Subject: Weird hanging problem using softcar with PPPD
To: None <netbsd-help@netbsd.org, port-i386@netbsd.org, current-users@netbsd.org>
From: Gerald C. Simmons <simmons@darykon.cet.com>
List: port-i386
Date: 08/24/1998 08:53:45
Synopsis:  softcar in ttys used in conjuction with PPPD causes system hang.
OS:	   NetBSD-1.2.1


I was bringing PPPD back up on my system when I encountered something very
odd. First, I noticed that the PPP-disconnect script always failed. It donned
on me that maybe because "softcar" wasn't specified for the port PPPD was using
(ttys,) the modem might be hanging up from a DTR drop in the middle of the
sequence. I set softcar for the port in ttys, and it seemed to resolve the
problem.

Here's the weird part. After a few hours of smooth operating, my system
appeared to just hang after a PPPD callout. The system would stay hung
for almost 15 hours, then start going again. I know this because I looked
at the system logs and stuff that CRON was supposed to perform (UUCP
callouts, daily scripts by root,) had all stopped suddenly and started going
again several hours later.

While remotely debugging the system, I had asked it to soft reboot (shutdown
-r now) around 11:00pm. When I was finally able to connect to the system, the
logs told me that the re-boot didn't occur until 8:30am the next morning.

I've only seen this kind of abrupt stalling of the system when there was a
device driver problem. I suspected the softcar change and took it out. The
system has been running fine for more than a week.

Anyone else seen anything like this?

Gerry Simmons
simmons@darykon.cet.com