From owner-freebsd-stable@FreeBSD.ORG Mon Nov 19 15:14:59 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 90D0516A46C for ; Mon, 19 Nov 2007 15:14:59 +0000 (UTC) (envelope-from dk@tetsuo.karasik.eu.org) Received: from tetsuo.karasik.eu.org (tetsuo.karasik.eu.org [129.142.67.14]) by mx1.freebsd.org (Postfix) with ESMTP id 5674F13C481 for ; Mon, 19 Nov 2007 15:14:58 +0000 (UTC) (envelope-from dk@tetsuo.karasik.eu.org) Received: by tetsuo.karasik.eu.org (Postfix, from userid 1003) id F2320616980; Mon, 19 Nov 2007 16:14:39 +0100 (CET) Mime-version: 1.0 Content-type: text/plain; charset="koi8-r" Content-transfer-encoding: 8bit Keywords: 2001334874 X-Comment-To: Jeremy Chadwick Sender: dk@tetsuo.karasik.eu.org To: freebsd-stable@freebsd.org References: <20071118190159.GA12962@tetsuo.karasik.eu.org> <20071118193719.GB11901@eos.sc1.parodius.com> <84mytatzha.fsf@tetsuo.karasik.eu.org> <20071119144725.GA38145@eos.sc1.parodius.com> From: Dmitry Karasik In-Reply-To: Jeremy Chadwick's message of "Mon, 19 Nov 2007 06:47:25 -0800" Date: 19 Nov 2007 16:14:39 +0100 Message-ID: <84zlxas1wg.fsf@tetsuo.karasik.eu.org> Lines: 48 X-Mailer: Gnus v5.7/Emacs 20.7 Subject: Re: No kernel messages displayed during boot 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, 19 Nov 2007 15:14:59 -0000 Jeremy> Hmm, it looks as if the system doesn't have any indication of what Jeremy> the local console is. I would expect to see a "consolectl" listed Jeremy> under the "Configured:" section. See below for some of the output Jeremy> from our systems... Hi Jeremy, Thanks for your advice, I've started to dig deeper and deeper until I found that it was boot0 loader's fault. Strange as it sounds, it is the only plausible explanation I can think of, because of the all strange effects I've encountered. First, the problem went away when I've replaced /boot/loader with a freshly compiled one. But the interesting part was, that the change to the new loader caused a prompt for the location of /boot/loader on the next reboot (note, no -a in loader.conf!). Next reboots went just fine. The interesting stuff began when I reverted the loader back, and it worked - but again, first time it prompted the input, and worked afterwards. This pattern with flipping old and new loaders back and forth actually was reproducible, and most fun of it all, also under qemu, which I used to save time and used the same /dev/ad4 my system lives on, but in read-only mode. The fact that that action chain actually presisted between reboots in qemu on a read-only device -- I don't know, I simply have no explanation to this. As a last resort, I've re-run boot0cfg -B , and voila, everything started worked fine, and the loader prompt effect disappeared. I'm thinking that something corrupted my MBR in such a nasty way that some boot0's memory, possibly boot flags word (-a, -D etc boot_ flags found in loader.conf) , thought of having been initialized to zero, was not. I tried to look at the source of boot0, but couldn't figure out first if that's an issue here at all, and second, if that behavior would be desirable (after all, the code must be 512 bytes max). Nevertheless, that effect was really spooky - imagine a stray bit in MBR turns off whole console logging! And at last - the machine crashed when I tried to write on msdosfs mounted on /dev/md0. Apparently it wrote something it shouldn't in the MBR. And I tried to write on msdosfs while trying to figure out if my old msdosfs kernel PR #47628 is still actual under 6.2. If anyone's willing to try that, (the PR has perl script attached, http://www.freebsd.org/cgi/query-pr.cgi?pr=47628), you're very welcome. Just back up your MBR first :) -- Sincerely, Dmitry Karasik