Difference between revisions of "LXDM"

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[[Category:Display managers]]
[[Category:Display managers]]
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LXDM is the lightweight display manager aimed to replace gdm in LXDE distros. The UI is implemented with GTK+. It is still in early stages of development.}}
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LXDM is the lightweight display manager aimed to replace gdm in LXDE distros. The UI is implemented with GTK+. It is still in early stages of development.
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Revision as of 19:12, 24 November 2013


LXDM is the lightweight display manager aimed to replace gdm in LXDE distros. The UI is implemented with GTK+. It is still in early stages of development.


The lxdm package is available in the official repositories or lxdm-gitAUR is available in the AUR.


Currently, lxdm provides an lxdm.service file. Enable it like any other systemd service:

# systemctl enable lxdm


The configuration files for LXDM are all located in /etc/lxdm/. The main configuration file is lxdm.conf, and is well documented in its comments. Another file, Xsession, is the systemwide x session configuration file and should generally not be edited. The other files in this folder are all shell scripts, which are run when certain events happen in LXDM.

These are:

  1. LoginReady is executed with root privileges when LXDM is ready to show the login window.
  2. PreLogin is run as root before logging a user in.
  3. PostLogin is run as the logged-in user right after he has logged in.
  4. PostLogout is run as the logged-in user right after he has logged out.
  5. PreReboot is run as root before rebooting with LXDM.
  6. PreShutdown is run as root before poweroff with LXDM.
Warning: The language select control in lxdm.conf is sometimes required and sometimes not. Set lang= to inverse value of itself when LXDM potentially enters a boot loop and fails to load target sessions.

Unlocking keyrings upon login

Note: lxdm 0.4.1-25 ships with /etc/pam.d/lxdm preconfigured to unlock keyrings upon login. Users no longer need to modify the file.

Adding face icons

A 96x96 px image (jpg or png) can optionally be displayed on a per-user basis replacing the stock icon. Simply copy or symlink the target image to $HOME/.face. The gnome-control-center package supplies some default icons suitable for the lxdm screen. Look under /usr/share/pixmaps/faces after installing that package.

Note: Users need not keep gnome-control-center installed to use this images. Simply install it, copy them elsewhere, and remove it.

Default session


Edit /etc/lxdm/lxdm.conf and change the session line to whatever session or DE is desired:


Example using xfce:


Example using openbox:


Example using GNOME:


This is useful for themes that have no visible session selection box, and if experiencing trouble using autologin.

Per user

To define an individual user's preferred session, simply edit his/her respective ~/.dmrc to define the selection.

Example: user1 wants xfce4, user2 wants cinnamon, and user3 wants gnome:

For user1:


For user2:


For user3:



To log in to one account automatically, without providing a password, find the line in /etc/lxdm/lxdm.conf that looks like this:


Uncomment it, substituting the target user instead of "username".

This will cause LXDM to automatically login to the specified account when it first starts up. However, if one were to log out of that account, one would have to enter its password to log back into it. To avoid this, delete the password:

$ passwd -d USERNAME 
Note: lxdm 0.4.1-25 ships with /etc/pam.d/lxdm preconfigured to allow users with empty password to log in. Users no longer need to modify the file.

Note: As with most Linux-related documentation, this is quite frequently a total lie. If the settings you make to lxdm.conf have no effect, look in /etc/lxdm for other similar configuration files. For example, some systems have /etc/lxdm/lxdm.conf -- the purpose of which is apparently only to fool you with its existence, as it is not actually read -- but *actually* use /etc/lxdm/default.conf (which may or may not be a symlink to somewhere else, like /etc/alternatives/lxdm.conf). So if the above does not work, poke around and try applying the changes to any other files you may find.

Expected logout behavior

What might be slightly surprising with LXDM is that, by default, it does not clear the last user's desktop background or kill the user's processes when that user logs out. Users desiring this behavior, can edit /etc/lxdm/PostLogout like this:


# Kills all your processes when you log out.
killall --user $USER -TERM

# Sets the desktop background to solid black. Useful if you have multiple monitors.
xsetroot -solid black
Note: This will kill daemons such as tmux, urxvtd, etc.

Users can replace killall command with the following to exclude ssh and screen processes from termination:

ps --user $USER | egrep -v "ssh|screen" | cut -b11-15 | xargs -t kill

Or to (hopefully) only kill X-Processes and childs:

ps --user $USER | cut -f1,2 -d' ' | egrep "\?$" | cut -d' ' -f1 | xargs -t kill

Another option than killall is to use loginctl:


# Terminate current user session
/usr/bin/loginctl terminate-session $XDG_SESSION_ID

# Restart lxdm
/usr/bin/systemctl restart lxdm.service
Note: Because the lxdm-binary process is part of the user session and so killed with the other processes of the session, it is required to restart the lxdm service
Note: The variable $XDG_SESSION_ID is described in the man page: pam_systemd

Shutdown and reboot commands

Shutdown and reboot commands can be configured in /etc/lxdm/lxdm.conf by adding the [cmd] section:

# reboot command
reboot=/usr/bin/systemctl reboot

# shutdown command
shutdown=/usr/bin/systemctl poweroff

Session list

To add/remove entries to LXDM's session dropdown menu; create/remove the .desktop files in /usr/share/xsessions as desired. A typical .desktop file will look something like:

[Desktop Entry]
Comment=Log in using the Openbox window manager (without a session manager)


By default, LXDM doesn't read ~/.xinitrc but ~/.xprofile. That setup is defined in the /etc/lxdm/Xsession script. The default behaviour can be adapted by modifying the Xsession file like this:



if [ -f ~/.xinitrc ]; then
  . ~/.xinitrc lxdm

exec /bin/bash -l -c "$LXSESSION"

Simultaneous users and switching users

LXDM allows multiple users to be logged into different ttys at the same time. The following command is used to allow another user to login without logging out the current user:

$ lxdm -c USER_SWITCH
Note: When the new user logs in, his/her session is now on the NEXT tty. For example, user1 logs in and issues the USER_SWITCH command. Now user2 logs in. User2 will be on tty8 while user1 will be on tty7.

If you use the Xfce desktop, the Switch User functionality of its Action Button panel item specifically looks for the gdmflexiserver executable in order to enable itself. If you provide it with an executable shell script /usr/bin/gdmflexiserver consisting of

 /usr/bin/lxdm -c USER_SWITCH

then user switching in Xfce should work fine also with LXDM.

Xscreensaver can also perform this task. For more, see the Xscreensaver#LXDM article.


After a user logs out, subsequent users have no access to PulseAudio. The reason is that PulseAudio stores server credentials as properties on the X11 root window, and since LXDM does not restart the X server, these properties are not cleaned up and prevent the sound server from starting up for the next users. To remove these properties on logout, add the following line to /etc/lxdm/PostLogout:

test -x /usr/bin/pax11publish && /usr/bin/pax11publish -r


The LXDM themes are localized in /usr/share/lxdm/themes

There is only one theme provided with LXDM, namely Industrial. To display the background file wave.svg which is part of this theme, make sure you have librsvg installed.

There are 2 themes provided with lxdm-gitAUR. ArchStripes and ArchDark. You can configure them on /etc/lxdm/lxdm.conf in theme=theme_name