Adding a spare RECON data set

IMS normally works with two active RECON data sets. If one RECON data set becomes unavailable, a spare RECON data set will be activated, if a spare is available.

Recommendation: For both online and batch, use dynamic allocation for RECON data sets, and run with at least three RECON data sets.
Note: The spare data set must be in VSAM CREATE mode.

Procedure

  1. Delete the cluster.
  2. Compile DFSMDA macro for the spare data set or add DD statement in IMS JCL and batch JCL if you do not use dynamic allocation.