The /etc/nologin File

The /etc/nologin File

The /etc/nologin file prevents any user from logging in. This feature of the login(1) program is designed to allow the system administrator to have the system running in full multiuser mode, but with no users logged in. This is useful when you wish to perform complete backups of the system or when you want to do some testing that may cause the operating system to halt unexpectedly. Of course, it is always best to do this sort of work during non-peak system usage hours.

To disable logins, simply create a file called nologin in the /etc directory. (You must be logged in as root to create files in /etc.) In addition to disallowing logins, the login program will display the contents of /etc/nologin when it denies access to the user. To allow logins again, simply remove the /etc/nologin file. A suggested format for the message in /etc/nologin is:

The system is unavailable for a few moments while we perform some routine maintenance. We will be done shortly and regret any inconvenience this may cause you. -Norton