SDDM
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The Simple Desktop Display Manager (SDDM) is the preferred display manager for KDE Plasma desktop. From Wikipedia:
- Simple Desktop Display Manager (SDDM) is a display manager (a graphical login program) for the windowing systems X11 and Wayland. SDDM was written from scratch in C++11 and supports theming via QML. It is the successor of the KDE Display Manager and is used in conjunction with KDE Frameworks 5, KDE Plasma 5 and KDE Applications 5.
Installation
Install the sddm package from the official repositories.
Then follow Display manager#Loading the display manager to start SDDM at boot. If you're migrating from KDM, the following should work for you:
# systemctl disable kdm && systemctl enable sddm
Removed symlink /etc/systemd/system/display-manager.service. Created symlink from /etc/systemd/system/display-manager.service to /usr/lib/systemd/sddm.service.
Configuration
The configuration file for SDDM can be found at /etc/sddm.conf
. See man sddm.conf
for all options.
On systems controlled by systemd, everything should work out of the box, since SDDM defaults to using systemd-logind
for session management. The configuration file will therefore not be created at package installation time. SDDM offers a command for generating a sample configuration file with the default settings if you really want one:
# sddm --example-config > /etc/sddm.conf
Autologin
SDDM supports automatic login through its configuration file, for example:
/etc/sddm.conf
[Autologin] User=john Session=plasma.desktop
This configuration causes a KDE Plasma session to be started for user john
when the system is booted. Available session types can be found in /usr/share/xsessions/
directory.
An option to autologin into KDE Plasma while simultaneously locking the session is not available as of the time of this writing.
You can add a little script that activates the screensaver of KDE to the autostart as a workaround:
#!/bin/bash /usr/bin/qdbus-qt4 org.kde.screensaver /ScreenSaver SetActive true & exit 0
Theme settings
Theme settings can be changed in the [Theme]
section.
Main theme
Set the main theme through the Current
value, e.g. Current=archlinux
.
Mouse cursor
To set the mouse cursor theme, set CursorTheme
to your preferred cursor theme.
Changing your avatar
You can simply put a png image named username.face.icon
into the default directory /usr/share/sddm/faces/
. Alternatively you can change the default directory to match your desires, e.g. FacesDir=/var/lib/AccountsService/users/
.
Numlock
If you want to enforce Numlock to be enabled, set Numlock=on
in the [General]
section.
Configuration GUI
- KDE Frameworks' System Settings contains an SDDM configuration module.
- There is a Qt-based sddm-config-editor in the AUR.
Troubleshooting
No desktop effects in KDE Plasma
When I changed from KDM to SDDM and logged into KDE Plasma 4, desktop effects were disabled and could not be enabled. It turned out that SDDM wrongly started KDE Plasma in Failsafe mode. If you cannot enable desktop effects, log out and check the session selection in SDDM before logging back in.
SDDM starts on tty1 instead of tty7
SDDM follows the systemd convention of starting the first graphical session on tty1. If you prefer the old convention where tty1 through tty6 are reserved for text consoles, add the following to your sddm.conf
:
/etc/sddm.conf
[XDisplay] MinimumVT=7
One or more users don't show up on the greeter
SDDM only displays users with a UID in the range of 1000 to 65000 by default, if the UIDs of the desired users are below this value then you will have to modify this range. Modify your sddm.conf
to (for a UID of 501, say):
/etc/sddm.conf
[Users] HideShells=/sbin/nologin,/bin/false # Hidden users, this is if any system users fall within your range, see /etc/passwd on your system. HideUsers=git,sddm,systemd-journal-remote,systemd-journal-upload # Maximum user id for displayed users MaximumUid=65000 # Minimum user id for displayed users MinimumUid=500 #My UID is 501