Set up automatic class selection (ACS) routines as the single point of library control for filtering data sets to library resident tapes and devices. When DFSMShsm requests a tape device allocation from the z/OS operating system, ACS routines are invoked and the tape data set name, unit type, and DFSMShsm started task job name are passed to the routines. This information is used by the ACS routines to provide a storage class and a tape storage group that are associated with a tape library.

Tip: Use duplex processing to route original and alternate tapes to different locations simultaneously.

For more information about setting up ACS routines, refer to z/OS DFSMSdfp Storage Administration. For more information about duplex processing and ACS routines, see Creating concurrent tapes for on-site and offsite storage.