Creating image copy data sets for future use

You can allocate image copy data sets before you need them.

IMS automatically selects these data sets for use as output data sets when you use either of the DBRC commands GENJCL.IC or GENJCL.OIC to generate a job for the Database Image Copy utility or Online Database Image Copy utility.

Restriction: The fast replication function of the Database Image Copy 2 utility (DFSUDMT0) does not support the REUSE parameter of the INIT.DBDS command. Therefore, you cannot create data sets for the fast replication function of the Database Image Copy 2 utility before you need them.

When you use the DBRC command INIT.DBDS to identify a DBDS or area in the RECON data set, you can specify any of the following keywords for that DBDS or area:

GENMAX: Use this keyword to specify how many image copy data sets you want DBRC to maintain information about for the DBDS or area.
You can maintain a certain number of image copy data sets for physical recovery. DBRC keeps a record of a specified number of the most recent image copy data sets. This number is the value you specify for the GENMAX keyword for this DBDS; duplicate image copy data sets are not included in this number.
RECOVPD: Use this keyword to maintain data for a certain period.
REUSE: Use this keyword to inform DBRC that you want to define image copy data sets and record them in the RECON data set for future use. DBRC records these available image copy data sets, with their names, unit types, and volume serial information, in the RECON data set, selects them during the processing of a GENJCL.IC command, and uses this information in the appropriate DD name of the job for the Database Image Copy utility.
NOREUSE: Use this keyword to inform DBRC that you do not want to use an existing data set, and that you want to provide the data set name for the output image copy data set that the Database Image Copy utility is to use. Specify the data set name in either the JCL partitioned data set (PDS) member that the DBRC uses to process the GENJCL.IC command or in the job you produce. When you specify NOREUSE, DBRC dynamically sets the unit type of the output image copy data set to the default unit type for the device (as specified in the INIT.RECON and CHANGE.RECON commands).

When the Database Image Copy utility uses an available image copy data set, DBRC adds a current time stamp to its record in the RECON data set.