One of the applications I really love for server administration is Webmin.
Although Ubuntu and others try to make their own tools for their OS, they are never as simple and easy to use as Webmin, and I know many other admins feel the same way. Here’s a screenshot of the view that faced me recently when a client asked us to look at the Moodle server they run themselves, which was not performing too well. Can you spot the problem?! I didn’t even need to go into a menu to see exactly what the issue was !