Re: CygwinX at MS Terminalserver?

[Jon TURNEY <jon.turney@dronecode.org.uk>]

On 13/08/2010 08:13, Steffen Sledz wrote:
> Am 12.08.2010 18:04, schrieb Jon TURNEY:
>> On 12/08/2010 08:31, Steffen Sledz wrote:
>>> Does anyone has experiences running CygwinX at an MS
>>> Terminalserver? We like to use it at one based on Windows
>>> Server 2003 with NTFS.
>>>
>>> Is it possible to run multiple XWin instances for multiple
>>> user sessions in parallel?
>>>
>>> Any suggestions how to setup the rights in /tmp, /var/log,
>>> /var/run, etc.?
>>
>> You shouldn't change the rights on any of these, as this could
>> affect the security or functioning of other cygwin apps.
>>
>> Fortunately, you shouldn't need to, as, provided each X server
>> instance has a unique display number, everything should work :-)
>
> This seems not to be right. :(
>
> Here are the results of my tests:
>
[snip]
>
> Now testuser0002 tries to start another server in parallel. This gives this error:
>
> /usr/bin/startxwin:  Resource temporarily unavailable (errno 11):  Another X server instance is running on DISPLAY :0

This is expected.  As I said, each X server instance must have a unique 
display number.

This can't possibly work any other way.  If two users both have an X server 
with display number 0, to which server should a client started with 
DISPLAY=:0.0 connect?

> Now testuser0001 stops his server by using the "Exit" item from the server menu. After this the files/dirs look like this.
[snip]
> /var/log:
> total 2316
> drwxrwxrwt+ 1 Administrator Administrators       0 Aug 13 08:54 .
> drwxr-xr-x+ 1 Administrator Administrators       0 May 17 16:21 ..
> -rw-r--r--  1 Administrator Administrators  139786 Aug 13 08:48 setup.log
> -rw-r--r--  1 Administrator Administrators 2219958 Aug 13 08:48 setup.log.full
> -rw-r--r--  1 testuser0001  Domain Users      4871 Aug 13 08:58 XWin.0.log
> ------------>snap<----------------
>
> Now testuser0002 tries to start a server. This results in an error popup:
>
> ------------>snip<----------------
> A fatal error has occured and Cygwin/X will now exit.
>
> Cannot open log file "/var/log/XWin.0.log"

This is interesting.  On my systems, /var/log has mode 777, rather than 1777.

Having the restricted deletion flag set on /var/log prevents other users from 
deleting the logfile from a previous run.

However, checking the source for setup.exe, I see that it does create /var/log 
with 1777 permissions, so how I got into this state I don't know...

I'm not sure that is right, but assuming it is intentional, I guess we need to 
create a /var/log/xwin with mode 777 and arrange for that to be the default 
logfile location

mkdir /var/log/xwin
chmod 777 /var/log/xwin
adding '-logfile /var/log/xwin/XWin.%s.log' to your xwin command line.

-- 
Jon TURNEY
Volunteer Cygwin/X X Server maintainer

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