Subsystem description

A subsystem description is a system object that contains information defining the characteristics of an operating environment controlled by the system. The system-recognized identifier for the object type is *SBSD. A subsystem description defines how, where, and how much work enters a subsystem, and which resources the subsystem uses to perform the work. An active subsystem takes on the simple name of the subsystem description.

Like a set of detailed blueprints, each subsystem description is unique, containing the specific characteristics that describe the subsystem. The description includes where work can enter the subsystem, how much work the subsystem can handle, how much main storage (memory) will be used, and how quickly jobs in the subsystem can run.

You can use a subsystem description supplied with your system (with or without making changes to it), or you can create your own.

• Subsystem description attributes
  Subsystem description attributes are common overall system attributes. When you create a subsystem, the first step is to define the subsystem attributes.
• Work entries
  Work entries identify the sources where jobs can enter a subsystem. Specific types of work entries are used for different types of jobs. Work entries are part of the subsystem description.
• Routing entries
  The routing entry identifies the main storage subsystem pool to use, the controlling program to run (typically the system-supplied program QCMD), and additional run-time information (stored in the class object). Routing entries are stored in the subsystem description.