Initializing the RECON data set for DBRC

Before your IMS system can operate, you must initialize the RECON data set, where system log and database status are recorded.

To prepare for online operation, ensure that the RECON data set, in which system log and database status are recorded, is ready. To initialize the RECON data sets:

Procedure

  1. Define two RECON data sets (named RECON1 and RECON2) and a spare data set (named RECON3).
  2. Identify the database data sets to be tracked.
  3. Record a starting set of data set levels.

Access Method Services parameters define the VSAM KSDS data sets referenced as RECON1, RECON2, and RECON3. Then the INIT.RECON command is used to write the required header record.

Related reading: For more information about the allocation parameters, see IMS Version 15 System Administration. All three RECON data sets can be dynamically allocated.

A separate record is required for each data set of the databases that are to be controlled. The image copy, reorganization, and recovery operations call upon the current information in the RECON data set records. Using the INIT.DBDS command, you specify:

  • The database name, the data set DD name, and the relevant data set names.
  • The number and reuse characteristics of image-copy data sets that are to be maintained.
  • Indicators of how the data sets are to be allocated by the IMS system.
  • The member names of procedures to execute database utilities.

Using other commands in the INIT group creates other records for initial change accumulation, image copy, and system log data set names. For example, use the INIT.DB command to specify the share level for a database and to register a database with DBRC.

For system definition purposes you need to coordinate the entries on DATABASE macro statements, the online JCL requirements, and the database maintenance procedures.

To use IMS 15, you must have an IMS 15 RECON. Either initialize a new set of RECON data sets, or if you are migrating from an earlier release of IMS, upgrade the RECON data sets to the IMS 15 format by using the CHANGE.RECON UPGRADE command.

Important: If you modified IMS Version 10 DBRC skeletal JCL members, you can use them in IMS Version 11 and later. However, DBRC skeletal JCL members supplied with IMS Version 10 and later are not compatible with IMS Version 9 and earlier.

For information about the DBRC-related commands, see IMS Version 15 Commands, Volume 3: IMS Component and z/OS® Commands.