From owner-freebsd-chat@FreeBSD.ORG Sat Dec 20 19:24:54 2008 Return-Path: Delivered-To: freebsd-chat@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2F8961065673 for ; Sat, 20 Dec 2008 19:24:54 +0000 (UTC) (envelope-from mitchell@wyatt672earp.force9.co.uk) Received: from pih-relay06.plus.net (pih-relay06.plus.net [212.159.14.19]) by mx1.freebsd.org (Postfix) with ESMTP id E7A268FC17 for ; Sat, 20 Dec 2008 19:24:53 +0000 (UTC) (envelope-from mitchell@wyatt672earp.force9.co.uk) Received: from [81.174.212.186] (helo=81-174-212-186.pth-as5.dial.plus.net) by pih-relay06.plus.net with esmtp (Exim) id 1LE71y-0001cx-1f; Sat, 20 Dec 2008 18:58:30 +0000 From: Frank Mitchell To: staffslug@staffslug.org.uk, sc@mailman.lug.org.uk, freebsd-chat@freebsd.org, ukfreebsd@uk.freebsd.org Date: Sat, 20 Dec 2008 18:49:45 +0000 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) MIME-Version: 1.0 Content-Disposition: inline Message-Id: <200812201849.45914.mitchell@wyatt672earp.force9.co.uk> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Plusnet-Relay: dbbcb3c40ec5d82870617073eb3a534d Cc: Subject: File System Ext2 On DVD+RW X-BeenThere: freebsd-chat@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Non technical items related to the community List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 20 Dec 2008 19:24:54 -0000 Hi: Recently I noticed Sun Solaris used CDs with a UFS File System. So I decided to try UFS and Ext2 on Optical Disks. It should work on CD-RW, but I had spare DVD+RW disks, so I decided to get more ambitious. Note that DVDs use 2048-byte Sectors like CDs, but they're handled in Error-Correcting Blocks of 16. You can't expect DVD-RW to work, because DVD-RW only writes complete ECC Blocks. But DVD+RW (like DVD-RAM) can update individual Sectors. FreeBSD UFS1 wouldn't work this way. The FreeBSD Handbook gives instructions for DVD-RAM, and obviously DVD-RAM has a different layout. But OpenSUSE Linux seems okay with Ext2 on DVD+RW. I copied a large Subtree and checked the result using diff -qr. Does anybody have thoughts about this idea? Like: Any disadvantages which haven't occurred to me? Obviously if you're recording Personal Information on Removable Media it might be preferable to use a format which isn't readable under Windows. Faictz Ce Que Vouldras: Frank Mitchell