From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932342AbWFMWb1 (ORCPT ); Tue, 13 Jun 2006 18:31:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964783AbWFMWb0 (ORCPT ); Tue, 13 Jun 2006 18:31:26 -0400 Received: from outpipe-village-512-1.bc.nu ([81.2.110.250]:56491 "EHLO lxorguk.ukuu.org.uk") by vger.kernel.org with ESMTP id S932342AbWFMWb0 (ORCPT ); Tue, 13 Jun 2006 18:31:26 -0400 Subject: Re: How does RAID work with IT8212 RAID PCI card? From: Alan Cox To: Lennart Sorensen Cc: Christian H?rtwig , linux-kernel@vger.kernel.org In-Reply-To: <20060613160138.GC560@csclub.uwaterloo.ca> References: <200606131758.45704.christian.haertwig@gmx.de> <20060613160138.GC560@csclub.uwaterloo.ca> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Tue, 13 Jun 2006 23:47:27 +0100 Message-Id: <1150238847.2232.1.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.6.2 (2.6.2-1.fc5.5) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Ar Maw, 2006-06-13 am 12:01 -0400, ysgrifennodd Lennart Sorensen: > Congratulations. You have a fake raid card by the sound of it. A > hardware raid card would have only shown one drive, while a fake raid > card expects the driver to work with the bios to find out the setup (and > handle booting), and then the driver does all the raid work in software. The IT8212 is not a fake raid card - it depends on the firmware whether you see a drive per raid volume (hardware raid mode) or not (ATAPI capable firmware). We've found the raid firmware seems quite temperamental and there is little performance gain from raid 1 in hardware over software so using md or device mapper is recommended for that reason.