Definite's Extractor

My findings on Life, Linux, Open Source, and so on.

Tag Archives: gdm

Quick comparison between gdm and lightdm


  • Pro:
    • Beatuiful
    • Support wayland
  • Con:
    • Does not respect xorg.conf
    • Once you turn on timed login, you are force to kiss goodbye to other DE/WM.


  • Pro:
    • Respect xorg.conf
    • If you want to use other DE/WM, you can just logout and then login with the DE/WM you choose.
  • Con:
    • Not as good looking as GDM
    • Does not yet support wayland

Add xmonad-xfce to gdm

It is easy to find instructions of how to make xfce to use xmonad as window manager. However there is no article I aware that adding a xmonad-xfce to GDM, yet keeping the original XFce.

Step by step:

As root:

  1. cd /usr/share/xsessions; cp xfce.desktop xmonad-xfce.desktop
  2. Edit xmonad-xfce.desktop and make following to change
    a. Search Xfce and replace with Xmonad-Xfce (case sensitive)
    b. Change the line Exec=…. to Exec=PREF_WM=xmonad startxfce4

As normal user:

  1. Having a a following script file, assume its name is ifvar
    VAR=$(eval echo \$${VAR_NAME})
    if [ -n "${VAR}" ]; then
    	eval ${THEN_CMD}
    	eval ${ELSE_CMD}
  2. Edit ${HOME}/.config/autostart/WM_Selector.desktop as following
    Name=WM selector
    Comment=Window manager selector
    Exec=ifvar PREF_WM "exec ${PREF_WM} &" "exec /usr/bin/xfwm4 &"
  3. Logout, you should see the xmonad-xfce in your GDM menu

Bugs may look small, but hard to fix.

Today Jens Petersen and I have tried to fix the AR PL UMing HK Light does not show properly in x86_64. In the beginning, we thought only Lin has this problem, as Jens could not reproduce the bug, and I can only reproduce the GDM part.

Nevertheless, today we want to put this bug to the end. After seeing me playing with GDM’s gconf (which does show and hide the bug). Jens thought it can be more persuasive if we can reproduce this bug on F-11 x86_64 Live USB. So we do the test. Despite our machines are only different in monitor, mine reproduced the bug while his couldn’t. After hooking on the same monitor model, his machine also reproduced the bug!

Great, shall we tell Lin to fix the bug by changing his monitor? That does not make much sense, so we continue to dig on. After a few tests, we found out that GDM, gucharmap, and gnome-menu were hit by the bug if the font size were smaller than 14, while pango-view, gnome-terminal, and gedit seems handle small font rather well.

After a few more test, Jens pointed out that bitmap mode is used with small Chinese font, and it might be cause of the problem. So he remove the /etc/fonts/conf.d/25-ttf-arphic-uming-bitmaps.conf and bling, it works. 🙂

Other workaround can be found in the comments of the bug.