until another volume recovery
process can run. On a given system, multiple volume recovery processes can run
concurrently. The maximum number of these processes equals the number of
configured processors, for a maximum of 8. For example, a 6-processor system can
have up to 6 volume-recovery processes running; a 10-processor system can have up
to 8.
Recovering a Disabled Volume
A volume can be started for TMF processing after it has been disabled with the
DISABLE DATAVOLS command, as long as the necessary audit dumps are available.
Similar to file recovery, volume recovery can use the dumped audit-trail files to recover
the disabled volume.