Re: NetBSD-HEAD amd64 crash

[Alan Barrett <apb%cequrux.com@localhost>]

On Mon, 30 Dec 2013, Thomas Mueller wrote:
> Subject: Re: NetBSD-HEAD amd64 refuses to build

Why does the Subject talk about a build problem when the body talks
about a crash?  I changed the Subject in thei reply.

> > My suggestion would be not to bother with the serial console, but
> > instead take a picture of the screen [...]

> I don't have a digital camera or smartphone.
>
> Besides, a digital camera would lose all the messages that raced 
> past on the screen.

You still haven't told us what messages are still visible on 
the screen.  Those are much more important than what's already 
scrolled out of view.  Lack of a camera should not prevent you 
from writing the messages down, and typing them into an email 
message.

> I tried reboot 0x100 but couldn't find where the dump was.  I 
> ran ls -rtl in /media/zip0/var and subdirectories but couldn't 
> find any messages from crash time.

The crash dump should be saved to whichever disk partition has 
been marked as a dump device, typically via swapctl(8).  The dump 
partition is usually the same as the swap partition, which is 
usually the "b" partition on your boot disk (e.g.  /dev/wd0b).

During the next boot after a crash, savecore(8) looks for a crash 
dump in the relevant raw disk partition, and copies it to a file 
in the /var/crash directory.  If the boot does not get far enough, 
then the dump will not end up in the /var/crash directory.  In 
theory, a method could be devised for using some other OS to copy 
the crash dump from the raw dump partition to a file, but I don't 
know of any suitable tool that already exists.

--apb (Alan Barrett)