Subject: Re: Am I under attack or what?
To: D'Arcy J.M. Cain <>
From: Dave Burgess <>
List: current-users
Date: 01/16/1998 19:29:50
> Thus spake Brian Buhrow
> > 	Do you have your swap enabled and working?  Do you have enough swap?
> > What you describe sounds like the typical symptom of running out of virtual
> > memory.  The kernel runs, answers ping requests, but is caught in a loop
> > looking for something to pageout to with no available space.
> swapctl -l shows:
> Device      512-blocks     Used    Avail Capacity  Priority
> /dev/sd0b       524288        8   524280     0%    0
> /dev/sd1b       524288        8   524280     0%    0
> Total          1048576       16  1048560     0%
> So that's not it.  Any other suggestions?  I'm willing to speculate and
> investigate pretty much anything at this point.

The other day, I noticed something similar.

I was building a new machine and only had 8 Meg of memory available.
I've built and used dozens of 8M NetBSD machines in the past, so I knew
it was possible.

I was working away and the system froze (similar to the way it's
described above).

Figuring it was a swap problem, I increated the amount of swap space
available to 100M (I like big hard drives :-).  I put swapctl into a
loop and let it run every second.  I started up all of the programs that
consistently froze the machine up before.  I froze up again - with
swapctl showing that I had used 'almost' 16M of swap before the freeze.

Is there some kind of swap wierdness that would cause the system to
freeze like this if the amount of swap in use was (mem) x2?

> -- 
> D'Arcy J.M. Cain <darcy@{druid|vex}.net>   |  Democracy is three wolves
>                |  and a sheep voting on
> +1 416 424 2871     (DoD#0082)    (eNTP)   |  what's for dinner.

Dave Burgess                   Network Engineer - Nebraska On-Ramp, Inc.
*bsd FAQ Maintainer / SysAdmin for the NetBSD system in my spare bedroom
"Just because something is stupid doesn't mean there isn't someone that 
doesn't want to do it...."