For 3592 devices: If your installation requires very fast access to data on a MEDIA5 or MEDIA9 tape, consider using the 3592 performance scaling feature. In DFSMShsm, performance scaling applies in both tape libraries and standalone environments.

Performance scaling uses 20% of the physical space on each tape and keeps data sets closer together and closer to the initial load point. Performance scaling permits the same amount of data to exist on a larger number of tapes, allowing more input tasks to run concurrently. With performance scaling, you can effectively increase the "bandwidth" of operations that read data in from tape.

In contrast, performance segmentation allows the use of most of the physical media, while enhancing performance for the first and last portions of the tape.

Related reading:

• For more information about implementing DFSMShsm tape environments, see z/OS DFSMSdfp Storage Administration.