Compressing the distribution libraries

To have SMP/E compress the distribution libraries before installing SYSMODs, you can use the COMPRESS operand on the ACCEPT command. There are two ways to specify which libraries are to be compressed:

List the specific libraries on the COMPRESS operand (including libraries that may not be affected by the ACCEPT command).
Specify ALL on the COMPRESS operand; then only libraries in which elements will be installed by this ACCEPT command are eligible for compression.

Once the libraries have been determined, actual processing depends on the library type:

For source libraries, any source that is to be replaced (not updated) by one of the SYSMODs being installed is deleted from the library.
For macro libraries, no deleting is done because the SYSMOD replacing the macro might fail, and other SYSMODs might cause assemblies that use the macro.
For data element, hierarchical file system element, and program element libraries, any data element, hierarchical file system element, or program element that is to be replaced by one of the SYSMODs being installed is deleted from the library.
For load libraries, SMP/E determines which load modules within the library contain only modules being replaced by the SYSMODs being installed. Such load modules are deleted from the library. If a load module contains a module not being replaced, that load module is not deleted.

SMP/E then calls the copy utility to do the actual compress operation.

Note: The purpose of deleting the members before compressing the library is to reclaim as much space as possible before attempting to install the SYSMODs. SMP/E processes one library at a time, first deleting members, and then compressing it.