From owner-freebsd-hackers@FreeBSD.ORG  Mon Oct 27 11:02:08 2003
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Delivered-To: freebsd-hackers@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id 2660B16A4B3
	for <freebsd-hackers@freebsd.org>;
	Mon, 27 Oct 2003 11:02:08 -0800 (PST)
Received: from mail.advantagecom.net (mail.advantagecom.net [65.103.151.155])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 52D5443FB1
	for <freebsd-hackers@freebsd.org>;
	Mon, 27 Oct 2003 11:01:58 -0800 (PST)
	(envelope-from andykinney@advantagecom.net)
Received: from SCSI-MONSTER (scsi-monster.advantagecom.net [207.109.186.200])
	by mail.advantagecom.net (8.11.6/8.11.6) with ESMTP id h9RJ1ps09219;
	Mon, 27 Oct 2003 11:01:54 -0800
From: "Andrew Kinney" <andykinney@advantagecom.net>
Organization: Advantagecom Networks, Inc.
To: "Jaco van Tonder" <jacovt@cscrsa.com>,
	freebsd-hackers@freebsd.org
Date: Mon, 27 Oct 2003 11:02:17 -0800
MIME-Version: 1.0
Message-ID: <3F9CFB39.18896.330F6822@localhost>
Priority: normal
In-reply-to: <016a01c39c7a$a23a78b0$3635a8c0@jaco>
X-mailer: Pegasus Mail for Windows (v4.12a)
Content-type: text/plain; charset=US-ASCII
Content-transfer-encoding: 7BIT
Content-description: Mail message body
Subject: Re: [4.8-RELEASE - Stable, 5.1-RELEASE] Panics when system loaded
X-BeenThere: freebsd-hackers@freebsd.org
X-Mailman-Version: 2.1.1
Precedence: list
Reply-To: andykinney@advantagecom.net
List-Id: Technical Discussions relating to FreeBSD
	<freebsd-hackers.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-hackers>
List-Post: <mailto:freebsd-hackers@freebsd.org>
List-Help: <mailto:freebsd-hackers-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-hackers>,
	<mailto:freebsd-hackers-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 27 Oct 2003 19:02:08 -0000

On 27 Oct 2003 at 13:08, Jaco van Tonder wrote:

> buildworld and my machine panicked. Tried a few more times with random
> panics. Same random panics occur if I build the kernel. After a bit of
> struggling I managed to get a GENERIC kernel built with debug symbols
> on the latest source. I did not manage to build or install world on
> the new sources, but the panics happen regardless of what kernel is
> running.
> 

Last time we had random trap 12 panics, it was because we had 
some bad RAM.  The RAM wasn't bad enough to fail post, but it did 
occasionally flip bits on the data registers of one of the chips. Not all 
RAM test software can catch that, but the Dell diagnostic software 
did.

Of course the same thing can happen if your BIOS has overly 
aggressive RAM timings set.

Since your problems occurred regardless of the kernel, it would 
certainly imply a hardware problem.

Sincerely,
Andrew Kinney
President and
Chief Technology Officer
Advantagecom Networks, Inc.
http://www.advantagecom.net