Subject: Re: Is this a panic or a break to ddb?
To: None <netbsd-users@netbsd.org>
From: Mark Cullen <mark.r.cullen@gmail.com>
List: netbsd-users
Date: 08/02/2006 16:36:19
Darrin Chandler wrote:
> On Wed, Aug 02, 2006 at 02:18:30PM +0100, Gavan Fantom wrote:
>> It does rather look like a break was received on the console. "comintr"
>> in the backtrace is telling here.
> 
> This hasn't happened to me, but it has come up a few different times on
> another list. Apparently it's common enough for some machines to send a
> break on shutdown, startup or both. One person was having a hard time
> figuring out what was wrong with their headless box. As long as they
> were watching via serial everything was ok, so they'd leave the cable on
> and shut down the serial "head" machine, and the headless box wouldn't
> work. Start up the "head" machine again and see ddb>! Took them a while
> before they realized the correlation.

Ouch :-)

> 
> It's easiest to get into the habit of only connecting serial when you're
> using it, or plug it into something that stays up.
> 

The problem there is the machine won't boot without the serial cable 
plugged in on the other end. Should I be out and it actually does panic, 
that would mean it would just sit there until I got back to plug the 
cable in and hit enter (it just sits at the boot prompt). I expect I 
would be getting phone calls with complaints that "the Internet isn't 
working!!!" in the mean time ;-) I don't have any other machines which 
are on an UPS either, so it's quite hard for me to do either of those at 
the moment.

I think my solution might be to just set ddb.fromconsole=0, so sending a 
break doesn't drop to ddb... I could then keep the cable plugged in to 
something permanently without worrying about it dropping to ddb? Only I 
need a longer cable to keep it in permanently.

-- 
Mark Cullen <mark.r.cullen@gmail.com>
BSc (Hons), Computer Science