Up to 253 volumes can be designated as spool volumes. Spool volumes are identified to JES2 by a volume serial number, the first four or five characters of which are specified by the VOLUME= parameter on the SPOOLDEF statement during JES2 initialization. The first four or five characters specifying the volume serial number of each volume must be identical to the characters specified by the VOLUME= parameter. The fifth and sixth characters can be assigned to designate individual spool volumes and can be any characters that are valid in a volume serial number.

Any volume for which the first four to five characters of the volume serial are a value matching the VOLUME= parameter value on the SPOOLDEF statement is assumed to be a spool volume and should have an allocated SYS1.HASPACE data set. If however, a SYS1.HASPACE data set is not on the volume, JES2 issues message $HASP414 and the volume is not used as a spool volume. The data set name must be SYS1.HASPACE (the default) unless the DSNAME= parameter on the SPOOLDEF statement specifies a different data set name. (see the description of SPOOLDEF in z/OS JES2 Initialization and Tuning Reference for further information on this statement, if required.)