Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750908AbWCGQ53 (ORCPT ); Tue, 7 Mar 2006 11:57:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751142AbWCGQ53 (ORCPT ); Tue, 7 Mar 2006 11:57:29 -0500 Received: from prgy-npn2.prodigy.com ([207.115.54.38]:48728 "EHLO oddball.prodigy.com") by vger.kernel.org with ESMTP id S1750908AbWCGQ52 (ORCPT ); Tue, 7 Mar 2006 11:57:28 -0500 Message-ID: <4404CF1E.2010309@tmr.com> Date: Tue, 28 Feb 2006 17:30:54 -0500 From: Bill Davidsen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.1) Gecko/20060130 SeaMonkey/1.0 MIME-Version: 1.0 To: Jan Engelhardt CC: Sam Vilain , Luke-Jr , Jesper Juhl , Bernhard Rosenkraenzer , linux-kernel@vger.kernel.org Subject: Re: [slightly OT] dvdrecord 0.3.1 -- and yes, dev=/dev/cdrom works ;) References: <200602250042.51677.bero@arklinux.org> <200602261330.15709.luke@dashjr.org> <9a8748490602260529h3a2890bhce4112feefb7cb1f@mail.gmail.com> <200602261339.13821.luke@dashjr.org> <440240F8.3010207@vilain.net <44049D5A.1010806@cfl.rr.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1980 Lines: 38 Jan Engelhardt wrote: >>> Yes. A 650 MB *CD*-RW (DVD-RW too?) formatted in packet mode only has like >>> 500-something megabytes to allow for the sort of seeks required. >>> On DVD+RW, you get the full 4.3 GB (4.7 gB) AFAICS. >> DVD-RAM physically is formatted like a hard disk. It is broken up into zones >> that hold different numbers of sectors which are individually and randomly >> read/writable. CD/DVD+-RW media is organized as a single long groove that >> consists of an unbroken series of large blocks composed of small blocks with >> user and control data interleaved and error corrected. It is for this reason >> that historically it could only be recorded from start to finish in one pass. >> >> There are two modern techniques to allow pseudo random write access for all >> forms of CD/DVD +/- RW media. These are packet mode, and mount rainier mode. >> MRW mode formats the disk into 32 KB blocks made up of 2048 byte sectors which >> are individually writable as far as the OS knows, because an MRW compliant >> drive is required to internally handle any required read/modify/write cycles to >> update the 32 KB blocks. MRW mode also reserves some of the disk for sector >> sparing which the drive firmware also handles. MRW mode is typically used on >> dvd+rw media. IIRC, this format typically "wastes" about 10% of the capacity of >> the medium. >> > I doubt that. 10% of a 4.3 GB disk are, well, roughly 430 MB, which would > make df show 3.9 GB as mountpoint size, not 4.3 GB. [MB and GB are powers > of 1024 here.] > Was that DVD recorded MtR or packet? -- -bill davidsen (davidsen@tmr.com) "The secret to procrastination is to put things off until the last possible moment - but no longer" -me - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/