From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264299AbTLBDYQ (ORCPT ); Mon, 1 Dec 2003 22:24:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264300AbTLBDYQ (ORCPT ); Mon, 1 Dec 2003 22:24:16 -0500 Received: from bay7-f71.bay7.hotmail.com ([64.4.11.71]:39690 "EHLO hotmail.com") by vger.kernel.org with ESMTP id S264299AbTLBDYN (ORCPT ); Mon, 1 Dec 2003 22:24:13 -0500 X-Originating-IP: [209.98.246.157] X-Originating-Email: [joeblow341@hotmail.com] From: "Joe Blow" To: jgarzik@pobox.com Cc: linux-kernel@vger.kernel.org Subject: Re: Promise 20378 + 2.6.0-test10 + libata patch 1 Date: Tue, 02 Dec 2003 03:24:11 +0000 Mime-Version: 1.0 Content-Type: text/plain; format=flowed Message-ID: X-OriginalArrivalTime: 02 Dec 2003 03:24:11.0719 (UTC) FILETIME=[C1257570:01C3B883] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >No plans. Curiious: How come when I disable RAID support in the BIOS and just have it act just like a dumb IDE controller, why aren't the drives aren't recognized that way? The BIOS claims it is plugging them in as plain IDE drives, or is something still different about this controller, even in that mode? >Using standard kernel drivers, Promise RAID _is_ md. I understand what md is, but I don't understand how Promise RAID is md. If I set the controller to RAID in the BIOS, and I configure a RAID 1 mirror, for example, how is that md? In this mode, isn't one copy of the data being sent to the controller and the controller "intelligence" figures out that one copy of the data goes to each drive? Where is if it were providing two drives to the OS, the md driver would have to send two copies of the data across the bus, one to each drive? Perhaps this is a dumb question, but why are these RAID controller companies seemingly making this so difficult? To me it seems like the most logical way to design these controllers would be to make them look like standard IDE controllers to the system and hide the RAID complexities inside the controller intelligence. The most expensive part of these controllers for the manufacturers has to be in providing drivers and support for all the different, primarily MS, OSes. I must be missing something. _________________________________________________________________ Gift-shop online from the comfort of home at MSN Shopping! No crowds, free parking. http://shopping.msn.com