Controlling JES3 spool partitions and spool data sets

Your installation defines and initializes JES3 spool partitions and spool data sets during JES3 initialization. Although some characteristics of the partitions and data sets are set at that time, you can monitor and control several aspects of how they are used in a running system.

Because proper handling of spool partitions and spool data sets is a crucial factor in the performance of any JES3 system, be very careful when modifying JES3. Be sure your system programmer has completely evaluated the impact of any update on the entire complex before making any modification.

The following characteristics of spool partitions and spool data sets are determined during JES3 initialization processing and cannot be changed unless you restart JES3 using updated JES3 initialization statements, JES3 procedure statements, or both:
  • The maximum number of spool data sets
  • The name and size of each spool data set
  • The unit and volume that contain each spool data set
  • The size and location of the single track table (STT) extents on the data sets
  • The maximum number of spool partitions
  • The name of each spool partition
  • The partition to be used as the default partition
  • The partition assigned to contain JES3 checkpoint information (initialization partition)
  • The partition(s) assigned to contain data sets in specific SYSOUT classes

The next two topics describe the characteristics of spool partitions and spool data sets that you can monitor and modify after JES3 initialization.

Parent topic: Controlling JES3 devices