Controlling subsystem/library

1. Controlling subsystem/library, also known as QCTLSBSD, is a member of the restart category of i5/OS (TM) system values. You can use this system value to specify the controlling subsystem and the library.

Quick reference

Location In iSeries (TM) Navigator, select your system, --> Configuration and Service --> System Values --> Restart --> Setup

Special authority None

Default value Controlling subsystem - QBASE; Library - QSYS

Changes take effect At the next restart of the system

For more information on IPL, visit the information center link.
http://publib.boulder.ibm.com/infocenter/iseries/v5r3/index.jsp?topic=/rzal2/rzal2changeipl.htm

2. When the i5/OS® licensed program is first installed, QBASE is the default controlling subsystem. As the controlling subsystem, QBASE allocates system resources between the two subsystems QBASE and QSPL. Interactive jobs, communications jobs, batch jobs, and so on, allocate resources within the QBASE subsystem. Only spooled jobs are managed under a different subsystem, QSPL. This means you have less control of system resources for handling communications jobs versus interactive jobs than you would using the QCTL controlling subsystem.

Using the QCTL subsystem configuration, you have control of four additional subsystems for which the system has allocated storage pools and other system resources. Changing the QCTL subsystems, or creating your own subsystems gives you even more flexibility and control of your processing resources.