System Startup, Configuration, and Shutdown Reference Manual (32650-90907)

Chapter 1
Introduction
What Is System Shutdown?
18
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.