LightDM is a cross-desktop display manager whose aim is to be the standard display manager for the X server.
The key features (as listed by upstream) include:
- A well-defined greeter API allowing multiple GUIs.
- Support for all display manager use cases, with plugins where appropriate.
- Low code complexity.
- Fast performance.
- 1 Installation
- 2 Configuration
- 3 Tips
- 4 Troubleshooting
- 5 See also
- 6 External resources
USE flags for x11-misc/lightdm A lightweight display manager
||Enable support for Linux audit subsystem using sys-process/audit|
||Add GNOME support|
||Pull in the gtk+ greeter|
||Add support for GObject based introspection|
||Use non-root user by default|
||Add support for the Qt 5 application and UI framework|
||Enable bindings for dev-lang/vala|
emerge --ask x11-misc/lightdm
The (global) configuration file for LightDM can be found at:
The GTK greeter configuration can be modified by manually editing the following file:
The RazorQt greeter currently does not offer any configuration options.
Set LightDM as the default display manager:
To start LightDM on boot, add dbus and xdm to the default runlevel. dbus is necessary because LightDM depends on it to pass messages:
rc-update add dbus default
rc-update add xdm default
To start LightDM now:
To start LightDM on boot:
systemctl enable lightdm
To start LightDM now:
systemctl start lightdm
LightDM includes a command-line tool, dm-tool, which can be used to switch user sessions, lock the current seat, etc. To see a list of available commands, use the
For example, to lock the current seat:
Running commands at log-in
A user can run some programs automatically when logging in using LightDM by adding commands in ~/.xprofile, which will be sourced by LightDM. For example:
# Starting redshift, setting the dpi with xrandr and set the brightness to 50% with xbacklight xrandr --dpi 192 & redshift-gtk & xbacklight -set 50 &
Unlock GNOME Keyring
To unlock your GNOME Keyring (gnome-base/gnome-keyring) automatically on login, edit /etc/pam.d/lightdm to look as follows. Note: Lines ending with the comment
#keyring should be added.
auth include system-local-login auth optional pam_gnome_keyring.so #keyring account include system-local-login session include system-local-login session optional pam_gnome_keyring.so auto_start #keyring
Cursor themes not working
As of March 28, 2015, the stable versions of lightdm (lightdm-1.10.3) and lightdm-gtk-greeter (lightdm-gtk-greeter-1.7.0) have a bug that affects some DEs such as XFCE with setting the mouse cursor. Applications will apply the new mouse theme, but the root window where the window manager draws on does not. To get around this, simply unmask the latest versions (lightdm-1.13.2 and lightdm-gtk-greeter-2.0.0 at the time of writing) and the cursors will be set correctly.
More information can be found in Ubuntu's bug #1024482.
LightDM crashes upon first login if hostname changes during login
In some cases LightDM may crash when trying to log in for the first time if the hostname changes in the time between the boot and login (launchpad bug #1677058 ).
This may be encountered if net-misc/networkmanager is using the default settings to obtain the hostname from DHCP server and the hostname differs from the default one set on boot.
To disable NetworkManager hostname setting behavior, set the following line in
[main] section of /etc/NetworkManager/NetworkManager.conf:
[main] ... hostname-mode=none ...