From owner-freebsd-hackers@FreeBSD.ORG Sat Jul 29 09:50:08 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DDA8116A4DE for ; Sat, 29 Jul 2006 09:50:08 +0000 (UTC) (envelope-from andreas@klemm.apsfilter.org) Received: from srv1.cosmo-project.de (srv1.cosmo-project.de [213.83.6.106]) by mx1.FreeBSD.org (Postfix) with ESMTP id ED54543D46 for ; Sat, 29 Jul 2006 09:50:07 +0000 (GMT) (envelope-from andreas@klemm.apsfilter.org) Received: from srv1.cosmo-project.de (localhost [IPv6:::1]) by srv1.cosmo-project.de (8.12.10/8.12.10) with ESMTP id k6T9o5nZ017777 (version=TLSv1/SSLv3 cipher=EDH-RSA-DES-CBC3-SHA bits=168 verify=NO) for ; Sat, 29 Jul 2006 11:50:06 +0200 (CEST) (envelope-from andreas@klemm.apsfilter.org) Received: (from uucp@localhost) by srv1.cosmo-project.de (8.12.10/8.12.10/Submit) with UUCP id k6T9o51L017776 for freebsd-hackers@freebsd.org; Sat, 29 Jul 2006 11:50:05 +0200 (CEST) (envelope-from andreas@klemm.apsfilter.org) Received: from titan.klemm.apsfilter.org (localhost.klemm.apsfilter.org [127.0.0.1]) by klemm.apsfilter.org (8.13.6/8.13.4) with ESMTP id k6T9liMs005939 for ; Sat, 29 Jul 2006 11:47:44 +0200 (CEST) (envelope-from andreas@titan.klemm.apsfilter.org) Received: (from andreas@localhost) by titan.klemm.apsfilter.org (8.13.6/8.13.4/Submit) id k6T9lhn4005938 for freebsd-hackers@freebsd.org; Sat, 29 Jul 2006 11:47:43 +0200 (CEST) (envelope-from andreas) Date: Sat, 29 Jul 2006 11:47:43 +0200 From: Andreas Klemm To: freebsd-hackers@freebsd.org Message-ID: <20060729094743.GA5840@titan.klemm.apsfilter.org> References: <20060727063936.GA1246@titan.klemm.apsfilter.org> <20060727122159.GB4217@britannica.bec.de> <20060727202528.GA14954@titan.klemm.apsfilter.org> <200607282236.k6SMaRlj089446@apollo.backplane.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200607282236.k6SMaRlj089446@apollo.backplane.com> X-Operating-System: FreeBSD 6.1-STABLE X-Disclaimer: A free society is one where it is safe to be unpopular User-Agent: Mutt/1.5.11 Subject: Re: disklabel differences FreeBSD, DragonFly 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: Sat, 29 Jul 2006 09:50:09 -0000 On Fri, Jul 28, 2006 at 03:36:27PM -0700, Matthew Dillon wrote: > :On Thu, Jul 27, 2006 at 02:21:59PM +0200, Joerg Sonnenberger wrote: > :> On Thu, Jul 27, 2006 at 08:39:37AM +0200, Andreas Klemm wrote: > : > :Hmm, for the sake of compatibility, wouldn't it have been an option, > :to add this extra bit to the end of the struct ? > : Andreas /// > > The thing to note here is that FreeBSD had to make room for the > UFS1+UFS2 boot code, so it moved the boot code back to the point > where it abuts the 8-partition-sized disklabel. > > So at least insofar as FreeBSD goes, the partition table cannot be > expanded to 16 partitions with UFS1+UFS2 boot code. I'm guessing > that it *could* be expanded to 16 partitions with UFS1 only or > UFS2 only boot code (assuming the boot code were relocated back > to where it was originally in FreeBSD-4/5 times, before UFS2 came > along). > > With regards to simply recognizing a DragonFly partition... yes, > that would be easy to do. Since FreeBSD is now devfs-based, the > bit we had to steal to support 16 partitions in /dev isn't an issue. Couldn't all BSDs restructure the disklabel in -current so that we would have the same base for the next major release ? Then its only a question of drivers to suppot UFS2 or not. But then compatibility would be there for some time ... Incompatible to UFS's like from Sun I think we are already, so we don't have to honour them. Remember a current thread in german BSD group where somebody complained about FreeBSD - mounting a Sun filesystem r/w - destroyed the filesystem. Luckily he could recover using fsck -b 32. Andreas /// -- Andreas Klemm - Powered by FreeBSD 6 Need a magic printfilter today ? -> http://www.apsfilter.org/