On Fri, 4 Feb 2005 12:46:10 -0600
Dave Huang <khym@azeotrope.org> wrote:

> My AlphaPC 164 running NetBSD 2.0 just hung in that all user processes
> seemed to quit running. However, it still responded to pings, and I
> was able to break into ddb from the serial console. Any thoughts as to
> what this means, or something I can try if it happens again? I've
> already rebooted, but I believe the same thing happened a few months
> ago with a 2.0 beta.
> 
> ~#Stopped in pid 98.1 (cyberpower) at     netbsd:cpu_Debugger+0x4:        ret     z
[snip]

I've seen this hang two or three times when running network UPS tools as well,
but with an APC UPS. It can also be triggered by doing many kernel printfs
for a couple of hours when serial console is in use.

-Tobias