Have you ever wanted to change the login screen on your Linux PC but were unsure about how to do it? It’s not as hard as it sounds! As it turns out, it is straightforward to swap between different login windows on Linux, with a few terminal commands. In this tutorial, we’ll go over how to change the display manager on Linux. We’ll cover GDM (Gnome Display Manager,) LXDM (LXDE Display Manager,) and SDDM.
Gnome Display Manager
GDM aka Gnome Display Manager is the DM of choice for many Linux distributions that choose to offer up Gnome Shell as their primary desktop environment. It’s modern, easy on the eyes and fast.
To set up GDM as your default display manager on Linux, you must first install it. Open up a terminal and use the commands that match your Linux OS to get it going.
sudo apt install gdm3
sudo apt-get install gdm3
sudo pacman -S gdm
sudo dnf install gdm
sudo zypper install gdm
Gnome Display Manager is done installing. The next step is to enable it on your Linux PC with the systemd init system. In a terminal window, use the systemctl enable command. Be sure to add the “f” switch, as it will automatically disable your old display manager.
sudo systemctl enable gdm.service -f
With GDM set as default, reboot your system. When it comes back online, Gnome Display Manager will be the new login manager you see.
Stop or restart GDM
For whatever reason, you may need to stop or restart the GDM login manager temporarily.
To restart GDM, do:
sudo systemctl restart gdm.service
To temporarily stop GDM (till next boot,) use the stop command.
sudo systemctl stop gdm.service
Need to turn off GDM for an extended period? Run the disable command.
sudo systemctl disable gdm.service
With GDM turned off, log out of the desktop and restart the computer. After restarting, you’ll notice the Gnome Display Manager is now a terminal prompt.
LXDE Display Manager
LXDM is the default desktop login manager for LXDE and many other lesser-known desktop environments on Linux. It is very light, and for this reason, lots of people choose to use it.
Using LXDM on your system doesn’t require LXDE or any other LXDE-related package. The display manager is entirely independent of the rest of the desktop. Install it by opening up a terminal and entering one of the commands below.
sudo apt install lxdm
sudo apt-get install lxdm
sudo pacman -S lxdm
sudo dnf install lxdm
sudo zypper install lxdm
LXDM, like all login managers, is set up on the system via systemd. Open up a terminal and enable it (with the “f” switch) to set it as your default display manager.
sudo systemctl enable lxdm -f
Reboot your Linux PC. Upon restarting, LXDM will be the new display manager on the system.
Stop or restart LXDM
Stopping LXDM is done with the stop command. Running it will allow you to stop it from running, till you reboot again temporarily.
sudo systemctl stop lxdm.service
It is also possible to reboot LXDM with the restart command.
sudo systemctl restart lxdm.service
To disable the LXDE Display Manager, run the disable command in a terminal window. Keep in mind that you must re-run the enable command to start it back up!
sudo systemctl disable lxdm.service
With LXDM disabled, reboot your Linux computer. When it loads back up, LXDM will be replaced with a terminal window.
Though not as well known, SDDM is quickly making a name for itself as the display manager of choice for Qt desktop environments. Currently, both KDE Plasma 5 and LXQt make heavy use of it, due to it’s highly customizable and configurable nature. However, anyone can use SDDM, even without a Qt-based desktop like KDE or LXQt, as it handles pretty much any desktop thrown at it.
Installing SDDM requires just the “sddm” package. Install it with one of the following terminal commands below.
sudo apt install sddm
sudo apt-get install sddm
sudo pacman -S sddm
sudo dnf install sddm
sudo zypper install sddm
To use SDDM, you must first enable it within the systemd login manager, with the “f” switch.
sudo systemctl enable sddm.service -f
Finish up the SDDM setup process by rebooting your Linux machine. When it comes back online, SDDM will greet you as the default login screen.
Stop or restart SDDM
Thanks to the power of systemd, users can reboot or stop the SDDM login manager at any time, right from the terminal. To temporarily stop SDDM from running, enter the following command into a terminal.
sudo systemctl stop sddm.service
Alternatively, reboot SDDM and restart its process on your Linux PC with the restart command.
sudo systemctl restart sddm.service
At some point, you may need to disable SDDM on your Linux PC. Like GDM and LXDM, this display manager can be turned off (upon reboot) with the disable command:
sudo systemctl disable sddm.service