Pty problem on sun4's under SunOs 4

[Ian Dall]

We are seeing an interesting problem on our Sun 4's running SunOs 4.03.
Sometimes pty's seem to become stuck in some funny state so that anything
that tries to write to them dies. I see this most often with emacs
sub-processes but sometimes it also prevents rlogins.

The open of the pty must be returning success as that is how emacs (and I
assume most processes) knows it has found a "free" pty. The sub process
really does start (as seen from top or ps) but as soon as it does any
output it dies. The pty seems to remain in this state indefinitely and the
only hope of getting your rlogin or what ever going is to hope (or
arrange!) that another process grab that pty and hang on to it while the
desired process opens the next pty.

As far as we can tell, this is not happening on our sun 3's also running
SunOs 4. Has anyone else seen this? Is Sun doing anything about it?

 Ian Dall           life (n). A sexually transmitted disease which afflicts
                              some people more severely than others.
idall at augean.oz