DSM/Tape Catalog User's Guide

Introduction to DSM/TC
DSM/Tape Catalog User’s Guide — 520233-008
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Append Capable Pools
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Manual:
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Change status to FULL to prevent the tape from being used as an assigned
tape until some future time.
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Change the status to BAD to prevent the tape from being used as a scratch
tape.
Usually pools are defined with an AUTOSCRATCH value that permits immediate use of
their tapes after the tapes’ files expire. However, for special cases, pools can be
defined so that tapes with expired files receive a status of released. A released tape
cannot be used for input tape requests, and it cannot be used as a scratch tape until
an operator changes the entry’s status to scratch using the ALTER TAPEVOLUME
command.
A pool whose tapes change from a status of ASSIGNED to RELEASED could be a
pool used for confidential data. For example, a pool named EMP_PAYROLL is a pool
that contains the tapes used for a payroll application. After the files expire on an
EMP_PAYROLL tape, the tape’s status changes to released, and it is stored in another
city for three months. After three months, the tape returns, the operator erases data,
stores the tape in a scratch tape rack, and changes the tape’s entry to SCRATCH
using the ALTER TAPEVOLUME command. If you forget to change the tape’s entry
before storing the tape, DSM/TC never selects it as a scratch tape from the
EMP_PAYROLL pool.
When a tape of label type BACKUP returns to a status of SCRATCH, its tapeformat
value no longer applies and it may be used as an output tape for either the BACKUP
(T9074) or BACKCOPY utilities or Backup and Restore 2.0 Backup.
Included or Excluded From the System Search Space
To manage tapes properly, there should be no duplicate tape names on any nodes that
DSM/TC manages (the DSM/TC system). The system search space is an important
feature of DSM/TC that guards against duplicate tape names across all volume
catalogs in the system.
A pool defined as INCLUDED is protected against duplicate tape names. A pool
defined as EXCLUDED risks having a duplicate tape name cataloged in it or the
names of its tapes cataloged in other pools and volume catalogs. Create tape pools
with the ADD POOL command as included pools. For more information on system
search space, see DSM/TC System Terms on page 1-16.
Append Capable Pools
The APPEND pool attribute can be set ON or OFF:

When APPEND is OFF for a pool, the objects behave as in pre-G06.11 RVUs.
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When APPEND is ON, the objects behave differently with respect to tape volumes
of label type BACKUP that are known to the pool.