System Startup, Configuration, and Shutdown Reference Manual (32650-90892)

20 Chapter1
Introduction
What Is System Shutdown?
What Is System Shutdown?
System shutdown refers to stopping the computer’s software, operating system, and other
programs. (Stopping system activity makes the computer inaccessible to users.) A system
shutdown does not imply turning off power to the computer hardware.
How System Shutdown is Carried Out
Shutdown procedures are performed by the system console command:
CTRLA
=SHUTDOWN
The =SHUTDOWN command logs off all remaining sessions, including the session logged on at
the console. All system processes are stopped in an orderly manner. Completing all system
activity and processing before shutdown, maintains the integrity of all system tables and
directories.
Shutting down the system consists of several steps:
telling users well in advance of a planned shutdown
warning users a few minutes before the shutdown
preventing anyone from starting a new job or session, or printing new reports
clearing the backlog of reports before the shutdown
answering any console requests
shutting open communication lines
suspending or aborting any jobs, and aborting sessions
entering the =SHUTDOWN command
Chapter 9 , “Halting System Activity,” outlines detailed procedures for shutting down the
system.