TMF Planning and Configuration Guide (H06.05+)

Configuring TMF for Backup and Recovery
HP NonStop TMF Planning and Configuration Guide—540136-002
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Dumping to Disk Instead of Tape
Disk dumps can almost always be performed automatically, as long as there is enough
disk space available. However, if audit dumps are written to a disk that is also used for
key system applications, you might want to manage audit dumps to minimize inter-disk
activity during peak hours. You can use the DISABLE AUDITDUMP command to
pause audit dumping until the system is less active, and then use the ENABLE
AUDITDUMP command to resume audit dumping. These commands can be issued
only by members of the super user group.
Because audit dumping can be directed to either tape or disk, you might want to use
both media, on an alternating basis, to protect your database. Periodic dumps to tape
might be necessary if disk space is not available or if you need to save the audit-trail
files on tape.
You can change the dump media while TMF is started.
Dumping to Disk Instead of Tape
You can configure your system to direct both audit dumping and online dumping to disk
instead of magnetic tape. The most compelling reason for doing so would be at an
installation that will be unattended much of the time, so that no one is onsite to do the
necessary tape handling. (In planning such an installation, you might also consider the
alternative of using cartridge tapes and an automated tape library).
Another reason for dumping to disk is that, on the rare occasions when you must do
file recovery, restoration of the necessary audit dumps and online dumps is done faster
than from tape media, and without operator intervention. If you choose to dump to
disk, the principal tradeoff is a greater initial investment in disk drives.
To direct audit dumps to disk, include the MEDIUM DISK and ADDDISKMEDIA options
in an ALTER AUDITDUMP command.
To direct online dumps to disk, include the DISKMEDIA option in the DUMP FILES
command.
Caution. Audit dumps must occur routinely for audit trails configured with the audit dump
feature set to ON. Otherwise, the audit trail will reach overflow capacity and can eventually
reach the begin-transaction-disable threshold; if this threshold is reached, TMF does not allow
new transactions to start.
If you automate the audit dump procedure, it is best to configure overflow volumes and then
monitor the system closely for a few days to make sure the procedure is fully functional.
If audit dumps are not occurring regularly, do the following to determine the source of the
problem:
•
Check the event log.
•
Monitor disk space usage.