System Data Administration

You can use special macros to modify the data management capabilities of the operating system:

Direct Access Device Space Management (DADSM): DADSM provides exit routines that control space allocation on DASD volumes. However, you can improve storage management by using ACS routines instead of the exits.
Execute Channel Program (EXCP): You use the EXCP access method to establish your own system for organizing, storing, and retrieving data based on device characteristics.

Related reading: For more information on DADSM exit routines and EXCP macro instructions, see z/OS DFSMSdfp Advanced Services.