JES2 can be started after the MVS™ system has been initialized. The MVS system automatically starts JES2 if your installation provides this capability. Otherwise, you must issue the START JES2 (or S JES2) command to invoke a JCL procedure in SYS1.PROCLIB that starts JES2. See z/OS MVS System Commands, SA38-0666 for a complete description of this command.

JES2 initialization is performed after JES2 has been started. Initiators will not accept work (process jobs) until JES2 initialization is complete. This presents detailed information about the JES2 start processes and describes commands you can use to stop JES2, withdraw it from the system, specify exit point characteristics, and monitor buffers.