MODBLKS data sets enhancement migration considerations

In IMS 15, you can change your MODBLKS data set from a partitioned data set (PDS) to a partitioned data set extended (PDSE) to store more resources. Each PDSE member can be up to 2 G in size, whereas the size of each PDS member is limited to only 16 M.

You can use one of the following options for migrating a MODBLKS data set from a PDS to a PDSE:

Apply APAR PI90417 and enable MODBLKS PDSE at the same time across an IMS warm start

These steps describe how to change a MODBLKS data set from a PDS to a PDSE by applying APAR PI90417 and defining staging, inactive, and active MODBLKS PDSE data sets across an IMS warm start (or emergency restart):
  1. Keep active, inactive, and staging MODBLKS PDS data sets for fallback.
  2. Define a differently named staging MODBLKS data set as PDSE.
  3. Define the first differently named MODBLKS data set as a PDSE.
  4. Define the second differently named MODBLKS data set as a PDSE.
  5. Perform a MODBLKS system definition to generate new resource definitions into the differently named staging MODBLKS PDSE.
  6. Run the Online Change Copy utility (DFSUOCU0) to copy the differently named staging MODBLKS PDSE members to the first differently named MODBLKS PDSE.
  7. Shut down IMS.
  8. Apply APAR PI90417.
  9. Change IMS procedure to specify the first differently named MODBLKS PDSE data set as the inactive MODBLKS data set.
  10. Warm start IMS with the first differently named MODBLKS PDSE data set as the inactive MODBLKS data set.
  11. Issue the appropriate online change command sequence to make online change to the first differently named MODBLKS PDSE data set.
  12. Perform a MODBLKS system definition to generate new resource definitions into the differently named staging MODBLKS PDSE.
  13. Run the Online Change Copy utility (DFSUOCU0) to copy the differently named staging MODBLKS PDSE members to second differently named MODBLKS PDSE.
  14. Shut down IMS.
  15. Change IMS procedure to specify the second differently named MODBLKS PDSE data set as the inactive MODBLKS data set.
  16. Warm start IMS with the second differently named MODBLKS PDSE data set as the inactive MODBLKS data set.
  17. Issue the appropriate online change command sequence to make online change to the second differently named MODBLKS PDSE data set.

Apply APAR PI90417 first, and then enable the MODBLKS PDSE data sets later

You can use the following procedure to apply APAR PI90417 first, and then enable the MODBLKS PDSE data sets later. In the following procedure, one extra IMS system restart is needed than if you both apply APAR PI90417 and enable the MODBLKS PDSE data sets at the same time.
  1. Shut down IMS.
  2. Apply APAR PI90417.
  3. Warm start IMS.
  4. Keep active, inactive, and staging MODBLKS PDS data sets for fallback.
  5. Define differently named staging MODBLKS data set as a PDSE.
  6. Define the first differently named MODBLKS data set as a PDSE.
  7. Define the second differently named MODBLKS data set as a PDSE.
  8. Perform a MODBLKS system definition to generate new resource definitions into the differently named staging MODBLKS PDSE.
  9. Run online change copy utility to copy differently named staging MODBLKS PDSE members to the first differently named MODBLKS PDSE.
  10. Shut down IMS.
  11. Change IMS procedure to specify the first differently named MODBLKS PDSE data set as the inactive MODBLKS data set.
  12. Warm start IMS with the first differently named MODBLKS PDSE data set as the inactive MODBLKS data set.
  13. Issue the appropriate online change command sequence to make online change to the first differently named MODBLKS PDSE data set.
  14. Perform a MODBLKS system definition to generate new resource definitions into the differently named staging MODBLKS PDSE.
  15. Run online change copy utility to copy differently named staging MODBLKS PDSE members to the second differently named MODBLKS PDSE.
  16. Shut down IMS.
  17. Change IMS procedure to specify the second differently named MODBLKS PDSE data set as the inactive MODBLKS data set.
  18. Warm start IMS with the second differently named MODBLKS PDSE data set as the inactive MODBLKS data set.
  19. Issue the appropriate online change command sequence to make online change to the second differently named MODBLKS PDSE data set.