JES2 uses shared direct access storage device (DASD) hardware featuresto access data on all spool volumes. A copy of the JES2 queues and other status information (for example, spool space allocation maps) is written to the checkpoint data set to facilitate a warm start, as with a single JES2 member. This information is available to all members, one at a time, as needed.

Each member in the configuration must have at least one channel path to each spool volume, and these devices must be specified as shared during MVS™ system installation.