Disable GUI
 

How do you disable the GUI (X server?) in Linux for server machines that don't require anything but a command-line interface? I'm a newbie but I've read about runlevel 3 - is running it in runlevel 3 the standard way of disabling GUI for production servers?

Also, how can you remove the GUI functionality so that you can't do startx or start up the GUI or X server in any way, because I wouldn't want the option to start the X server on a production machine?

Thanks.

First, edit /etc/inittab and change whatever the current runlevel is and change it to the one you need (I won't give the numbers as I think some distros have different numbers to others). This will stop your OS from booting into GUI by default.

Then uninstall Xorg and KDE or Gnome or whatever your GUI is with your package manager.

I would simply not install the GUI to begin with. I prefer a slim server containing ONLY the basics necessary for operation and the additional daemons for the servers purpose..

This is simple to achieve with Debian, and Ubuntu Server, just don't select desktop environment during install. I would imagine RHEL / CentOS can't be much different, I would think there would be an option during install to install or not install the GUI.

RedHat if I recall runlevel 3 is without GUI and runlevel 5 is with GUI.

http://www.redhat.com/docs/manuals/e...utdown-rl.html

All of the default installations of RHEL include GNOME.

You can install without X or GNOME by customizing the package selections and removing those options from the list.

If you've already installed all of it, you can use the Add/Remove Software option in the menu to get rid of GNOME from Desktop Environment set and X Window System from the Base System set.

If disk space isn't an issue, you could also just boot to runlevel 3 and then chmod /usr/bin/startx to 700. That will remove all users' permissions to that command, except root. This would probably be the quickest and least intrusive option.

Unfortunately it might not be quite that simple. Ubuntu, for instance, gives you two choices: What we normally expect to be runlevel 5 and what we normally expect to be runlevel 1.

Ubuntu, IIRC (I don't have my laptop in front of me) starts you in what it calls runlevel 2, which is runlevel 5. If you change to runlevel 5, you get the same thing.

Most standard and reliable way (I think) would be for the poster to set runlevel 3 then edit the /etc/rc3.d directory (wherever that actually is on his distr) to make sure the display manager is removed and won't start.

startx is just a script that calls xinit to start X. So chmod on startx will not help that much against knowledgable users.

Out of curiosity, is it possible to 'disable' a runlevel - in particular 5, maybe perhaps 2 and 4?

If you know that you'll only ever use 0,1,6 for maintenance activities and 3 for actually running it, could you do away with 2, 4, and 5? I ask out of curiosity about Linux rather than practical purposes - though if there is a way, I might consider the option.

True enough, but "knowledgeable users" would also be able to just boot into single user mode and reset the root password. Then they'd do whatever they want anyway. And if you're worried about that, then removing the GUI isn't going to do you much good.

If this indeed is a security related question, then I think running a GUI interface is very low on the priority list.