TMF Planning and Configuration Guide (H06.06+, J06.03+)

Configuring TMF for Backup and Recovery
HP NonStop TMF Planning and Configuration Guide—540136-005
5-6
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 trade-off 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.
Specifying the Prefix for Dump Subvolume Names on Disk
If you direct dumps to disk on the local system, the TMF dump processes automatically
generate dump subvolume names consisting of a two-character alphabetic prefix (the
default is ZT) followed by a six-digit serial number. Dumping to disk on a remote
system requires that you explicitly designate a different prefix. When designating the
disk volume to receive dumps, you can specify the prefix of your choice by appending
it to the disk volume name, as follows:
$BACKUP.AA
One reason you might want to supply your own prefixes is to segregate different
applications’ dumps from one another.