debugging gdm

[Stephen Adler <adler stephenadler com>]

Hi guys,

I'm in a bit of a quandary. I ran a 'yum update' on my fedora 21 system
which has two nvidia k2200 cards. I'm running the nvidia closed source
driver provided by rpmfusion. After the yum update, gdm stopped working.
Basically during the booting process, the screen goes blank and after a
few minutes my PC beeps. If change the default target to multi-user and
then log in and type 'startx', the gnome desktop springs to life. When I
log out, screen goes blank, and I never get back to my command line
prompt. Then my PC beeps a few times.

So, I'm wondering if my gdm problem is related to gnome logging out when
I start gnome using the startx command as opposed to gdm starting gnome.
Therefore, I was hoping someone could give me some tips on how to debug
either gdm, or gnome, specifically when I exit gnome (i.e. click on the
logout button in the tool bar.)  The Xorg.0.log file does not seem to
have anything in it indicating that the X server crashed or anything
like that.

Previous to the 'yum update', gdm seemed to work fine. The update pulled
in a new kernel 3.18.3-201.fc21.x86_64 and a new nvidia driver,
346.35-1.fc21.x86_64.

Thanks.