[FreeNX-kNX] nxagent - unable to open display :-(

[Alastair Johnson]

On Wednesday 27 June 2007 10:29, Stefan Dirsch wrote:
> Hi
>
> I'm still struggling to get FreeNX working again on openSUSE. :-( I'm
> using the NX/FreeNX/knx packages I'm providing via the buildservice
>
>   http://software.opensuse.org/download/NX/
>
> - NX 2.1.0
> - FreeNX 0.6.0
> - knx 0.1
>
> on openSUSE 10.3 Alpha5. I've set
>
>   ENABLE_2_0_0_BACKEND="1"
>   NX_LOG_LEVEL=7
>
> in /etc/nxserver/node.conf. The client I'm using is knx.
>
>   login/password: NIS user
>   Sessiontype: UNIX/KDE
>
> Results:
> - Authenticating user: ok
> - Starting remote session: fails
>   --> xmessage window: "The connection with the remote server was shut
>       down. Please check the state of your network connection."
>
> In /var/log/nxserver.log you can see that nxagent fails with
>
> ---
> Fatal server error:
> Error: Unable to open display
> 'nx/nx,options=/suse/sndirsch/.nx/C-magellan-1000-F026663F6F267DA6E673A184B
>E033FCB/options:1000'.

You skipped the 2 preceding lines here which I think may be important. 
Info: No suitable cache file found.
Info: End of NX transport requested by signal '15'.

>
> NX> 1004 Error: NX Agent exited with exit status 1.
> NX> 596 Session startup failed.
> NX> 105 NX> 1006 Session status: closed
> rm: cannot remove directory
> `/suse/sndirsch/.nx/C-magellan-1000-F026663F6F267DA6E673A184BE033FCB/':
> Directory not empty NX> 1001 Bye.
> ---
>
> "options:1000" does not exist, whereas the directory is empty. I
> attach the complete /var/log/nxserver.log (NX_LOG_LEVEL=7). I
> redirected stdout/stderr of nxagent in nxnode, which I also attach
> (nxagent.log).

you don't need to redirect this yourself as nxnode already redirects them 
to 'session' and 'error' in the session 
directory, /suse/sndirsch/.nx/C-magellan-1000-F026663F6F267DA6E673A184BE033FCB/ 
in your example above. You just need to set SESSION_LOG_CLEAN=0 in node.conf 
to stop it removing them at the end of the session.
>
> Plain NX/NX connections via nxproxy/nxproxy and nxproxy/nxagent
> without FreeNX being involved works for me. Scripts for testing this
> are in package NX (/usr/share/doc/packages/NX/examples/samples/).

When you say plain connections word do you include starting the kde session 
using whatever command FreeNX is configured to use? See COMMAND_START_KDE in 
node.conf or if not defined there check nxloadconfig to see what's being 
used. This may not be the same as is used to start a local session.

> If you have any idea what's going wrong or you have any other proposal
> to try or see any missing informations I should provide, please let me
> know. Any help would be really appreciated.

I've not poked into that area of code since debugging a startup issue using 
0.4.0 but IIRC nxagent, kde (or other session) and something else are all 
starting in parallel, and any one of these failing would kill the other two 
as well. When this happened you would get the 'Error: NX Agent exited with 
exit status 1.' message even if nxagent wasn't the cause of the problem. I 
ended up flooding that area of nxnode with echos to a logfile to find out 
exactly what was being run, and ran every step manually to see what would 
fail. In that case it was an obscure dependency issue in the 
COMMAND_START_KDE that wasn't making it into the normal logs.
>
> Thanks,
> Stefan
>
> Public Key available
> ------------------------------------------------------
> Stefan Dirsch (Res. & Dev.)   SUSE LINUX Products GmbH
> Tel: 0911-740 53 0            Maxfeldstraße 5
> FAX: 0911-740 53 479          D-90409 Nürnberg
> http://www.suse.de            Germany
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