TMF Operations and Recovery Guide (G06.26+)

The TMF Catalog
HP NonStop TMF Operations and Recovery Guide—522417-003
6-12
Using Tapes of Different Sizes
rack. Using this scheme, tape ABC12 occupies the twelfth slot in the third rack (C) of
cabinet AB. You can specify reel identifiers using uppercase and lowercase letters;
TMF001 is the same as tmf001.
If you have more than one system in the same area, you might want to use one
character of the reel identifier to indicate which system the tape belongs to. Another
technique to separate two or more systems housed in the same room might be to
identify one as the “red” system and the other as the “gray” system, using red and gray
labels accordingly.
Using Tapes of Different Sizes
Using tape volumes of the same length for all dumps is recommended. It is ideal if an
audit dump fills a single tape volume.
If you use tape volumes of different lengths to make multiple parallel copies of a dump,
the dump process treats all the tape volumes as if they were the same length as the
shortest one.
For example, two copies are made of a dump that is stored on two tape volumes.
Part 1 of copy 1 is written to a 600-foot tape volume, and part 1 of copy 2 is written to a
1200-foot tape volume. When the dump process reaches the end of the 600-foot tape
volume for copy 1, it also terminates part 1 of copy 2 and prompts the operator to
mount more tape volumes for part 2 of both copy 1 and copy 2.
Using tape volumes of different lengths wastes some space on the tape volume;
however, all parallel copies are interchangeable. You could use copy 2 of parts 1
and 2 and copy 1 of part 3 to recover the file, or you could recover the file by using all
three parts of copy 1.
Displaying Tape Media Entries
Use the INFO TAPEMEDIA command to display the name and status of tape volumes
in the TMF catalog. You can request a display of all tape volumes in a specific state,
specific tape volumes, or specific tape volumes in a specific state. Any user allowed to
use TMFCOM can use the INFO TAPEMEDIA command, whether or not TMF is
running.
The following INFO TAPEMEDIA command sends a list of released tape volumes to
output device DUMP1:
27> TMFCOM/ OUT $S.#DUMP1/
TMF 1> INFO TAPEMEDIA, STATUS RELEASED
Note. If tape errors occur during dumps, the TMF catalog (through the TMFDR process)
marks the associated tape volume released, even if the catalog is configured to mark reusable
tape volumes scratch. An unexpectedly high number of released tape volumes may indicate
that you have damaged tapes: check the EMS log for archive tape OPEN or WRITE errors.