Not to be confused with window manager.
A display manager is not strictly necessary, X can be started from a shell in a VT, but one can provide extra or useful funtionality.
Alphabetical list of some display managers in the official Gentoo tree:
|CDM (Console Display Manager)||x11-misc/cdm||Minimalistic display manager.|
|GDM (GNOME Display Manager)||gnome-base/gdm||DM often used with GNOME, for Wayland or X.|
|System login and authentication daemon designed for Wayland.|
|LightDM (Lightweight Display Manager)||x11-misc/lightdm||Cross-desktop display manager aiming to be the standard display manager for X.|
|LXDM (LXDE Display Manager)||lxde-base/lxdm||LXDE Display Manager.|
|Qingy (Qingy Is Not GettY)||sys-apps/qingy||A DirectFB getty replacement.|
|SDDM (Simple Desktop Display Manager)||x11-misc/sddm||Modern display manager for X11 and Wayland aiming to be fast, simple and beautiful.|
|SLiM (Simple Login Manager)||x11-misc/slim||Desktop-independent graphical display manager, fast with only a few dependencies.|
|WDM (WINGs Display Manager)||x11-misc/wdm||Modification of XDM.|
|XDM (X Display Manager)||x11-apps/xdm||X.Org's DM.|
Before setting up and using a display manager, be sure that the chosen GUI environment, startx or Wayland, works without problems. If something does not work refer to the troubleshooting guides, such as Xorg/Guide.
In all major Linux operating systems, display managers are started automatically on boot. In order for this to happen automatically a script must be added to the init system's appropriate runlevel. Examples for OpenRC and systemd are provided below.
Under most circumstances, the OpenRC init system (Gentoo's default init system) will be used to start the display manager. The following examples will set SDDM as the display manager, adjust as necessary for other display managers.
Historically, the xdm init script handled the starting of the display manager, which has now been deprecated in favor of the display-manager init script from gui-libs/display-manager-init, jump to next section for a sytem still using xdm.
If gui-libs/display-manager-init is not present, emerge it with:
emerge --ask gui-libs/display-manager-init
The configuration file should be modified to use SDDM:
To start the chosen display manager on boot, add the display-manager to the system's default runlevel:
rc-update add display-manager default
To start the display-manager immediately, run:
rc-service display-manager start
Historical use of the deprecated xdm init script
To start the chosen display manager on boot, add the xdm to the system's default runlevel:
rc-update add xdm default
To start SDDM immediately, run:
rc-service xdm start
If using systemd as the init system, first locate the chosen <display-manager>.service file.
To start SDDM on boot, enable the service:
systemctl enable sddm.service
To start SDDM immediately, run:
systemctl start sddm.service
- Xorg/Guide — explains what Xorg is, how to install it, and the various configuration options.
- X without Display Manager — describes how to start an X11 session without a display manager
- Window manager — manages the creation, manipulation, and destruction of on-screen windows and window decorations in X11.
- Desktop environment — provides a list of desktop environments available in Gentoo.
- Login — a primer which explains various aspects of a login shell.