From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268774AbUHLVAo (ORCPT ); Thu, 12 Aug 2004 17:00:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268785AbUHLVAn (ORCPT ); Thu, 12 Aug 2004 17:00:43 -0400 Received: from prgy-npn1.prodigy.com ([207.115.54.37]:32131 "EHLO oddball.prodigy.com") by vger.kernel.org with ESMTP id S268774AbUHLVAU (ORCPT ); Thu, 12 Aug 2004 17:00:20 -0400 Message-ID: <411BDB25.8070503@tmr.com> Date: Thu, 12 Aug 2004 17:03:33 -0400 From: Bill Davidsen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.2) Gecko/20040803 X-Accept-Language: en-us, en MIME-Version: 1.0 To: V13 CC: Martin Mares , Joerg Schilling , axboe@suse.de, James.Bottomley@steeleye.com, linux-kernel@vger.kernel.org Subject: Re: PATCH: cdrecord: avoiding scsi device numbering for ide devices References: <20040806231529.GA9997@ucw.cz><20040806231529.GA9997@ucw.cz> <200408071331.38793.v13@priest.com> In-Reply-To: <200408071331.38793.v13@priest.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org V13 wrote: > On Saturday 07 August 2004 02:15, Martin Mares wrote: > >>Hello! >> >> >>>Let me lead you to the right place to look for: >>> >>> The CAM interface (which is from the SCSI standards group) >>> usually is implemeted in a way that applications open /dev/cam and >>> later supply bus, target and lun in order to get connected >>> to any device on the system that talks SCSI. >>> >>>Let me repeat: If you believe that this is a bad idea, give very good >>>reasons. >> >>There is one: hotplug. The physical topology of buses where all the >>SCSI-like devices (being it ATAPI devices, iSCSI, USB disks or other such >>beasts) are connected is too complex, so every attempt to map them to the >>(bus, target, lun) triplets in any sane way is destined to fail. > > > Just to add on this, how is someone supposed to distinguish between two > identical USB recorders using the scanbus/X:Y:Z method? I suppose he'll have > to try writting to both drives each time he replugs them instead of > having /dev/cdr-red /dev/cdr-blue or something similar using hotplug/udev. cat /proc/scsi/usb-storage/* There is a utility (name escapes me) which allows binding of a NIC to a name by MAC address, it would be nice to be able to bind by serial number for IDE/SCSI/USB devices. However, until you do that, a simple script to create a few symlinks after discovery will solve your problem. Doesn't bug me enough to bother, but that's how. -- -bill davidsen (davidsen@tmr.com) "The secret to procrastination is to put things off until the last possible moment - but no longer" -me