Subject: Re: CVS commit: src/sys/kern
To: Reinoud Zandijk <reinoud@netbsd.org>
From: Manuel Bouyer <bouyer@antioche.eu.org>
List: source-changes
Date: 01/28/2006 19:10:00
On Sat, Jan 28, 2006 at 07:02:44PM +0100, Reinoud Zandijk wrote:
> On Sat, Jan 28, 2006 at 11:51:19AM +0000, Darren Reed wrote:
> > I'm quite dismayed that it is so hard to get information about a panic
> > out of NetBSD.  Writing a crash dump doesn't appear to work (where the
> > dump space is the same as swap) and nearly every time there is a panic,
> > the system faults again in ddb, either locking ddb and the system up
> > or just preventing you from getting what you need.
> 
> I'm sorry to say but i have to agree with Darren here. I'm using and have 
> used several architectures running NetBSD but the i386 is on of the worst 
> on crash information recovering. This is part due to the stated lack of 
> messagebuffer survival and the wierd kernel coredump saving in the swap 
> space. If the swap space is not twice the amount of memory in the machine 
> dumping a kernel core is impossible.

That's not my experience, I have swap space sightly greather than
physical memory and it's enough.


> What would be better is a mechanism 
> that either revovers kernel coredumps _before_ the swap is turned on or a 
> mechanism that allows the swapper to recognize kernel coredumps so it can 
> spare the dump as long as possible.

Ho, is your problem that the swap space is erased again before getting
the core dump ? If so you probably have a small amount of memory.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--