Re: [gdm-list] gdm does not start and "X: client 2 rejected from local host" log message

[Brian Cameron <brian cameron oracle com>]

Simone:

> It seems I cannot issue "gdmflexiserver --command=VERSION" or
> "gdmflexiserver --version" because I'm not running gdm, btw the
> version gdm is 2.20.5 (packaged as 2.20.5-0ubuntu3 under ubuntu 8.04
> lts).

Okay, so you are using the "old" GDM.  GDM 2.21 was rewritten, and
configuration is different.

> > Try editing /etc/gdm/custom.conf and add a line that says "Enable=true"
> > after the line that says "[debug]" so it looks like this:
> >
> > [debug]
> > Enable=true
> >
> > Then reboot or restart GDM, and let the failure occur.  This will
> > generate more verbose debug messages in your syslog (either
> > /var/log/messages or /var/adm/messages depending on your system).
> > Do these debug messages highlight what might be going on?
>
> I enabled debug and restarted gdm. My /var/log/messages is an empty
> file; I found gdm's logs in /var/log/daemon ( I added my
> /var/log/daemon as attachment).

Looking at this logfile, I do not see any XDMCP messages which indicates
that no XDMCP clients tried to connect to the the GDM server during the
time period of the logfile.  If there is an XDMCP connection issue, you
would need to provide a logfile which shows an XDMCP client trying to
connect and failing.

Looking at the log, I do see several places where there are the 
following messages

Jun  1 10:12:15 ltsp gdm[12932]: DEBUG: term_quit: Final cleanup
Jun  1 10:12:15 ltsp gdm[12932]: DEBUG: gdm_slave_quick_exit: Will kill 
everything from the display
Jun  1 10:12:15 ltsp gdm[12932]: DEBUG: gdm_server_stop: Server for :0 
going down!

This indicates that the GDM greeter is being killed soon after it
starts.  This might not be an error.  If you are actually logging in
on the console display, these messages may just be the normal behavior
of the GDM login GUI exiting after login.  Are you having problems with
the login GUI showing up on the login display?

If so, then you might check your Xorg log files to see if there is a
problem with the Xserver starting.  The Xorg logs are stored in
/var/log/Xorg* on my system, but may be in a different location on
your system.  Also, you could check the log files in /var/log/gdm.

If the GDM login GUI is not starting on the console display, this
can be caused if a library that the GDM login GUI depends on is
missing on the system or if the wrong version is installed, or if
the greeter is crashing.

If the GDM GUI is crashing, then it might be leaving behind a core
file in the root directory (/) or in /var/lib/gdm, or wherever core
files from system processes are stored on the system.  Providing
a stack trace from any such core files would help to diagnose the
problem.

> > I believe that LTSP uses XDMCP, so you may need to fine tune some
> > of the XDMCP configuration options to make things work.  Check
> > the "Configuration" section of the version of the GDM manual that
> > corresponds to the version of GDM you are using:
>
> In the past, ltsp thinclients used gdm with XDMCP to connect to remote
> ltsp-server's X; now gdm has been replaced by LDM.
> I'm using a fatclient, a system that is much more like a normal
> standalone client; it uses gdm with its own Xserver. Because it does
> not connects to a remote X using xdmcp, I don't think that xdmcp can
> help.

How do the clients connect to the GDM server if they are not using
XDMCP?

Brian