In order to make better use of save volume capacity, you can have ARCHIVE compress the data before writing. Although this increases the load on the CPU, it also reduces the number of I/O operations and the number of save volumes.
Software compression by ARCHIVE is activated with the COMPRESS operand of the EXPORT and SAVE statements. No explicit specification is necessary during data restoration; ARCHIVE automatically decompresses any data compressed in the earlier save run.
Restriction:
Save files that were created with COMPRESS=YES cannot be used when installing with the software product SIR.
When saving to device types which perform hardware compression, e.g. tape cartridge devices of the type TAPE-C4, no additional software compression is carried out. For these devices, ARCHIVE assumes COMPRESS=NO.
The degree of compression varies depending on the saved files; text files, for example, are more tightly compressed than PLAM libraries.
Compression has more influence on the quantity of volumes required than on the time required for saving.