Thanks to all those who responded. Here's the original question:

>Environment: Sun 4/490 running SunOS 4.1 with patch 100089-04

> installed. /tmp is tmpfs, /usr/tmp -> /var/tmp -> /tmp

>

>Problem: Processes hang while swapped out. They are un-interuptible,

>and use no CPU time.

>

>These processes are frequently related to /tmp in some way. There

>have been similarly hung processes which had no clear association with

>/tmp, however, since I did not determine exactly what the hung

>processes were doing, I have not ruled out /tmp as a common factor.

>

>Often, it seems that there is a file in /tmp which hangs any process

>which tries to read from it. For instance, "cd /tmp; ls" worked, but

>"cd /tmp; ls -l" hung. This is repeatable, once it happens, I can

>hang as many processes as I want to by accessing that file.

>

>After booting, the file, the hung processes, and the problem are gone.

>I have not been able to find any way of clearing these processes other

>than booting the system.

>

>I would love a patch number, but any other advise or information will

>be appreciated. As always, email me and I'll summarize for this list.

The answer I was looking for came fromdhutches@UCSD.EDU, who said:

>Well, this is a known bug (in tmpfs) for SunOS 4.1.1. Patch number

>100174-01 will fix it. As for SunOS 4.1, I don't know, as we never

>installed it here (went straight from 4.0.3 to 4.1.1). We did see the

>exact same problem that you're seeing though (before we installed the

>patch). The 4.1.1 patch is available from princeton.edu in

>/pub/sun-fixes.

Thanks,

Charles H. Buchholtz chip@ee.upenn.edu

Systems Programmer (215) 898-2491

School of Engineering and Applied Science 200 S. 33rd St, rm 154

University of Pennsylvania Philadelphia, PA 19104