krs@pbhyg.PacBell.COM (Kenn Sato) (04/29/88)
We seem to have a problem that arose after we upgraded our SUN 2/170's
with logins to our serial ports.
We have SUN 2/170's with 3 Meg RAM and SUN OS 3.2 UNIX BSD 4.2 and an
extra 4 serial ports (i.e, we have ttya, ttyb, ttys0-3). Since we've
upgraded there seems to be a loss of characters coming out of the serial
ports when we login. I've actually put a datascope directly to the
serial port and monitored the output. What we saw was the login process
proceeding normally until it gets to the outputting of the /etc/motd (message
of the day). Our motd is rather large (13 lines) and for some reason as it
begins to output, XON-XOFF flow control becomes active, then NULLs begin to
appear, then the output halts. It doesn't always happen, just most of the
time. Also the NULLs are interspersed throughout the text and the flow
control doesn't seem to be the cause, just another something happening at
the time. I've checked the /etc/gettytab, /etc/ttys, /etc/ttytype, etc. and we
are running at 9600 baud. I initially suspected hardware as the culprit, but
we have three other machines displaying the same symptoms.
I've kinda worked around the login portion of the problem by using the banner
parameter in gettytab to hold most of the stuff from motd and using .hushlogin
in all the login home directories to reduce the motd output impact during the
login process. I forgot to mention that when the login process halts, a
control-D then control-C will break into the shell but it bypasses the .cshrc
and .login initialization.
Anyone have any suggestions, comments, chastizing, etc. that I might try?
Any help would be appreciated. Thanks in advance.
--
Kenn R. Sato Pacific*Bell (415) 823-1918
2600 Camino Ramon, 4E200.Q, San Ramon, CA 94583
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