From owner-freebsd-stable@FreeBSD.ORG Sat Jun 4 10:05:14 2005 Return-Path: X-Original-To: freebsd-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 BCD6516A41C for ; Sat, 4 Jun 2005 10:05:14 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from cyrus.watson.org (cyrus.watson.org [204.156.12.53]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7A28143D4C for ; Sat, 4 Jun 2005 10:05:14 +0000 (GMT) (envelope-from rwatson@FreeBSD.org) Received: from fledge.watson.org (fledge.watson.org [204.156.12.50]) by cyrus.watson.org (Postfix) with ESMTP id 54C5D46B23; Sat, 4 Jun 2005 06:05:13 -0400 (EDT) Date: Sat, 4 Jun 2005 11:05:38 +0100 (BST) From: Robert Watson X-X-Sender: robert@fledge.watson.org To: Palle Girgensohn In-Reply-To: <2032FF2A928A89651F1C7843@rambutan.pingpong.net> Message-ID: <20050604110209.N84333@fledge.watson.org> References: <2032FF2A928A89651F1C7843@rambutan.pingpong.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: Brendan White , freebsd-stable@freebsd.org Subject: Re: Repeatable crash with 5.4-p1-RELEASE and SMP 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: Sat, 04 Jun 2005 10:05:14 -0000 On Sat, 4 Jun 2005, Palle Girgensohn wrote: > Anyway, I have managed to get an automatic reboot and a core dump. Giant > leap for mankind :-) . It looks kind of partly overwritten, though. > According to the Developer's handbook, the core should be saved *before* > the swap partition is added to the system. I can easily verifying that > this is not the case, the swap is "mounted" first. I once again raise > the question if PR conf/73834 shouln't be addressed? Or perhaps my core > dump is quite normal? Doesn't look like it. In rc.conf, I have: I can't speak to the crash itself, but regarding swap and cores: the problem is that fsck requires quite a lot of memory in order to operate on large file systems, so you have to configure swap before you fsck. However, you can't write the core dump to the file system until it has been fsck'd. Normally, if fsck actually uses swap, it will overwrite the core dump header, and savecore will recognize that the entire dump is invalidated, so usually you don't see the corrupted core, just that the core is missing. Whether this happens depends on how large your file systems are, how many you have (since fsck runs in parallel), and how much memory you have. If you want to be sure this doesn't happen, boot to single user mode after the crash, manually fsck without swap enabled (fsck -p), mount -a, then "sh /etc/rc.d/savecore start" to save the core. My suspicion is that the corruption you're seeing is not a property of swap being started, but it's easy to rule out if you have a reproduceable crash and can be there to boot single-user after the reboot. Robert N M Watson