DSM/Tape Catalog User's Guide

Introduction to DSM/TC
DSM/Tape Catalog User’s Guide — 520233-008
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Tape Volumes
HP recommends using APPEND ON only for tapes of label type BACKUP. APPEND is
not supported on 517x tape drives.
The APPEND pool attribute can be turned ON or OFF (default) at pool creation. For a
description of the MEDIACOM, ADD POOL command, see the DSM/Tape Catalog
Operator Interface (MEDIACOM) Manual. If a pool is created with APPEND ON, all
tape volumes of label type BACKUP added to the pool are eligible for multiple tape
files per volume set.
Previously ASSIGNED tape volumes of label type BACKUP and TAPEFORMAT
ARCHIVE residing in preexisting pools can be copied using BACKCOPY onto tape
volumes in an append capable pool. BACKCOPY is a standard Backup Restore utility.
You can alter an existing pool to APPEND ON or OFF. For a description of the
MEDIACOM, ALTER POOL command, see the DSM/Tape Catalog Operator Interface
(MEDIACOM) Manual. These rules apply:

When a preexisting pool that already contains tape volumes is altered to APPEND
ON:

All tape volumes of label type BACKUP that have a volume status of
SCRATCH are immediately eligible for append capable operations.

All tape volumes of label type BACKUP that have a volume status of
ASSIGNED are changed to FULL and cannot be reused until they expire, but
once they are made scratch tapes they are eligible for append operations.

When a preexisting pool that contains tape volumes, and was previously append
capable, is altered to APPEND OFF, all tape volumes of label type BACKUP that
have a volume status of ASSIGNED are changed to FULL to prevent future
APPEND operations.

When a preexisting pool that contains tape volumes and was previously append
capable is altered to APPEND OFF but then altered back to APPEND ON, all tape
volumes of label type BACKUP that were previously used in append operations are
returned to volume status ASSIGNED so that they are again available. Otherwise
the tape volumes remain FULL and cannot be reused until they expire.
Tape Volumes
There is a volume status for tape volumes (FULL) and a change in the meaning of
ASSIGNED tape volumes of label type BACKUP that reside in append capable pools.
These volume status differences apply:
A tape volume of label type BACKUP that resides within an append capable pool can
be altered between ASSIGNED and FULL. For a description of the MEDIACOM,
SCRATCH not used and available, same as previous.
ASSIGNED used and available for addition
al use, new behavior.
FULL used and not available, same
as previous ASSIGNED.