BSD Unix machines hanging

[jeff at ntvax.UUCP]

> Symptoms: The machines appear to lock up, users cannot get characters
> echoed, console is hung. In short, the machine seems dead. The only
> way to recover is a reboot. 
> 
> However, the machine is still running in a sense. One can ping the
> machine in question, and it responds. One can open a TCP connection to
> the machine, and the connection succeeds, but hangs at that point.

We are experiencing the same symptoms about once every two weeks (average).
When the gremlin decides to assert him(her)self the terminals die one by
one when they go to disk.  Anybody running an application that doesn't
require a disk access can run forever even though every other terminal
has died (including the console).  Once they exit from that application,
they're history.  We're running 4.2 on a 780 with Massbus rm80s and an rp07.
Any ideas?

Jeff Carruth (the new guy)
North Texas State University

ihnp4!infoswx!ntvax!jeff