From owner-freebsd-stable@FreeBSD.ORG Mon May 23 14:23:24 2005 Return-Path: X-Original-To: stable@freebsd.org Delivered-To: freebsd-stable@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id E572616A41C; Mon, 23 May 2005 14:23:24 +0000 (GMT) (envelope-from dan@dan.emsphone.com) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id 9817F43D1F; Mon, 23 May 2005 14:23:24 +0000 (GMT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.13.1/8.13.3) id j4NENNVR033483; Mon, 23 May 2005 09:23:23 -0500 (CDT) (envelope-from dan) Date: Mon, 23 May 2005 09:23:23 -0500 From: Dan Nelson To: Palle Girgensohn Message-ID: <20050523142323.GB16069@dan.emsphone.com> References: <1266D69ABEC58B97FBFE536F@palle.girgensohn.se> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1266D69ABEC58B97FBFE536F@palle.girgensohn.se> X-OS: FreeBSD 5.4-STABLE X-message-flag: Outlook Error User-Agent: Mutt/1.5.9i Cc: amd64@freebsd.org, stable@freebsd.org Subject: Re: savecore: first and last dump headers disagree X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 May 2005 14:23:25 -0000 In the last episode (May 23), Palle Girgensohn said: > We have an amd64 system that still experiences crashes after > installing 5.4, mostly during high loads. (It's been unstable all the > time, really; see previous posts.) > > I've added dumpdev="/dev/amrd0s2b", and some time ago I did get coredumps, > but with latest versions of the kernel, savecore does not give me a dump, > instead it says: > > savecore: first and last dump headers disagree on /dev/amrd0s2b > savecore: unsaved dumps found but not saved "savecore -vv" should print enough of both headers to let you see what's different. > Fatal trap 12: page fault while in kernel mode > cpuid = 0: apic id = 00 > fault virtual address = 0x00 > ... > trap number = 12 > panic: page fault > cpuid = 0 > boot() called on cpu#0 > Uptime: 1d23h50m36s > Dumping 2047 MB > 16 32 > -------- > The cursor sits at the position after "32". That's probably why your headers disagree :) If you put "options KDB_TRACE" in your kernel config file, it will print a small stack trace before trying to dump, which might be enough to track down the cause of the panic even without a dump. -- Dan Nelson dnelson@allantgroup.com