I have two similar NetBSD boxes, one is under 9_STABLE and the other is
old 8_STABLE. Sometimes one or another or even both get hit by something
and OS freezes. It looks like hardware stops working, but OS do not
catch panic. It means if ping is constantly running on console it would
look like network went down. Any command or logging in would hang forever
like it happens when disk do not respond.
It can happen daily or not happen within month and this often happens around
certain time of day, what looks very mysterious. I have replaced hardware and
this changed nothing so I believe it hit software bug.
I have remote serial console to one of the boxes and it respond to break
so I can fall into gdb. I would like to know what I can do for starters
to start investigating this problem from gdb and/or from system.