From owner-freebsd-questions@FreeBSD.ORG Wed Apr 23 20:01:17 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B78C11065679 for ; Wed, 23 Apr 2008 20:01:17 +0000 (UTC) (envelope-from andrewhw@ieee.org) Received: from post.queensu.ca (post.QueensU.CA [130.15.126.6]) by mx1.freebsd.org (Postfix) with ESMTP id 3DD618FC15 for ; Wed, 23 Apr 2008 20:01:17 +0000 (UTC) (envelope-from andrewhw@ieee.org) Received: from U48.N136.QueensU.CA (U48.N136.QueensU.CA [130.15.136.48]) by post.queensu.ca (8.13.1/8.13.1) with ESMTP id m3NK1Dh5011966 for ; Wed, 23 Apr 2008 16:01:13 -0400 (EDT) Date: Wed, 23 Apr 2008 17:01:12 -0300 (ADT) From: Andrew Hamilton-Wright Sender: andrew@qemg.org To: freebsd-questions@freebsd.org In-Reply-To: Message-ID: References: User-Agent: Alpine 1.10 (BSF 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Subject: Re: OpenBSD -> FreeBSD migration X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 23 Apr 2008 20:01:17 -0000 The results of my investigation so far are below: > Filesystem stuff: > - it appears that FreeBSD and OpenBSD use the same partition > table format. Is this true? If so, I can potentially avoid > rebuilding an entire disk if I am right that ... > - FreeBSD can mount and read OpenBSD's version of the 4.2 BSD > filesystem implementation Although I strongly suspect that the filesystem itself is probably the same, it is not possible to read an OpenBSD mounted partition, as far as I can tell. After booting using FreeBSD, fdisk correctly reports the information regarding the slice set up by OpenBSD (default 4, not 1, the FreeBSD default), however bsdlabel under FreeBSD cannot interpret any of the data found at the location reported in the table read by fdisk. I do find this somewhat surprising, as it is the same structures that are being recorded. Perhaps there is a magic number issue here that causes bsdlabel to believe that it can't interpret the data as the message returned is that there is no label present in the indicated slice. This makes the filesystem question moot, as without access to the BSD partition results there is no clue as to where to begin access of the filesystem. > - even if the above isn't true, it appears that the format used > by dump/restore is consistent. I have tried dumping/restoring > some small filesystems to test this, but if this is an unsupported > way to go, I would like to know now. This seems to work. I was successfully able to dump filesystems under OpenBSD and then restore them under FreeBSD, with general success (albeit a complaint that the dump header is out of date). Cheers, Andrew.