dueling window managers fill disk with logging flood

[D. Hugh Redelmeier]

Binary package hint: mythbuntu-gdm-theme

On Ubuntu 9.10 + mythbuntu on AMD64 with all current updates:

My disk is filling up with messages logged in /var/log/gdm/:0-greeter.log. These messages are repeated:
 Window manager warning: Screen 0 on display ":0.0" already has a window manager; try using the --replace option to replace the current window manager.
 Window manager warning: Failed to read saved session file /var/lib/gdm/.config/metacity/sessions/1057e55ebdbfac9c126645249737304300000022070009.ms: Failed to open file '/var/lib/gdm/.config/metacity/sessions/1057e55ebdbfac9c126645249737304300000022070009.ms': No such file or directory

The infinite logging goes away once I log in, and stays away even when I log out. It seems to come back on reboot.

I think the problem is that two window managers are being started (xfwm4 and metacity). I think that this is because both have files in /usr/share/gdm/autostart/LoginWindow.

xfwm4 is started by mythbuntu-gdm-window-manager.desktop (it includes the line Exec=xfwm4) which comes from mythbuntu-gdm-theme package.

metacity is started by metacity.desktop which comes from gdm package.

Does that mean these two packages conflict?

Why does metacity thing that it wants to open that saved session file? Even the directory containing it does not exist. Creating an empty file at that path didn't fix things -- it just whined that the file was empty.

Here's some output from "ps laxgwf" while this is going on. Notice that gnome-session has started both xfwm4 and metacity.

F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND

4 0 1968 1 20 0 74936 3752 poll_s Ss ? 0:00 gdm-binary
0 0 1977 1968 20 0 76864 3796 poll_s S ? 0:00 \_ /usr/lib/gdm/gdm-simple-slave --display-id /org/gnome/DisplayManager/Display1
4 0 2001 1977 20 0 102476 21516 poll_s Ss+ tty7 12:22 \_ /usr/bin/X :0 -br -verbose -auth /var/run/gdm/auth-for-gdm-Vg1Vp3/database -nolisten tcp vt7
4 105 2207 1977 20 0 153776 6668 poll_s Ssl ? 6:50 \_ /usr/bin/gnome-session --autostart=/usr/share/gdm/autostart/LoginWindow/
0 105 2313 2207 20 0 186080 11256 poll_s S ? 2:13 | \_ gnome-power-manager
0 105 2316 2207 20 0 157448 11300 poll_s S ? 2:21 | \_ xfwm4
0 105 2319 2207 20 0 190356 17156 poll_s S ? 2:07 | \_ /usr/lib/gdm/gdm-simple-greeter
0 105 6339 2207 20 0 156072 5824 - R ? 0:00 | \_ metacity
0 0 2327 1977 20 0 57716 2624 poll_s S ? 0:00 \_ /usr/lib/gdm/gdm-session-worker

[Mario Limonciello (superm1)]

Currently we've transitioned over to lightdm on precise. SO we won't be fixing any gdm bugs with earlier releases.