GDM is the window manager for the GNOME desktop environment. GNOME is the default graphical desktop environment for Fedora and Ubuntu. The GDM window manager will be loaded automatically during the graphical installation of these operating systems. If you need to install the GNOME environment and the GDM manager, you can use the package manager by issuing a command similar to:
yum groupinstall "GNOME Desktop Environment"
The main configuration file for GDM is either gdm.conf or custom.conf, depending on the distribution of Linux. The configuration file will be located in etc/gdm/gdm.conf. This file contains sections for configuring the way the login process operates, the session environments, and the look and feel of the manager or “greeter” that the user is presented with at the initial login screen. The file is heavily commented for each section of the sections. The following is an example of this configuration file’s contents:
# For full reference documentation see the GNOME help browser under # GNOME|System category. You can also find the docs in HTML form on # http://www.gnome.org/projects/gdm/ # # NOTE: Some values are commented out, but show their default values. Lines # that begin with "#" are considered comments. # # Have fun! [daemon] # Automatic login, if true the first local screen will automatically logged # in as user as set with AutomaticLogin key. AutomaticLoginEnable=false AutomaticLogin= # Timed login, useful for kiosks. Log in a certain user after ...