GDG Support

Connect:Direct® supports sending and receiving Generation Data Set (GDS) files to a Generation Data Group (GDG) with the following stipulations:

  • Only one file (GDS) of a GDG can be referenced in a COPY step.
  • Because enqueuing is needed to ensure data integrity during transfer to the receiving node, Connect:Direct does not support allocating and reading an entire GDG through a single DD statement (GDG ALL).
  • Specify CATLG as the second and third subparameters of the DISP parameter to ensure that the Connect:Direct recovery routines use the correct GDS when RETRY and CHECKPOINT are used. For example, DISP=(NEW,CATLG,CATLG).

For more information on GDG files, see the IBM z/OS reference manuals. The z/OS MVS JCL User’s Guide (SA22-7598) contains a good explanation of GDGs, allocation, and use and includes references to additional resources.