Subsystems

A subsystem is a single, predefined operating environment through which the system coordinates work flow and resource usage.

i5/OS can contain several independent operating subsystems. The run-time characteristics of a subsystem are defined in the subsystem description.

IBM supplies several subsystem descriptions that can be used with or without modification:
QINTER
Used for interactive jobs
QBATCH
Used for batch jobs
QBASE
Used for both interactive and communications batch jobs
QCMN
Used for communications batch jobs
QSERVER
Used for file server system
QSYSWRK
Used for general system work
QUSRWRK
Used to run TCP/IP server jobs that do work on behalf of a specific user.

You can also define a new subsystem using the Create Subsystem Description (CRTSBSD) command.