BACKUP and NOBACKUP: Specifying whether you intend to use DFSMShsm backup, recovery, and dump

Explanation: BACKUP | NOBACKUP are mutually exclusive, optional parameters specifying whether you intend to use any of the following DFSMShsm functions: backup, dump, recovery, and expiring backup versions. The BACKUP parameter allows you to specify restrictions as to what kind of volumes are allowed to be used for daily backup.

The target device type used for volume backups can come from multiple sources. There are the BACKUPDEVICECATEGORY options on the BACKVOL and ADDVOL commands and there are the SETSYS BACKUP options of ANY | DASD | TAPE. The target device type can apply to the backup from SMS DASD when specified on a BACKVOL command or with the SETSYS BACKUP command. For non-SMS DASD, the target device type can be specified by any BACKVOL, ADDVOL, or SETSYS BACKUP command.

Tape Library Relationship: A UNITNAME can be used for filtering in the ACS routines. If you specify the unittype for this command, it will be sent to the ACS routines in SMS for the BACKUP function.

BACKUP specifies that you intend to use some or all of the following DFSMShsm functions: backup (automatic or command), dump (automatic or command), recovery, and expire backup versions.

To do the following functions	Use this DFSMShsm command
Backup	HBACKDS, BACKDS, or BACKVOL
Automatic backup	SETSYS AUTOBACKUPSTART and DEFINE BACKUP
Dump	BACKVOL and DEFINE DUMPCLASS
Automatic dump	SETSYS AUTODUMPSTART, DEFINE DUMPCLASS, and DEFINE DUMPCYCLE
Recovery	HRECOVER or RECOVER
Expire backup versions	EXPIREBV

The SETSYS BACKUP options ANY | DASD | TAPE(unittype) are there to control the target of the backup output. The SETSYS BACKUP options apply only if the BACKUPDEVICECATEGORY option is not specified on the BACKVOL command (SMS or non-SMS) or on an ADDVOL command (non-SMS only).

Subparameter	Explanation
ANY	During volume backup processing, unless overridden by a BACKVOL command or by an ADDVOL of a non-SMS volume command, any type of daily backup volume (DASD or Tape) defined to DFSMShsm by the ADDVOL can be used for output.
DASD	During volume backup processing, unless overridden by a BACKVOL command or by an ADDVOL of a non-SMS volume command, only DASD daily backup volumes defined by the DFSMShsm ADDVOL command can be used for output.
TAPE	During volume backup processing, unless overridden by a BACKVOL command or by an ADDVOL of a non-SMS volume command, only tape daily backup volumes defined to DFSMShsm via the ADDVOL command can be used for output.
TAPE(unittype)	For volume backup processing to non-SMS tape, only tape daily backup volumes that can be mounted and written on the specified type unittype can be used for output. For SMS tape, the specified type unittype will be passed to the ACS routines. A corresponding unittype restriction for dump output can be specified with the DEFINE DUMPCLASS command. For unittype, a generic or esoteric unit name can be specified. The following generic unit names are acceptable: 3480, 3480X, 3490 and 3590-1. If an esoteric unit name is specified, it must have been previously defined to DFSMShsm using the USERUNITTABLE parameter of the SETSYS command. You specify 3480 or 3480X when you use all the functions of the 3480 or 3480X Magnetic Tape Subsystem.

Related reading: For more information, see Selecting daily backup volumes.

INUSE, with its subparameters, specifies how DFSMShsm should handle backing up a data set that is found to be in use (open for update) during volume backup processing. The following subparameters can be used with the INUSE parameter:

Subparameter	Explanation
RETRY(Y)	DFSMShsm will retry once to back up a data set if the first attempt fails because (1) the data set is in use, or (2) a BWO candidate suffers a CA/CI split and the backup is discarded.
RETRY(N)	DFSMShsm does not retry a backup if the first attempt fails because the data set is in use.
DELAY(min)	DFSMShsm delays for min minutes before retrying a backup attempt which failed because a data set was in use. For min, specify a value from 0 to 999.
SERIALIZATION (PREFERRED)	If DFSMShsm retries backing up a data set (after some delay) and finds the data set still (or again) in use, it should back up the data set anyway.
SERIALIZATION (REQUIRED)	If DFSMShsm retries backing up a data set (after some delay) and finds the data set still (or again) in use, it should fail the backup.

NOBACKUP specifies that you do not intend to use DFSMShsm backup, dump, recovery, or expire backup versions. When you specify this parameter, automatic backup and automatic dump are not run, and DFSMShsm fails any backup, dump, recovery, or expire backup versions commands.

If you specify the NOBACKUP parameter while DFSMShsm functions are running, the following will occur:

If . . .	Then . . .
Volume backup is running	The volume backup operation ends after the data set currently being processed has been backed up.
Volume dump is running	The volume dump operation ends after the volume currently being processed has been dumped.
Automatic backup is running	Automatic backup prematurely ends after all volume backup operations in process have ended.
Automatic dump is running	Automatic dump prematurely ends after all volume dump operations in process have ended.
EXPIREBV is running	EXPIREBV prematurely ends after all expire backup versions operations in process have ended.

SMS relationship: Parameter differs in meaning when applied to SMS-managed or non-SMS-managed DASD volumes or data sets.

SETSYS default: The following table describes the SETSYS BACKUP and SETSYS NOBACKUP default.

If . . .	Then . . .
You specify BACKUP without any subparameters	Any previous backup output specification and specifications for handling data sets in use are retained.
You specify RETRY without a value	The SETSYS default is N.
You specify DELAY without a value	The SETSYS default is 15.
You specify SERIALIZATION without a value	The SETSYS default is REQUIRED.

DFSMShsm default: The following table describes the SETSYS BACKUP and SETSYS NOBACKUP DFSMShsm default.

If . . .	Then . . .
You do not specify either BACKUP or NOBACKUP on any SETSYS command	The DFSMShsm default is NOBACKUP. If BACKUP has been specified but never (within this start-up of DFSMShsm) with any of the ANY \| DASD \| TAPE options specified, then the default option of ANY is used. If an option of BACKUP (either ANY \| DASD \| TAPE) has been specified already but not on this issuance of the BACKUP command, then the command is treated as if the option ANY was specified. This means that the ANY option is the default option for BACKUP.
You do not specify INUSE on any SETSYS BACKUP command	DFSMShsm does not retry any data set backup if the first attempt finds that the data set is currently in use (that is, the backup fails).
You do not specify the RETRY subparameter on any SETSYS BACKUP command	DFSMShsm does not retry any data set backup if the first attempt finds that the data set is currently in use (that is, the backup fails).
You do not specify the DELAY subparameter but you specify RETRY(Y)	DFSMShsm delays for 15 minutes before doing a retry.
You do not specify the SERIALIZATION subparameter on any SETSYS command	If DFSMShsm attempts a retry of a backup and finds the data set still in use, it will fail the backup.

Note:

If DFSMShsm has scheduled a retry of a backup, and you then change the value of the DELAY subparameter, DFSMShsm will use the most recent DELAY value to determine the time for attempting the retry.
Installation exit ARCBDEXT, if enabled, can override the RETRY and SERIALIZATION options for a given data set.
BWO data sets with CA/CI split will not be retried if SERIALIZATION(PREFERRED) has been specified.
When a backup retry is internally scheduled for a data set, it is the equivalent of a BACKDS command being issued. The settings used on the SETSYS DSBACKUP command affect where the backup is directed. Requests will be directed to tape or DASD based on the settings used in the DASDSELECTIONSIZE parameter.
If you specify BACKUP(ANY) on the SETSYS command, DFSMShsm selects the first nonfull, unallocated, daily backup volume assigned to the current day in the backup cycle. If you want DFSMShsm to use tape as a daily backup volume and you do not specify restrictions limiting the selection to tape, you must define at least one tape for each of the appropriate days in the backup cycle by using the ADDVOL command. DFSMShsm does not select a scratch tape if it cannot find any daily or unassigned, nonfull backup volumes that are already defined to DFSMShsm. If DASD daily backup volumes are not being used in your environment, specify SETSYS BACKUP(TAPE) rather than SETSYS BACKUP(ANY). This allows the flexibility of backing up to a scratch tape if an eligible daily backup volume is not found. You do not have to define tapes as daily backup volumes with the ADDVOL command if you restrict daily backup volumes to tape by:
- Specifying BACKUP(TAPE) on a SETSYS command.
- Specifying BACKUPDEVICECATEGORY(TAPE) on a BACKVOL command.
- Specifying BACKUPDEVICECATEGORY(TAPE) on the ADDVOL command of the nonSMS volume being backed up.
When daily backup volumes are restricted to the tape in one of these ways, DFSMShsm selects a scratch tape if an eligible daily backup volume is not found.