Restart system values: Controlling subsystem/library

The Controlling subsystem/library system value is also known as QCTLSBSD. You can use this system value to specify the controlling subsystem and the library.

Quick reference
Location From IBM® Navigator for i, select Configuration and Service > System Values. Right-click on Restart and click Properties, then select the Setup tab.
Special authority None.
Default value Controlling subsystem - QBASE; Library - QSYS.
Changes take effect At the next restart of the system.
Lockable No.

What can I do with this system value?

You can specify the first subsystem to start after you restart the system. One subsystem must be active while the system is running. This is the controlling subsystem. Other subsystems can be started and stopped.

If this subsystem description cannot be used (for example, it is damaged), the backup subsystem description QSYSSBSD in the library QSYS can be used. A subsystem description specified as the controlling subsystem cannot be deleted or renamed once the system is fully operational.

The subsystem description must exist in the system disk pool (also known as auxiliary storage pool) or in a basic user disk.