Allocating an SCDS

The following access method services job allocates a 6-track SCDS.

  //STEP  EXEC PGM=IDCAMS
  //SYSUDUMP DD SYSOUT=*
  //SYSPRINT DD SYSOUT=*
  //SYSIN    DD *
    DEFINE CLUSTER(NAME(SMS.SCDS1.SCDS) LINEAR VOL(SMSV01) -
    TRK(6 6) SHAREOPTIONS(3,3)) -
    DATA(NAME(SMS.SCDS1.SCDS.DATA)REUSE)
  /*

This job creates a VSAM linear data set named SMS.SCDS1.SCDS. You can combine the DEFINE commands for all your allocations into the same job step, but this example shows only one for purposes of illustration. After allocating an SCDS, you define its contents through ISMF dialogs.

You should allocate an SCDS on a device shared by all systems in the SMS complex. If you allocate an SCDS on a device that is not shared by all the systems, then you can activate the SCDS only from systems that have access to it.

You should specify the REUSE option when you define an SCDS to avoid running into space problems (SMS reason code 6068) as result of subsequent SCDS updates, or IMPORT/EXPORT functions.

See z/OS DFSMS Access Method Services Commands for information on using access method services commands.