X lock file

[joost@rulcmc.leidenuniv.nl (joost witteveen)]

> 
> On Thu, 16 May 1996, Carlos Carvalho wrote:
> 
> > Stephen Early (sde1000@chiark.chu.cam.ac.uk) wrote on 16 May 1996 12:45:
> >  >> e.g.  have xdm login screens on vc 3,4,5,6
> >  >Yes, it's possible. Bear in mind that it will be necessary to run an X 
> >  >server for each VC, which will take a lot of memory.
> > 
> > Isn't there a problem with the lock file?
> 
> No. The lock files exist to stop you running two servers with the same 
> display number on the same machine. When you run multiple servers, you 
> give them different display numbers.


Well, as you mention the subject: there is a problem with the lock
files, but a completely different one:

I have one server, with several diskless clients (except for one boot 
floppy). The diskless clients often get rebooted while running X, 
leaving the lock file on the server. 
Some times, the PID in the lock file is the next reboot taken by
a getty. This will cause X to refuse to start up, saying that the
X server is already running.

I'm not really sure how this should be fixed, though -- all I can think
of is comparing the inode in /proc/self/exe with 
  /proc/`cat /var/run/X?-lock`/exe
but this doesn't work if no proc is installed.

(another "fix" seems to be pressing ALT_F2 (switching VC), and
trying to start X again -- now it does start ??)

-- 
joost witteveen
            joost@rulcmc.leidenuniv.nl
          joostje@debian.org
--
Use Debian Linux!