Previously, it has been pointed out how the commands to control DFSMShsm are structured for the example system. In the text that follows, the example system is used to describe what DFSMShsm does in the process of automatic availability management. Dump and backup are shown as two separate processes that contribute to total availability management.
The example system uses cartridge-type tape units in single-file mode for backup volumes. Also, the example system always selects scratch volumes because there are no volumes identified to DFSMShsm as dump or backup tape volumes and all partial tapes are marked full when they are demounted. The example system defers requests for tape mounts until OPEN processing for the data set occurs. These parameter selections minimize interference with other DFSMShsm functions when a tape mount is requested.