GROUP Initialization Statement

Device pooling for job-class groups is controlled by the specification of either the DEVPOOL parameter or the device dedication positional subparameters in the EXRESC parameter. The basic difference between the two methods of dedication is that devices dedicated through the EXRESC parameter are dedicated when the group is allocated on the processor specified in the EXRESC parameter, while DEVPOOL-requested dedication is accomplished when the group is enabled on any processor. The allocation options of ANY or GROUP are used to determine whether a job that is not able to obtain all its required devices for volume mounting is allowed to go beyond the dedicated devices to satisfy its requirements. Normally, a group representing higher priority work would be allowed to go beyond the dedicated devices (ANY) if fewer than the total number required were dedicated. A group representing testing might be assigned dedicated devices to limit its impact on the throughput of production work by only allowing it to allocate dedicated devices (GROUP).