From owner-freebsd-questions@FreeBSD.ORG Sun Jan 2 06:15:57 2011 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 5FCE01065673 for ; Sun, 2 Jan 2011 06:15:57 +0000 (UTC) (envelope-from xaero@xaerolimit.net) Received: from mail-ey0-f182.google.com (mail-ey0-f182.google.com [209.85.215.182]) by mx1.freebsd.org (Postfix) with ESMTP id DF5228FC17 for ; Sun, 2 Jan 2011 06:15:56 +0000 (UTC) Received: by eyf6 with SMTP id 6so5730517eyf.13 for ; Sat, 01 Jan 2011 22:15:55 -0800 (PST) Received: by 10.213.34.193 with SMTP id m1mr8402663ebd.25.1293948955575; Sat, 01 Jan 2011 22:15:55 -0800 (PST) MIME-Version: 1.0 Received: by 10.213.28.148 with HTTP; Sat, 1 Jan 2011 22:15:35 -0800 (PST) In-Reply-To: <20110102130224.O49334@sola.nimnet.asn.au> References: <20110101033922.BBE051065783@hub.freebsd.org> <20110102130224.O49334@sola.nimnet.asn.au> From: Chris Brennan Date: Sun, 2 Jan 2011 01:15:35 -0500 Message-ID: To: Ian Smith Content-Type: text/plain; charset=UTF-8 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: freebsd-questions@freebsd.org Subject: Re: a new hard-drive in a 2y/o laptop X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 02 Jan 2011 06:15:57 -0000 On Sat, Jan 1, 2011 at 10:20 PM, Ian Smith wrote: > Well, what's commonly called 'the partition table' is bytes 0x1be-1ff of > the MBR, so I was confused by your writing to sector 1 rather than 0, > but have a new theory to test, seeing Chris isn't making any progress; > this maybe a victim of the old 'slice vs partition' terminology issue. > > I think I was able to figure this part out, his meaning at least. > The bsdlabel lives in sector 1 (counting from 0) of the slice concerned, > specifically the first 0x114 (276d) bytes, in the second sector of the > boot blocks. As noted above, in unsliced disks such as memstick.img > that's sector 1 of the entire disk, but in ordinary sliced disks it's in > sector 1 of the _slice_, so if you'd used (here using Chris' ad4) > > dd if=/dev/zero of=/dev/ad4s1 oseek=1 bs=512 count=1 > > I would happily run this, but ad4s1 doesn't exist, and hasn't (that I know of), I did do oseek=0 and oseek=1 on /dev/ad4 tho and that didn't change anything, it still says it can't find /dev/ad4s1b (swap obviously) > - rather than of=/dev/ad4 - then you would indeed be zeroing out the > label, ie the 'partition table' in FreeBSD-speak. Is that perhaps what > you had to do to that 6.2 disk, which I suppose was a sliced disk? > > At 6.x (and 7.x, I think) it could have been 'dangerously dedicated' ie > unsliced .. which option has been removed in 8.x _except_ regarding the > memstick.img (appearing as /dev/daXa) .. not half confusing, eh? > > I actually noticed this today, I had issues writing 8.2BETA1 to a 2GB MicroSD card, so I used a 2.5" external hard-drive and from the fixit prompt I noticed that it wrote a 1gb partition for the BETA1 image and left the rest of the desk untouched (ann 59gb of it). > In any case, it'd be a cheap trick for Chris to try from Fixit, and > though it seems unlikely there'd be anything 'leftover' from an earlier > install, maybe earlier failure/s have left a broken bsdlabel there? > > So at this still-uninstalled stage it couldn't hurt to zero that sector, > or even the first 4KB of ad4s1 .. which is /boot/boot1 plus /boot/boot2 > (which equals /boot/boot !) before the label section gets written. ie: > > sysctl kern.geom.debugflags=16 > dd if=/dev/zero of=/dev/ad4s1 bs=512 count=8 > > will remove slice 1's boot blocks entirely, including the bsdlabel. > > cheers, Ian > > [excuse broken threading, but unless cc'd I have to reply to the digest] > I've been trying to keep you in my replies but your down-under, so I don't get your replies till after 1am my time... Anywho, it's late and I need to be up in 8hrs, hopefully this can be figured out ... I would hate for the disk to be defective in some way.