ISC X11R3 runs out of resources, but which ones?

[Elaine Larson]

>Inevitably, after using X for a while,I lose the ability to open new
>connections to my server.  When I try to start a new application, I get, for
>example:

>       /usr2/campbell> xrdb -query
>       xrdb: No such device or address
>       xrdb: Can't open display 'unix:0'
>       /usr2/campbell>

This sounds just like the problem we were having with our SparcStations.

It turned out that our problem was caused by having our diskless SparcStations
configured so that they all shared the same /tmp.

We eventually discovered (it took a while!) that X11 creates the file
/tmp/.X11-unix/X0 (the 0 is for the screen number) on server start-up
when using unix sockets.

When someone started up their server, things worked just fine.  But because
we were sharing /tmp between workstations, when someone else started up a
server on another workstation, the first person would no longer be able
to open new connections as his or her /tmp/.X11-unix/X0 file had been
over written.

Check out server/os/4.2bsd/connection.c.  This comment is located in that
file:

#ifdef UNIXCONN
/*
 * sites should be careful to have separate /tmp directories for diskless nodes
 */

We ended up making separate /tmp space for each workstation, and that
solved the problem.  I'm not sure that this is the same problem you're
having, but it sure sounds similar.

        - Elaine Larson
          Minnesota Supercomputer Center
          elaine at msc.umn.edu