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
USE flags for x11-misc/lightdm A lightweight display manager
||Add GNOME support||global|
||Pull in the gtk+ greeter||local|
||Use dev-libs/gobject-introspection for introspection||local|
||Pull in the kde greeter||local|
||Add support for the Qt GUI/Application Toolkit version 4.x||global|
||Add support for the Qt 5 application and UI framework||global|
emerge --ask x11-misc/lightdm
The (global) configuration file for LightDM can be found at:
The LightDM KDE greeter also provides a KCM (KDE Control Module), which appears in the System Settings under System Administration → Login Screen (LightDM).
Due to LightDM currently assuming GTK+ greeter as the default, if the KDE greeter is requested, it needs to be specified in the /etc/lightdm/lightdm.conf file:
[SeatDefaults] … greeter-session=lightdm-kde-greeter
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:
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
Usage: dm-tool [OPTION...] COMMAND [ARGS...] - Display Manager tool Options: -h, --help Show help options -v, --version Show release version --session-bus Use session D-Bus Commands: switch-to-greeter Switch to the greeter switch-to-user USERNAME [SESSION] Switch to a user session switch-to-guest [SESSION] Switch to a guest session lock Lock the current seat list-seats List the active seats add-nested-seat [--fullscreen|--screen DIMENSIONS] Start a nested display add-local-x-seat DISPLAY_NUMBER Add a local X seat add-seat TYPE [NAME=VALUE...]
For example, to lock the current seat:
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.