From owner-freebsd-rc@FreeBSD.ORG Fri Nov 30 02:10:03 2007 Return-Path: Delivered-To: freebsd-rc@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4B59916A419 for ; Fri, 30 Nov 2007 02:10:03 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id 30A4413C461 for ; Fri, 30 Nov 2007 02:10:03 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.14.2/8.14.2) with ESMTP id lAU2A2dp017887 for ; Fri, 30 Nov 2007 02:10:02 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.2/8.14.1/Submit) id lAU2A2i3017886; Fri, 30 Nov 2007 02:10:02 GMT (envelope-from gnats) Date: Fri, 30 Nov 2007 02:10:02 GMT Message-Id: <200711300210.lAU2A2i3017886@freefall.freebsd.org> To: freebsd-rc@FreeBSD.org From: Antony Mawer Cc: Subject: Re: conf/118255: savecore never finding kernel core dumps (rcorder problem) X-BeenThere: freebsd-rc@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Antony Mawer List-Id: "Discussion related to /etc/rc.d design and implementation." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 30 Nov 2007 02:10:03 -0000 The following reply was made to PR conf/118255; it has been noted by GNATS. From: Antony Mawer To: bug-followup@FreeBSD.org, koitsu@FreeBSD.org Cc: Subject: Re: conf/118255: savecore never finding kernel core dumps (rcorder problem) Date: Fri, 30 Nov 2007 12:30:17 +1100 There seems to be conflicting information about what constitutes the correct behaviour here. The original 4.4BSD "Unix System Manager's Manual (SMM)", found here: http://docs.freebsd.org/44doc/smm/02.config/paper-6.html Indicates the following (found under the "System dumps" heading): - Kernel dumps write from the end of swap and work backwards - The kernel uses swap from the front and works forward - This way it reduces the chance of swapping overwriting the dump during the boot process until savecore is run This somewhat more modern posting suggests that is still the case: http://unix.derkeiler.com/Mailing-Lists/FreeBSD/stable/2005-11/0703.html However the FreeBSD Developers' Handbook suggests a behaviour that does not match the current reality: http://www.freebsd.org/doc/en_US.ISO8859-1/books/developers-handbook/kerneldebug.html#EXTRACT-DUMP Can anyone speak with more authority on this...? --Antony