From owner-freebsd-stable@FreeBSD.ORG Thu Jan 28 16:25:57 2010 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 10AE7106568B; Thu, 28 Jan 2010 16:25:57 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id D3EC78FC18; Thu, 28 Jan 2010 16:25:56 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id 7FEA246B0D; Thu, 28 Jan 2010 11:25:56 -0500 (EST) Received: from jhbbsd.localnet (smtp.hudson-trading.com [209.249.190.9]) by bigwig.baldwin.cx (Postfix) with ESMTPA id C896F8A01F; Thu, 28 Jan 2010 11:25:55 -0500 (EST) From: John Baldwin To: Dimitry Andric Date: Thu, 28 Jan 2010 11:23:33 -0500 User-Agent: KMail/1.12.1 (FreeBSD/7.2-CBSD-20100120; KDE/4.3.1; amd64; ; ) References: <1264680406.2869.72.camel@balrog.2hip.net> <4B618270.3050309@andric.com> In-Reply-To: <4B618270.3050309@andric.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201001281123.33097.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0.1 (bigwig.baldwin.cx); Thu, 28 Jan 2010 11:25:55 -0500 (EST) X-Virus-Scanned: clamav-milter 0.95.1 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-2.5 required=4.2 tests=AWL,BAYES_00, SUBJECT_FUZZY_TION autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on bigwig.baldwin.cx Cc: freebsd-stable@freebsd.org, Brooks Davis , Dan Naumov , freebsd-questions@freebsd.org, Robert Noland Subject: Re: booting off GPT partitions 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: Thu, 28 Jan 2010 16:25:57 -0000 On Thursday 28 January 2010 7:26:24 am Dimitry Andric wrote: > On 2010-01-28 13:06, Robert Noland wrote: > > John or Marcel can correct me, but I don't think that this is an issue. > > The bootstrap is located in the pmbr in sector 0 and the GPT headers and > > tables are in sectors 1 - 34. The bootstrap code knows how to read the > > GPT tables and can deal with> 2 tb lba's. > > Ah yes, I see it now. It uses EDD packets with the BIOS int 13 > interface, which apparently have a 64-bit LBA. This should support up > to 8 ZiB with 512-byte sectors... > > OTOH, I have no idea how well most BIOSes actually implement this. > Since many OSes simply don't support anything over 2^32 sectors, I would > not be amazed to find much BIOSes out there that behave the same. Or am > I too paranoid now? :) It should work fine. The GPT boot code was originally written specifically to supporting booting from RAID volumes > 2TB. I've tested it on mfi(4) volumes that large (though I didn't verify the individual LBAs of all the various bits read in by the bootstrap and loader were). I know that other folks ran into bugs until the ZFS GPT boot code was all made 64-bit clean and that they have since booted > 2TB ZFS volumes ok. -- John Baldwin