lxdm selected causes gdm and lxdm both to run

[Jim Petersen]

Binary package hint: lxdm

I have Ubuntu 10.04 32-bit installed on my desktop PC and used "sudo apt-get install lubuntu-desktop" to add LUbuntu as a choice, since it is an older P4 2.4 MHz PC. I first selected "gdm" as my chosen login manager instead of "lxdm" in the dpkg configure screen that popped up during install of meta-package lubuntu-desktop. Later, I thought it would be nice to use "sudo dpkg-reconfigure lxdm" and select "lxdm" for a lightweight login manager. However, after rebooting, both lxdm and gdm start up, and cause various login and LXDE usage problems (once logged in), and sometimes gdm appears, sometimes lxdm. I saw by using "ps -aef | grep dm" that lxdm and gdm both were running.

If I use "sudo dpkg-reconfigure gdm" I also get the same choice of gdm or lxdm. However, setting lxdm in the dpkg setup for gdm causes the same behavior after rebooting: Both gdm and lxdm are running.

By setting back to gdm and rebooting, everything works normally again (only one login manager running), although at that point gdm is once again the chosen and running login manager.

One behavior I see when gdm and lxdm are both running is that after login to LUbuntu desktop, CPU usage is at 100% and the system is very unresponsive. Trying to open any window (e.g. lxterm) causes a flashing window and titlebar, and it's very hard to get it to close (system is almost unresponsive).

[Lionel Le Folgoc (mrpouit)]

I've experienced that when switching to lxdm as well. I think this is a bug in gdm though, that doesn't respect the default login manager chosen, and starts unconditionally.

[Jim Petersen (jpeter20)]

I've solved this issue. Upstart launches /etc/init/gdm.conf during boot, which causes a conflict with an already-running login manager such as lxdm. By simply renaming gdm.conf to gdm.conf.save, gdm doesn't get launched and lxdm is allowed to do its thing.

[Douglas Hanley (thesecretaryofwar)]

Good find. For the record, that script checks if /etc/X11/default-display-manager is /usr/sbin/gdm, so you can go that route too. I guess d-d-m is not created automatically anymore, is it deprecated?

[Chris Guiver (guiverc)]

Thank you for reporting this bug to Ubuntu.

Ubuntu 10.04 (lucid) reached end-of-life on May 9, 2013.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in.

[Launchpad Janitor (janitor)]

[Expired for lxdm (Ubuntu) because there has been no activity for 60 days.]