Control region

The IMS control region holds the control program, which continuously runs in the control region address space and controls the processing in other regions.

The IMS control region services all DL⁄I calls either directly or through the DL/I separate address space (DLISAS). The IMS control region owns all the databases that can be accessed by online application programs and is responsible for all physical input⁄output to the databases. The IMS control region supervises the processing of messages and all the communication traffic for the connected terminals. The IMS control region also manages information for restart and recovery purposes and operates the IMS system log.

The IMS control region is normally started by using the z/OS® START command. The IMS control region then automatically initiates the DBRC address space.