DSM/Tape Catalog User's Guide

Tape File Concepts
DSM/Tape Catalog User’s Guide — 520233-008
2 - 10
Tape File Expiration
Generation 3 has two versions of MASTER_OUT. Because DSM/TC allows only
one valid version in a generation, it marks the most current entry for generation 3
the valid one, which is the file created from the rerun.
Tape File Expiration
File catalog entries with a status of invalid stay in the file catalog until the next run of
the clean-up process. The clean-up process is built into DSM/TC, and it runs without
interfering with tape requests or the cataloging of new files and tape. The automated
tape file expiration process is initiated by $ZSVR in the file MEDDEM.
$ZSVR initiates the clean-up process once every 24 hours to physically delete invalid
tape file and disk file entries in every file catalog of the nodes in the system search list.
The automatic run time is the same time that $ZSVR was started on the node. For
example, assume that system software, including DSM/TC, was installed on a node
starting at 6:00 a.m. At 9:00 a.m. $ZSVR is started. Beginning the next day at 9:00
a.m, the clean-up process runs. It continues to run every day at 9:00 a.m. To change
the time the clean-up process runs, stop and restart $ZSVR at the time you prefer.
Automated tape file expiration is launched at the earliest time specified in SSLIST. The
earliest node entry time is used for all nodes.
Before the clean-up process runs, it checks the system clock on the node where it is
running against the last time it ran. If more than three days elapsed since the last run,
the process sends a warning message to DSM/TC and stops.
Manual Tape File Expiration
You do not have to wait for DSM/TC to run the tape file expiration process
automatically. You can run it any time, and you can specify exactly which file catalogs
the process should clean up by executing the MEDIACOM EXPIRE TAPEFILE
command.
Note. An operator sees the warning message only by executing an INFO MEDIADEFS
command or receiving an error 619 from the MEDIADBM process (see the DSM/Tape Catalog
Messages Manual). The command displays any existing warning message. When INFO
MEDIADEFS returns a warning message, the operator must decide what to do, then issue an
ALTER MEDIADEFS command with the RESET EXPIRATION option to remove the warning
message from DSM/TC.
For more information, see the INFO MEDIADEFS or ALTER MEDIADEFS command in the
DSM/T
ape Catalog Operator Interface (MEDIACOM) Manual.