When to use physical processing

Use physical processing when the following conditions exist:

Backing up system volumes that you might want to restore with the DFSMSdss stand-alone restore program (for physical dump tapes only).
Performance is an issue.
Generally, the fastest way—measured by elapsed time—to copy or to dump an entire volume is with a physical full-volume command. This is primarily because minimal catalog searching is necessary for physical processing.
Substituting one physical volume for another or recovering an entire volume.
With a COPY or RESTORE (full-volume or track) command, the volume serial number of the input DASD volume can be copied to the output DASD volume.
Dealing with I/O errors. Physical processing provides the capability to copy, dump, and restore a specific track or range of tracks.
Dumping or copying between volumes of the same device type but different capacity.