When to use logical processing

Use logical processing for the following situations:

Data is copied to an unlike device type.
Logical processing is the only way to move data between unlike device types.
Data that may need to be restored to an unlike device is dumped.
Data must be restored the same way it is dumped. This is particularly important to bear in mind when making backups that you plan to retain for a long period of time (such as vital records backups). If a backup is retained for a long period of time, it is possible that the device type it originally resided on will no longer be in use at your site when you want to restore it. This means you will have to restore it to an unlike device, which can be done only if the backup was made logically.
Aliases of VSAM user catalogs are to be preserved during copy and restore functions.
Aliases are not preserved for physical processing.
Unmovable data sets or data sets with absolute track allocation are moved to different locations.
Multivolume data sets are processed.
VSAM and multivolume data sets are cataloged as part of DFSMSdss processing.
Data sets are deleted from the source volume after a successful dump or copy operation.
Non-VSAM and VSAM data sets are renamed after a successful copy or restore operation.
You want to rename data sets through the application program interface (API) during logical dump processing.
You want to control the percentage of space allocated on each of the output volumes for copy and restore operations.
You want to copy and convert a PDS to a PDSE or vice versa.
You want to copy or restore a data set with an undefined DSORG to an unlike device.
You want to keep together all parts of a VSAM sphere.