Considerations on image copy extension

OAE can extend both the DEDB area and the image copies of the area in a single job step. OAE extends the size of the image copy data sets that are created before the area extension by inserting dummy SDEP CIs in the extended portion. By extending the image copies, you can later use the extended image copies to recover the DEDB area.

To extend an image copy data set, the following conditions must be met:

  • The image copy must be registered in the RECON data sets.
  • The DD statements that specify the target extended image copy data sets must be coded in the JCL stream.
  • Only the SDEP portion of the area is extended.

OAE can extend the primary image copy, the secondary image copy, or both.

Review the following considerations before you extend image copies with OAE:
  • OAE extends the latest image copy data set that is registered in the RECON data sets. If the image copy data set is written on a tape volume, you must mount the tape volume.
  • OAE can extend the image copy that is compressed with compression routine FABJCMPx, which is provided by IMS HP Image Copy.
  • OAE cannot extend IC2 image copies that are created by the IMS Database Image Copy 2 Utility (DFSUDMT0). Also, OAE cannot extend image copies that are created by the flash copy process.
  • For shadow expansion, if the size of the target area data set is the same as the size of the original area data set, image copy data sets of the area can be used for recovery without having them extended. Therefore, when the size is the same, OAE does not extend the image copy data set.
  • If both the primary image copy and the secondary image copy are registered in the RECON data sets and if OAE extends only one of them due to an error, OAE invalidates the image copy that is not extended in the RECON data sets to maintain consistency.