Increasing the Size of the Checkpoint and Warm Start Areas

The checkpoint and warmstart areas maintain the state of spool files and saved segments between IPLs, and provide a basis for checking the integrity of the spool area without forcing a read of the entire spool space looking for valid files.

The default size of these areas on the "starter system" is 3 cylinders (left over from earlier days when VM systems were generally disk-poor), which is sufficient for a few thousand files, but many new VM systems quickly exceed these numbers and have difficulties with restarts due to missing checkpoint or warmstart data. The current maximum size of the checkpoint and warmstart areas is 10 cylinders each, which is sufficient to support hundreds of thousands of spool files, and most wise VM administrators immediately increase the size to the maximum.

See the IBM VM Planning and Installation guide for information on expanding the size of the checkpoint and warmstart areas.