Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1945911AbWBCTWp (ORCPT ); Fri, 3 Feb 2006 14:22:45 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1945910AbWBCTWp (ORCPT ); Fri, 3 Feb 2006 14:22:45 -0500 Received: from mail.gmx.net ([213.165.64.21]:20680 "HELO mail.gmx.net") by vger.kernel.org with SMTP id S1945911AbWBCTWo convert rfc822-to-8bit (ORCPT ); Fri, 3 Feb 2006 14:22:44 -0500 X-Authenticated: #428038 Date: Fri, 3 Feb 2006 20:22:39 +0100 From: Matthias Andree To: Jan Engelhardt Cc: linux-kernel@vger.kernel.org Subject: Re: CD writing in future Linux (stirring up a hornets' nest) Message-ID: <20060203192239.GB18533@merlin.emma.line.org> Mail-Followup-To: Jan Engelhardt , linux-kernel@vger.kernel.org References: <43DDFBFF.nail16Z3N3C0M@burner> <1138710764.17338.47.camel@juerg-t40p.bitron.ch> <43DF6812.nail3B44TLQOP@burner> <20060202062840.GI5501@mail> <43E1EA35.nail4R02QCGIW@burner> <20060202161853.GB8833@voodoo> <43E374CF.nail5CAMKAKEV@burner> <43E38084.9040200@cfl.rr.com> <43E38B51.nail5CAZ1GYRE@burner> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: X-PGP-Key: http://home.pages.de/~mandree/keys/GPGKEY.asc User-Agent: Mutt/1.5.11 X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1264 Lines: 31 Jan Engelhardt schrieb am 2006-02-03: > > > >> You CAN'T have multiple cdrecord processes burning the same disc at the > >> same time; the very idea makes no sense. The O_EXCL just prevents you > >> from trying such foolishness and creating a coaster. > > > >It does not prevent you from creatig a coaster in case you connect e.g. > >two ATAPI writers to the same ATA cable. > > > Apart from transfer speed issues and potential buffer underruns coming > along with that, is there anything technically impossible with writing to > two ATAPI drives at the same time? Bus locking while waiting for command completion. If you start a long-lasting operation on one device, the other device on the same cable is blocked so you cannot feed the other. Same holds for SCSI if one of the devices involved doesn't disconnect from the bus for that long-lasting command. Try for instance "eject /dev/hdc" while writing to /dev/hdd, or same stuff with sr0 and sr1. Been there, done that, got a coaster. -- Matthias Andree - 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/