Controlling spool partitioning

JES2 defaults to assigning track groups for jobs evenly across all available spool volumes. If one volume fails, many jobs can be lost. The FENCE parameter on the SPOOLDEF initialization statement and the $T SPOOLDEF command control spool partitioning. When a specific job reaches its fencing limit, additional volumes are assigned only if there are insufficient track groups available on the volumes to which the job is fenced.

Note: If you change the FENCE specification, the new specification is checkpointed and carried across a restart of JES2 unless you perform a cold start. The FENCE specification can only be changed on a cold start or by a $T SPOOLDEF command.