TMF Reference Manual (G06.26+)

TMFCOM Tape Media Considerations
HP NonStop TMF Reference Manual—522418-003
4-2
Other Types of Tape Drives and Devices
Other Types of Tape Drives and Devices
For labeling tapes using tape drives and devices other than open-reel tape drives, you
must omit the DENSITY option from the ADD TAPEMEDIA or SET TAPEMEDIA
command. For example, for labeling tapes on cartridge tape drives, digital audio tape
(DAT) devices, or digital liner tape (DLT) devices, you would not specify the DENSITY
option. If you do include this option for such drives or devices, the command fails and
you receive an error message.
Labeled-Tape Processing Interfaces
TMF tape processing, including the processing of online and audit dumps, requires
labeled tapes. If Guardian labeled-tape processing is not enabled for your system, you
cannot use labeled tapes and thus cannot perform TMF tape-oriented operations.
In general, as a TMF user, you request tape-labeling functions through TMFCOM
commands. For example, the ADD TAPEMEDIA command records tape volume
names in the TMF catalog and writes them to tape volume labels; the DUMP FILES
command locates the required tape volumes in the catalog and transmits dumps to
them. You can, however, communicate directly with a running TMF process to identify
tape volumes by using the MEDIACOM operator interface for labeled-tape processing.
When a TMF operation requires a tape and no appropriate TMF scratch tape is
presently mounted, TMF sends a message to the operator console requesting that a
tape be mounted. The operator can respond by mounting the requested tape or any
other tape defined in the TMF catalog as a scratch tape. If you want to specify an
alternate to the requested tape, you can use the ALTER TAPEMOUNT command in
MEDIACOM. This command issues a new tape-mount request that supersedes the
original TMF request. You might want to employ ALTER TAPEMOUNT, for example, to
use a copy of an input tape when the tape originally requested is unavailable. Or,
when a requested output tape is unavailable, you might want to use the next TMF
scratch tape that can satisfy this request. More specifically, you can use the ALTER
TAPEMOUNT command to perform these tasks:
•
If a requested scratch tape is damaged or unavailable, you can direct TMF to
select instead the next scratch tape listed in the TMF catalog.
•
If the tape-mount request is for an online or audit dump restore operation, you can
direct TMF to select an alternate copy of that dump. You might want to do this, for
example, if multiple copies of the dump were made but one copy has been moved
off-site or damaged.
•
If duplicate copies of tapes were made, you can use ALTER TAPEMOUNT to
select the appropriate tape, with the following constraints for open-reel tapes:
•
If the copies were made in parallel in a multi-reel set of tapes, they are
interchangeable on a reel-for-reel basis−for example, the first reel in Set A is
interchangeable with the first reel in Set B, the second reel in Set A is
interchangeable with the second reel in Set B, and so forth, throughout the set.