From owner-freebsd-current@FreeBSD.ORG Thu Feb 19 07:06:01 2004 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 5508316A4CE for ; Thu, 19 Feb 2004 07:06:01 -0800 (PST) Received: from harmony.village.org (rover.bsdimp.com [204.144.255.66]) by mx1.FreeBSD.org (Postfix) with ESMTP id F1EE843D1D for ; Thu, 19 Feb 2004 07:06:00 -0800 (PST) (envelope-from imp@bsdimp.com) Received: from localhost (warner@rover2.village.org [10.0.0.1]) by harmony.village.org (8.12.10/8.12.9) with ESMTP id i1JF60nJ078171; Thu, 19 Feb 2004 08:06:00 -0700 (MST) (envelope-from imp@bsdimp.com) Date: Thu, 19 Feb 2004 08:05:50 -0700 (MST) Message-Id: <20040219.080550.79264640.imp@bsdimp.com> To: andy@siliconlandmark.com From: "M. Warner Losh" In-Reply-To: <20040219025604.D76134@alpha.siliconlandmark.com> References: <39796.1077013415@critter.freebsd.dk> <20040218.063204.74403147.imp@bsdimp.com> <20040219025604.D76134@alpha.siliconlandmark.com> X-Mailer: Mew version 3.3 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit cc: current@freebsd.org Subject: Re: Review/Test: Pseudo-device unit number management patch X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Feb 2004 15:06:01 -0000 In message: <20040219025604.D76134@alpha.siliconlandmark.com> Andre Guibert de Bruet writes: : The likes of ATA disks include serial numbers in words 10-19. These could : be used to positively identify a drive when its availability has come : into question. From what I recall, CF cards use an ATA-like command set. : Wouldn't it be possible to get the serial number and model from them for : positive identification? Not when I tried it a few years ago. The serial numbers were all 0 at the time (at least on the brands of parts I was messing with). Things may have changed since then. And that's not a property of the controller, but the disk connected to the controller, which starts to get messy from a layering point of view. Besides, you'd have to keep a history around for a 'while' of what the unique key was, and that has other issues if you are inserting lots of different CF into a machine (say to create bootable CF for production). Warner