Disabling GNOME Desktop Manager (GDM) when Ubuntu is booting up

If you are using Ubuntu Linux system with GNOME Desktop Manager (GDM) installed, the computer will automatically go into GDM X Window GUI interface whenever it boots up.

If you prefer the computer to boot up into text console terminal interface instead of GDM, you can create a new text file /etc/init/gdm.override and put "manual" as its content.

The simplest way of doing so is to issue the command below with root access:

# echo "manual" > /etc/init/gdm.override

This works in my Ubuntu 12.04 LTS Server.