Create a controlling subsystem

IBM^® supplies two complete controlling subsystem configurations: QBASE (the default controlling subsystem), and QCTL. Only one controlling subsystem can be active on the system at one time. Typically, the IBM supplied subsystem configurations should be sufficient for most business needs. However, you can create your own version of a controlling subsystem and configure it to more closely meet your company's unique needs.

Use the IBM-supplied controlling subsystem QBASE or QCTL as a model for creating your own controlling subsystem.

Note: If you create your own controlling subsystem, you should use a name other than QBASE or QCTL.

The subsystem description for the controlling subsystem should contain the following:

A routing entry containing:
- Either *ANY or QCMDI as routing data
- QSYS/QCMD as the program to be called
- Class QSYS/QCTL or a user-defined class. (This is because a user, typically the system operator, must be able to enter commands to do such things as free up storage if the auxiliary storage threshold has been reached.)
A workstation entry for the console with a type of *SIGNON (*SIGNON is a value for the AT^® parameter, specified on the Add Work Station Entry (ADDWSE) command.)
The *SIGNON value indicates that the signon display is displayed at the workstation when the subsystem is started. This requirement ensures that the subsystem has an interactive device for entry of system and subsystem level commands. The End System (ENDSYS) command ends the iSeries™ licensed program to a single session (or signon display) at the console in the controlling subsystem. A subsystem description that does not contain a workstation entry for the console cannot be started as a controlling subsystem.
An entry for another workstation:
This provides an alternative source of controlling input. If a console problem is detected during an attended IPL and the If console problem occurs (QSCPFCONS) system value is set to '1', the IPL will continue in unattended mode. Then, if the subsystem description for the controlling subsystem contains a workstation entry for another workstation, that alternate workstation can be used.
A routing entry containing:
- QSYS/QARDRIVE as the program to be called,
- and QSYS/QCTL as the class

After you have created the controlling subsystem, change the Controlling subsystem/library (QCTLSBSD) system value as follows (assuming the description is named QGPL/QCTLA):

CHGSYSVAL SYSVAL(QCTLSBSD) VALUE('QCTLA QGPL')

The change becomes effective at the next IPL.