TMF Operations and Recovery Guide (G06.24+)

Recovery Methods
HP NonStop TMF Operations and Recovery Guide—522417-002
7-5
Volume Recovery Failures
Volume Recovery Failures
When the volume recovery process fails to recover a volume, you can usually correct
the problems that caused the failure. Consider the following guidelines:
•
A volume must be up before it can be repaired by the volume recovery process.
Use the SCF STATUS DISK command to view the state of the volume. Use the
SCF START DISK command to change the state, if necessary. If the volume was
previously disabled, use the ENABLE DATAVOLS command to restart the volume
recovery process. (The SCF STATUS DISK and SCF START DISK commands are
described in the SCF Reference Manual for G-Series RVUs.)
•
The active-audit volumes must be available for the volume recovery process to
read the audit-trail files.
•
On systems with a very large number of data volumes or a large number of files
accessed by a single transaction, volume recovery may not be able to perform its
recovery operation with its current memory allocation. If this happens, use the
ALTER PROCESS command to increase the EXTENDEDSEGSIZE attribute of the
volume recovery process and then stop the process. TMF automatically restarts
the process with the larger extended segment allocation. Refer to the TMF
Reference Manual for instructions on using the ALTER PROCESS command. For
specific recommendations, refer to the TMF Planning and Configuration Guide.
•
If the volume recovery process stops or the processor running the volume recovery
process fails, the volume recovery process restarts automatically once the problem
is corrected.
•
A volume cannot be started for TMF processing until all transactions pending on
the system have been committed or aborted; volume recovery runs automatically
after the transactions complete. This means you may have to manually abort or
resolve a transaction that was not able to complete while a volume was disabled,
or to abort long-running transactions on the system. If you have an application
with a long-running transaction, a possible alternative is to bring that application
down; this action may allow the transaction to finish and volume recovery to
complete. See Controlling Individual Transactions on page 3-20 for more
information.
•
If an error prevents the volume recovery process from redoing or undoing a
change to a data file, volume recovery marks the file to indicate that recovery is still
required. The FUP INFO command identifies recovery-needed files with the letter
R: you must explicitly use the file recovery process to recover these files.
Access to a file marked recovery-needed is prohibited until the file has been
recovered. Recover the files by issuing the RECOVER FILES command, as
described in File Recovery on page 7-7.