System Shutdown Procedures

System Shutdown Procedures

Many administrative tasks require the system to be shut down to a run level other than the multiuser state. This means that conventional users cannot access the system. Just before the system is taken out of the multiuser state, users on the system are requested to log off. You should do these types of tasks when they will interfere the least with the activities of the user community.

Sometimes situations arise that require the system to be taken down with little or no notice provided to the users. This is often unavoidable, but try to give at least five to fifteen minutes of notice, if possible.

At your discretion, the following actions should be prerequisites for any task that requires the system to leave the multiuser state:

When possible, perform service-affecting tasks during periods of low system use. For scheduled actions, use /etc/motd to inform users of future actions.
Check to see who is logged in before taking any actions that would affect a logged-in user. You can use the /etc/whodo, /bin/who and /usr/bsd/w commands to see who is on the system. You may also wish to check for large background tasks, such as background compilations, by executing ps -ef.
If the system is in use, provide the users advanced warning about changes in system states or pending maintenance actions. For immediate actions, use the /etc/wall command to send a broadcast message announcing that the system will be taken down at a given time. Give the users a reasonable amount of time (five to fifteen minutes) to terminate their activities and log off before taking the system down.