From owner-freebsd-current@FreeBSD.ORG Thu Jan 15 19:35:37 2009 Return-Path: Delivered-To: current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 553F61065741 for ; Thu, 15 Jan 2009 19:35:37 +0000 (UTC) (envelope-from xcllnt@mac.com) Received: from asmtpout021.mac.com (asmtpout021.mac.com [17.148.16.96]) by mx1.freebsd.org (Postfix) with ESMTP id 395268FC24 for ; Thu, 15 Jan 2009 19:35:37 +0000 (UTC) (envelope-from xcllnt@mac.com) MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Received: from sranghan-t61.jnpr.net (natint3.juniper.net [66.129.224.36]) by asmtp021.mac.com (Sun Java(tm) System Messaging Server 6.3-7.03 (built Aug 7 2008; 32bit)) with ESMTPSA id <0KDJ00M9U2EY2C40@asmtp021.mac.com> for current@freebsd.org; Thu, 15 Jan 2009 11:35:23 -0800 (PST) Message-id: From: Marcel Moolenaar To: Dimitry Andric In-reply-to: <496F8D8A.1060508@andric.com> Date: Thu, 15 Jan 2009 11:35:21 -0800 References: <496D0364.2060505@psg.com> <47d0403c0901131335h46e7b151p3768de9a3e2c2027@mail.gmail.com> <085BEE07-BAE5-4A45-A14D-9587987FAA5C@mac.com> <496F44FA.1070004@andric.com> <48C1C477-B7BE-43B0-AC57-9DEB7BF9AA88@mac.com> <496F7347.4060007@andric.com> <496F8D8A.1060508@andric.com> X-Mailer: Apple Mail (2.930.3) Cc: Randy Bush , Luiz Otavio O Souza , George Neville-Neil , Ben Kaduk , current@freebsd.org Subject: Re: GEOM and moving to CURRENT from 7.1 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: Thu, 15 Jan 2009 19:35:37 -0000 On Jan 15, 2009, at 11:24 AM, Dimitry Andric wrote: > On 2009-01-15 19:05, Marcel Moolenaar wrote: >>> Hmm, strangely enough I have multiple systems which really do use >>> ad0s1 >>> while installed DD using sysinstall, and have been using that >>> since years... >> This is a problem with sysinstall. It looks like DD is broken. >> MBR partitions are always created. > > Indeed, and the MBR itself is filled with /boot/boot1, plus a > partition > table. It is possible this was done to appease some PC BIOSes, > because > some of those refuse to boot, if there is no "valid" MBR with an > active > partition... You need a boot sector for the BIOS to jump into, but it doesn't have to be a MBR with slices. That's why a DD has something that looks an awful lot like a MBR in the first sector. It could very well be boot sector of an FAT* file system. > >> GEOM_PART correctly uses the >> BSD disklabel that's in the 2nd sector, but GEOM_MBR claims the >> MBR being unaware that the disk is DD. > > But how can this be, if I don't have GEOM_MBR in my kernel config? > (I'm > using GENERIC, in fact.) sys/i386/config DEFAULTS is included implicitly. It used to have GEOM_BSD and GEOM_MBR. >> libdisk is broken in that it should >> not create MBR slices for DD configurations to begin with... > > As stated above, this might be on purpose; enough braindead BIOSes out > there... :) Creating ambiguous, conflicting and/or overlapping partition information to work around broken BIOSes to support DD, is not a solution *if* it was on purpose. You want it to fail so that the user partitions the disk in the normal way. Put differently: if there are enough braindead BIOSes out there that won't support DD, then DD should be de-supported by FreeBSD. -- Marcel Moolenaar xcllnt@mac.com