Not to be confused with window manager.
A display manager, sometimes known as login manager or abbreviated as DM, presents the user with a graphical login screen to start an X server session.
More than half a dozen display managers are available in the Gentoo ebuild repository. The following is a non-exhaustive list, presented in alphabetical order:
|CDM (The Console Display Manager)||x11-misc/cdm||The Console Display Manager|
|GDM (GNOME Display Manager)||gnome-base/gdm||GNOME Display Manager|
|LightDM (A Lightweight Display Manager)||x11-misc/lightdm||A lightweight display manager|
|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||Simple Desktop Display Manager|
|SLiM (Simple Login Manager)||x11-misc/slim||Simple Login Manager|
|WDM (WINGs Display Manager)||x11-misc/wdm||WINGs Display Manager|
|XDM (X Display Manager)||x11-apps/xdm||X.Org's X Window Manager|
Before setting up and using a display manager, be sure that startx works without problems. If something does not work refer to the Xorg/Guide.
In 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 proper init system's runlevel. Examples for OpenRC and Systemd are provided below.
Be careful to read the documentation for each display manager, as slightly different configuration will be required. For more information see the respective wiki entry for the display manager of choice.
Under most circumstances the OpenRC init system (Gentoo's default init system) will be used to start the display manager. The XDM init script handles the starting of the display manager. Configuration of the conf.d file is needed to set a default display manager for the system.
The following examples will set SDDM to be the default display manager. Adjust as necessary for other display managers.
To start SDDM on boot, add the XDM init script to the system's default runlevel:
rc-update add xdm default
To start SDDM immediately, run:
service xdm start
If using systemd as the init system, first locate a .service file.
To start SDDM on boot, enable the following service:
systemctl enable sddm.service
To start SDDM immediately run this command:
systemctl start sddm.service