From owner-freebsd-hackers@FreeBSD.ORG Mon Mar 26 20:31:11 2012 Return-Path: Delivered-To: hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 53851106564A for ; Mon, 26 Mar 2012 20:31:11 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from bigwig.baldwin.cx (bigknife-pt.tunnel.tserv9.chi1.ipv6.he.net [IPv6:2001:470:1f10:75::2]) by mx1.freebsd.org (Postfix) with ESMTP id 2A26B8FC1C for ; Mon, 26 Mar 2012 20:31:11 +0000 (UTC) Received: from jhbbsd.localnet (unknown [209.249.190.124]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 85A79B966; Mon, 26 Mar 2012 16:31:10 -0400 (EDT) From: John Baldwin To: rank1seeker@gmail.com Date: Mon, 26 Mar 2012 16:29:58 -0400 User-Agent: KMail/1.13.5 (FreeBSD/8.2-CBSD-20110714-p10; KDE/4.5.5; amd64; ; ) References: <20120325.150506.135.2@DOMY-PC> <201203261017.41420.jhb@freebsd.org> <20120326.180253.607.2@DOMY-PC> In-Reply-To: <20120326.180253.607.2@DOMY-PC> MIME-Version: 1.0 Content-Type: Text/Plain; charset="windows-1250" Content-Transfer-Encoding: 7bit Message-Id: <201203261629.58303.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (bigwig.baldwin.cx); Mon, 26 Mar 2012 16:31:10 -0400 (EDT) Cc: hackers@freebsd.org Subject: Re: BUG: REL 9.0 - 'boot0cfg' fails with providers of non 512 byte sectorsize X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Mar 2012 20:31:11 -0000 On Monday, March 26, 2012 2:02:53 pm rank1seeker@gmail.com wrote: > ----- Original Message ----- > From: John Baldwin > To: freebsd-hackers@freebsd.org > Cc: rank1seeker@gmail.com, hackers@freebsd.org > Date: Mon, 26 Mar 2012 10:17:41 -0400 > Subject: Re: BUG: REL 9.0 - 'boot0cfg' fails with providers of non 512 byte sectorsize > > > On Sunday, March 25, 2012 11:05:06 am rank1seeker@gmail.com wrote: > > > I've created a vnode image (md0) with sectorsizes of 8192 and 4096 > > > > > > After installing MBR's bootcode '/boot/boot0', in provider 'md0' I did: > > > # boot0cfg -o noupdate -m 0xc md0 > > > boot0cfg: read /dev/md0: Invalid argument > > > # boot0cfg -v md0 > > > boot0cfg: read /dev/md0: Invalid argument > > > > > > If custom sectorsize isn't specifed(512 bytes), then both above CMDs will > > work. > > > > MBR bootstraps (such as boot0) assume a 512 byte sector. They won't boot > > correctly on media with a different sector size. So even if you "fixed" > > boot0cfg, you wouldn't have a bootable system. > > > > -- > > John Baldwin > > > > > Is it so? > This is also true for '/boot/mbr' file? Yes. > Well, majority of PC's are still BIOS bassed so MBR scheme is still around and there are also now HDD's with 4b sector sizes and SSD's with 4b and 8k sector sizes. > > So how does things work in those cases, without GPT? The BIOS still emulates 512 byte sectors. -- John Baldwin