Changing the OLDS mode from dual to single

You must change your OLDSDEF specification in the LOGGER section of the DFSDFxxx member in IMS.PROCLIB to change the OLDS mode from dual to single. IMS initialization requires that at least three OLDSs be available for a single logging environment. You must also reconsider data set placement.

Changing the mode from single to dual or from dual to single requires changes in the following operating procedures:

  • Skeletal JCL for archive (ARCHJCL member)
  • Skeletal JCL for log recovery (LOGCLJCL member)
  • Batch JCL for Log Recovery utility
  • Batch backout JCL for online transactions and BMPs

Procedure

  1. Shut down IMS.
  2. Archive all OLDSs.
  3. Scratch the old primary OLDS data sets, and reallocate the new ones. The old primary OLDS data sets will be used as such if they are not reallocated.
  4. Delete the OLDS records from the RECON data sets, using the DELETE.LOG command.
  5. Change OLDSDEF specification to single.
  6. Change IMS startup procedure (OLDS DD statements), if required.
  7. Compile DFSMDA macros, if required.
  8. Modify operating procedures.
  9. Restart IMS.