LIST SUBPOOLS Command Rewrite

The LIST SUBPOOLS command produces several reports regarding the organization of storage subpools within common storage and within an address space’s private area. We have recently completed a complete rewrite that allows the command to be used both in Foreign Address Space Mode (FASM) and in dump/XDC.

LIST SUBPOOLS can be used:

  • To see what subpools exist,
  • To see what their sizes, locations and usage levels are,
  • To see what their characteristics are: Executability, storage keys, real storage backing, etc,
  • To see what tasks own and share which subpools.
  • It can also be used to understand REGION= limitations for any address space and how much of a shortage it does or does not have.
  • It can also be used to understand common storage usage levels and shortages.

Recently, we have published three updates (DBC-2002B, DBC-2003B and DBC-2003D) that implement a complete rewrite of the LIST SUBPOOLS command. Internally, it no longer uses z/OS’s VSMLIST service for gathering the underlying data, thus freeing the command from that service’s limitations. In particular, LIST SUBPOOLS can now be used in Foreign Address Space Mode (FASM) and in dump/XDC.

Also, the reports emitted by the command have been revised and improved. New columns have been added:

  • showing additional information: Subpool category, real storage backing, miscellaneous other characteristics
  • And revising the way lengths and usage levels are displayed to be more human friendly

The Built-in Help for the LIST SUBPOOLS command has been thoroughly rewritten and expanded. It is now quite comprehensive.

List Subpools




Subpools owned by or Shared to TCB #3



All Instances of Subpool 0, Across All Task



Organization and Usage of JES2’s Private Areas



Common Storage Usage (including RUCSA)



List of all Current Private Area Subpools