Explanation: DUPLEX allows DFSMShsm to create two tapes
concurrently, the original tape intended to be kept onsite and the
alternate tape taken offsite or written to a remote tape library.
| Subparameter |
Explanation |
|---|
| BACKUP(Y|N) |
Duplex alternates will or will not
be made for backup volumes. If this subparameter is not specified,
no change will be made to the current setting for backup. Y specifies
that duplexing will occur for backup tape volumes. N specifies that
duplexing will not occur for backup tape volumes.If
BACKUP(Y) is specified, then the ERRORALTERNATE subparameter can also
be specified: - BACKUP(Y ERRORALTERNATE(CONTINUE))
- Specifies that if an error occurs on the alternate volume, then
the processing will continue on the original tape. This is the default
if neither CONTINUE nor MARKFULL are specified.
Upon completion
of the original tape, either a tapecopy or a recycle is immediately
attempted, according to the following subparameter:
- BACKUP(Y ERRORALTERNATE(CONTINUE(TAPECOPY)))
- A TCN record for tapecopy is created and written to OCDS. The
TCN record indicates that TAPECOPY should be used to create the duplex
tape. This is the default if neither TAPECOPY nor RECYCLE are specified.
- BACKUP(Y ERRORALTERNATE(CONTINUE(RECYCLE)))
- A TCN record for recycle is created and written to OCDS. The TCN
record indicates that the original volume should be recycled in order
to create new original and duplex tapes.
|
| MIGRATION(Y|N) |
Duplex alternates will or will not
be made for migration volumes. If this subparameter is not specified,
no change will be made to the current setting for migration. Y specifies
that duplexing will occur for migration tape volumes. N specifies
that duplexing will not occur for migration tape volumes. If MIGRATION(Y)
is specified, then the ERRORALTERNATE subparameter can also be specified: - MIGRATION(Y ERRORALTERNATE(CONTINUE))
- Specifies that if an error occurs on the alternate volume, then
the processing will continue on the original tape. This is the default
if neither CONTINUE nor MARKFULL are specified.
Upon
completion of the original tape, either a tapecopy or a recycle is
immediately attempted, according to the following subparameter:
- MIGRATION(Y ERRORALTERNATE(CONTINUE(TAPECOPY)))
- A TCN record for tapecopy is created and written
to OCDS. The TCN record indicates that TAPECOPY should be used to
create the duplex tape. This is the default if neither TAPECOPY nor
RECYCLE are specified.
- MIGRATION(Y ERRORALTERNATE(CONTINUE(RECYCLE)))
- A TCN record for recycle is created and written
to OCDS. The TCN record indicates that the original volume should
be recycled in order to create new original and duplex tapes.
- MIGRATION(Y ERRORALTERNATE(MARKFULL))
- Specifies that both the original and alternate tapes will be marked
full if an error occurs on the alternate tape and the failing data
set will be retried on a new set of tapes.
|
SMS relationship: Parameter has the same meaning when applied
to SMS-managed or non-SMS-managed DASD volumes or data sets.
SETSYS default: When either BACKUP or MIGRATION is specified
with no subparameter, the default is Y.
DFSMShsm default: If you do not specify DUPLEX and either
of its subparameters, DUPLEXING does not occur.
Note: The SETSYS DUPLEX command is not saved across DFSMShsm startups,
therefore, it is recommended that you specify the SETSYS DUPLEX command
in your DFSMShsm startup member so that duplexing will be your normal
environment. Although the SETSYS DUPLEX values can be changed while
DFSMShsm is up and running, the values will not take effect until
after any currently running function has completed.