Become superuser or assume an equivalent role.
Create the /etc/nologin file by using an editor.
# vi /etc/nologin |
Include a message about system availability.
Close and save the file.
This example shows how to notify users of system unavailability.
# vi /etc/nologin (Add system message here) # cat /etc/nologin ***No logins permitted.*** ***The system will be unavailable until 12 noon.*** |