Licensed program compression and decompression for central site distribution

Before you create the distribution media, consider this information about compressing and decompressing objects.

When you compress licensed programs you receive several benefits including saving storage space. When creating distribution media for central site distribution, you can leave all the licensed programs that have high usage decompressed. Or, you can distribute some of a licensed program in a compressed state and some of the program in a decompressed state.

Before you create the distribution media, consider these items:

• You can compress both IBM® objects and your own user-created objects. IBM program objects can be compressed only in the restricted state. Use the Compress Object (CPROBJ) control language command to compress objects.
• Programs (*PGM), service programs (*SRVPGM), and modules (*MODULE) automatically and permanently decompress the first time they are used.
• The first time a compressed panel (*PNLGRP), menu (*MENU), printer file (*FILE with attribute PRTF), or display file (*FILE with attribute DSPF) is used, it is temporarily decompressed. If such a temporarily decompressed object is used five times or for more than two consecutive days on the same initial program load (IPL), it is permanently decompressed.
• Usually an operation on a compressed object takes a little longer than if the object were decompressed. While a very large compressed object is decompressing, the system will send the message, Operation in progress. Please wait.

IBM recommends the following actions to help you reduce the amount of disk space used on the target systems. At the same time, these actions ensure that frequently used objects are decompressed:

• Compress everything you are sending to the target systems.
• Use the objects on the central system in the same manner they will be used on the target systems. Do so at least five times for panel groups, menus, printer files, and display files.
• If you are creating a premastering media, files on CD-ROMs cannot span volumes. Compress objects so that the resulting saved file fits on the CD-ROM.

For more information about compressing and decompressing objects, see Compressed objects and storage space.