CA Dynam for VSE User Guide

Controlling Single and Multi-Volume POWER Offload Tapes
The following example shows the job control required to RESTORE a single
(sub)library backed up to a CA Dynam/T-controlled data set as above:
// JOB RESTORE LIBR BACKUP CREATED ABOVE
// TLBL UIN,'DATASET.NAME,H' /* CAT CONTROL WITH HOLD */
// EXEC PGM=TDYNASN
// ASSGN SYSXXX,DUMMY /* ALLOW PREOPEN CHECKING */
/*
// EXEC PGM=LIBR
RESTORE SUBLIB=XXX.XXX TAPE=SYSXXX R=Y /* SINGLE (SUB)LIB ONLY */
/*
// MTC CCC,SYSXXX /* TAPE POSITIONING */
/&
Using Non-CA Dynam/T-Controlled Files
Any LIBR tape can be produced or accessed without standard labels on
non-CA Dynam/T-controlled tapes. Release of the logical unit used by LIBR at
close must be avoided and the assignment carried over to the second and
subsequent volume (if applicable) by use of the JCL assignment.
Controlling Single and Multi-Volume POWER Offload Tapes
To use CA Dynam/T to control a POWER offload tape, a label for the DTF name
specified must be present either in system standard labels or partition labels
(standard or user) for the POWER partition. IBM issues an open for the tape if
TLBL= is specified on the POFFLOAD command. Additionally, the Z option must
be specified on the TLBL because different IBM tasks issue the open and close
for the tape.
The POFFLOAD command requires that a CUU be specified. However, to get
around pre-assigning a tape drive for use by the POFFLOAD command, use the
CA Dynam/T System option PWRCUU to define a dummy CUU to be specified
on the POFFLOAD command. This definition can be done either batch or online.
The CUU specified in the PWRCUU parameter should be a deviced up nonexistent
device.
At OPEN time, CA Dynam/T releases the assignment and AVRs an appropriate
tape if the PWRCUU was specified on the POFFLOAD command. Note that IBM
can issue an I/O after close, so if there is no output for the POFFLOAD
command to process, an I/O error can be issued. You can use the H TLBL
option to prevent this situation; however the assignment is not released, and
for CA Dynam/T VM users, the drive is not detached.
2–80 User Guide