Subsystems, job queues, and memory pools

You can control work on the system by working with the resources used to process jobs. Subsystems, job queues, and memory pools are the basic parts of work management. You can work with subsystems and job queues to manage specific jobs or to adjust the system's work flow.

To efficiently use system resources, different types of jobs require different processing instructions and system resources. To meet this need, the operating system creates unique operating environments called subsystems. Each subsystem has a set of system resources, especially a memory pool, that determines how quickly it can process jobs. Subsystems also have unique processing instructions and, in many cases, at least one associated job queue. The job queues hold incoming jobs from the users or applications until an associated subsystem has available resources. The job then moves from its queue into the subsystem where it is processed based on the instructions and resources available to that subsystem. Finally, any output that results from job processing gets handled and routed by the instructions in the job description.

During this process, you might want to monitor a job's progress or adjust its priority. Also, if the system is having trouble processing certain types of jobs, you might need to adjust the subsystems resources.

Working with subsystems, job queues and memory pools

With System i® Navigator, you can view subsystem properties, view job queues that are in use by an active subsystem, start and stop a subsystem, and adjust memory pools. These functions are available under Work Management in System i Navigator. However, some subsystem commands are only available from the character-based interface.