ABACKUP considerations

If an instruction data set is specified in the aggregate group and DASD logging is specified, DFSMSdss is used to write the instruction data set and the activity log data set into one file on a tape (or tapes). To allow the control file to save the instruction and activity log volume serial number information, the instruction data set and activity log files must be written before the control file. Because of this restriction, the activity log written to tape does not contain volume serial number information for the control file, nor the completion code from ABACKUP processing.

In order to facilitate coexistence with previous releases of ABARS, where the control file is the first file sequence on the tape, the instruction and activity log files are written to a separate tape from the control file, if an instruction data set is specified in the aggregate group or DASD logging is specified.

The log is written to an output tape only if:

The data file has been successfully written to tape.
DASD logging has been specified at the aggregate backup site using the SETSYS ABARSACTLOGTYPE command, and the DASD activity log has been successfully processed.

If DASD logging is not specified during ABACKUP processing, the following processing takes place:

A message is written to the log indicating that DASD has not been specified for the ABACKUP process.
A blank activity log name is written to the ABR record and control file header.

The file containing the activity log data set and instruction data set has a naming convention of: prefix.I.CnnVnnnn

The parts of the activity log data set and instruction data set name are explained:

prefix: Prefix specified on the Aggregate Group Define/Alter panel.
I: Constant to identify the file as containing the instruction data set and the activity log.
Cnn: The copy number specified for ABACKUP.
Vnnnn: Version number.

If the ABACKUP activity log is being written to SYSOUT and an instruction data set has not been specified in the aggregate group definition, DFSMSdss is not called to DUMP the data sets (there will not be a tape mount request for the instruction or activity files).

After the data files are written to tape, the ABACKUP activity log (DASD only) is closed and the instruction data set and activity log are DUMPed to tape using DFSMSdss. All messages are intercepted and stored in memory during DFSMSdss processing.

After the instruction and activity log files are written to tape, the DASD ABACKUP activity log is reopened to allow the stored messages—and any additional messages—to be written to it.

Note: These additional messages are not written to the activity log file that is seen at the ARECOVER site.

The internal I/O data file for a unique copy number can be directed to DASD only if the DFSMSdss data file for the same copy number was directed to DASD, or there is no data file for this invocation of ABACKUP.

If you choose to have any or all of your ABACKUP output files directed to DASD volumes, there are special precautions you must observe for successful recovery of the backed up data:

The aggregate backup files must be properly cataloged and exist at the recovery site.
You must use the XMIT and DATASETNAME parameters on your ARECOVER command.