System Shutdown

A system shutdown does not imply turning off the power to the computer hardware. Instead, a system shutdown means stopping the computer's operating system.




	CAUTION: Normally, computer hardware remains powered on continuously. There may be instances when you must power the system down. Moving the computer and preparing for an electrical shutdown in your office are instances when you might need to power off your system.

To prepare for the system shutdown

The preparation that you need for a system shutdown depends on the number of users on your system. If you have several users and terminals, use the following steps. If you have only a few terminals and know that all activity has ceased, except for your session, you need not perform steps 1 through 9.

Step 1. Tell users about the shutdown.

Notify all users of the system about the impending system shutdown. Send a message similar to the following:

   TELL @;SYSTEM SHUTDOWN AT 11:30 AM.  PLEASE LOG OFF.

You may want to include a notice of the shutdown in the system welcome message. See the task "To create a welcome message" in the "Monitoring the System from the Console" section of this chapter.

Step 2. Prevent new system activity.

Prevent the start of new jobs and sessions and the execution of any jobs by typing the following:

   :LIMIT 0,0 Return

   :JOBFENCE 14 Return

Step 3. Send users a WARN message.

Send a warning message for users to log off immediately.

   WARN @;SHUTDOWN WILL BEGIN AT 11:30 AM.  PLEASE LOG OFF NOW.

Step 4. Clear console requests.

Display any outstanding messages at the console using the RECALL command.
:RECALL Return
Clear any pending requests with the REPLY command.
:REPLY pin number,0 Return
Assigning the ldev to zero (0), cancels the console request for the specified process identification number (pin). PINs follow the second slash (/) in the messages (requests) sent to the console.

Step 5. Abort remaining jobs.

Check to see if any jobs are active. Type in the following:
:SHOWJOB JOB=@J Return
If no jobs are active, the system responds with the following message:
NO SUCH JOBS
If there are active jobs on the system, they are listed.
Proceed to abort any remaining jobs. You may wish to wait until all executing jobs have entered the Ready state. Jobs in the Ready state can be saved to a spooler tape. To abort each job, type the following:
:ABORTJOB #Jnnn Return
Perform this step for each job listed.
To verify that the job's status has been changed, type in the following:
:SHOWJOB JOB=@J Return

Step 6. Display sessions still in progress.

List to the screen all remaining sessions still logged on to the system:

   SHOWJOB JOB=@S Return

Step 7. Send a final warning.

Send a final warning message to all remaining sessions:

   :WARN @;LOG OFF NOW!  SHUTDOWN ABOUT TO BEGIN.

Step 8. Halt any remaining sessions.

List to the screen any remaining sessions:
:SHOWJOB JOB=S@ Return
Abort all remaining sessions logged on to the system, except your own:
:ABORTJOB #Snnn Return
Perform this step for each session.
CAUTION: Do not abort the session being used by the system console.
Verify with the SHOWJOB command that the only session running on the system is that on the system console:
:SHOWJOB Return

Step 9. Save spool files.

Save any existing spool files to cassette tape. Type the following:

   :FILE T;DEV=TAPE Return

   :SPFXFER Return

   >OUTPUT @.@;*T;PURGE Return

   >EXIT Return

This action results in a tape request from the system. Respond to the tape request in the following manner:

   CTRL A 

   =REPLY pin,ldev Return

The PIN is found after the second slash (/) of the tape request. The LDEV number is the logical device number of the tape drive, generally, but not always, set at 7.

To shut the system down

Shut the system down by doing the following:

Complete, if any, system shutdown preparatory tasks.
Press Ctrl A.
At the = prompt, type SHUTDOWN and press Return.

A series of messages appears, indicating the end of the shutdown procedure. The last message ends with (Shut 6).




	CAUTION: At this point, you may push the ON/OFF button to turn the computer off. Normally, computer hardware remains powered on continuously.