From owner-freebsd-current@FreeBSD.ORG Tue Dec 22 12:22:44 2009 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 208E21065696 for ; Tue, 22 Dec 2009 12:22:44 +0000 (UTC) (envelope-from serenity@exscape.org) Received: from ch-smtp01.sth.basefarm.net (ch-smtp01.sth.basefarm.net [80.76.149.212]) by mx1.freebsd.org (Postfix) with ESMTP id A2A428FC1D for ; Tue, 22 Dec 2009 12:22:43 +0000 (UTC) Received: from c83-253-248-99.bredband.comhem.se ([83.253.248.99]:52832 helo=mx.exscape.org) by ch-smtp01.sth.basefarm.net with esmtp (Exim 4.68) (envelope-from ) id 1NN3l8-0004ET-5y; Tue, 22 Dec 2009 13:22:40 +0100 Received: from [192.168.1.5] (macbookpro [192.168.1.5]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by mx.exscape.org (Postfix) with ESMTPSA id 4980E28B6F9; Tue, 22 Dec 2009 13:22:25 +0100 (CET) Mime-Version: 1.0 (Apple Message framework v1077) Content-Type: text/plain; charset=iso-8859-1 From: Thomas Backman In-Reply-To: <867hsf6xhh.fsf@ds4.des.no> Date: Tue, 22 Dec 2009 13:22:21 +0100 Content-Transfer-Encoding: quoted-printable Message-Id: <45929E18-EA48-4340-9954-683FF06B180B@exscape.org> References: <200912210600.46044.mel.flynn+fbsd.current@mailing.thruhere.net> <20091221150514.GB75616@roberto-al.eurocontrol.fr> <4B2F9877.70201@jrv.org> <867hsf6xhh.fsf@ds4.des.no> To: =?iso-8859-1?Q?Dag-Erling_Sm=F8rgrav?= X-Mailer: Apple Mail (2.1077) X-Originating-IP: 83.253.248.99 X-Scan-Result: No virus found in message 1NN3l8-0004ET-5y. X-Scan-Signature: ch-smtp01.sth.basefarm.net 1NN3l8-0004ET-5y 33f7a5d695b1e33c01fa767a463b5b6d Cc: Ollivier Robert , freebsd-current@freebsd.org, "James R. Van Artsdalen" Subject: Re: Some notes on RootOnZFS article in wiki X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 22 Dec 2009 12:22:44 -0000 On Dec 22, 2009, at 12:48 PM, Dag-Erling Sm=F8rgrav wrote: > "James R. Van Artsdalen" writes: >> Ollivier Robert writes: >>> On modern machines, system will boot from the GPT "freebsd-boot" >>> partition w/o having it active >> A correctly-written PC BIOS does not even look at (or for) a = partition >> table of any sort when booting. That's been the case for a >> quarter-century. A system that does not boot without the active bit >> set is buggy, not new vs. old. >=20 > Wrong, wrong, wrong. >=20 > Some MBRs look for the active bit, some don't. It doesn't mean = they're > buggy; it's a design decision. FWIW, ours does. >=20 > Some BIOSes *do* read the partition table; there was an issue some = years > ago with ThinkPads that froze at boot if you installed FreeBSD on them > because they misidentified the FreeBSD partition as a suspend-to-disk > partition. >=20 > DES Surely this doesn't contradict his statements in any way? He said that a correctly written *BIOS* doesn't look for at a partition = table; the fact that the FreeBSD MBR does is clearly irrelevant. I took = "system" to mean hardware/BIOS, by the way. The fact that some BIOSes do read it and freeze is obviously a bug, = further strengthening his argument that the BIOS shouldn't care about = the partition table. (I have this problem myself; I have two computers with nForce4 chipsets, = which cannot boot from GPT; if the disk channels aren't set to = "disabled" in the BIOS, it freezes on POST. You can have GPT storage = disks, if you disable the channels before plugging the disks in, but it = won't boot from a disk it doesn't find.) Regards, Thomas