During initialization of an MVS™ system, the operator uses the system console or hardware management console, which is connected to the support element. From the system console, the operator initializes the system control program during the nucleus initialization program (NIP) stage.
During the NIP stage, the system might prompt the operator to provide system parameters that control the operation of MVS. The system also issues informational messages that inform the operator about the stages of the initialization process.
The LOADxx parmlib member allows your installation to control the initialization process. For example, if you specify, in LOADxx, the IEASYSxx or IEASYMxx members that the system is to use, the system does not prompt the operator for system parameters that are specified in those members; it uses the values in those members instead.
For information about the placement of LOADxx at initialization, see z/OS MVS Initialization and Tuning Reference.
For specific information on initialization procedures and the system console, see the processor operator's guide.