Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754409AbYGGJ6T (ORCPT ); Mon, 7 Jul 2008 05:58:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751819AbYGGJ6H (ORCPT ); Mon, 7 Jul 2008 05:58:07 -0400 Received: from yw-out-2324.google.com ([74.125.46.30]:63685 "EHLO yw-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751319AbYGGJ6G (ORCPT ); Mon, 7 Jul 2008 05:58:06 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mail-followup-to:references :mime-version:content-type:content-disposition:in-reply-to :user-agent; b=mx6q9osxBSkR/jOKbsJUWzHCVPta4XSbNE9x5UoFovu6FkSiTmQLzNjjuqIdrc2Cwu kF/5e+iSVPnuMnE05I1o/TqevxMqO7UtMeU3Y4CtkyNCI+PiwpkweehxTVevPROZjRJi VM/lHFPq1ysfuDBIcO7bXxeoP8cPZSfUBnMpo= Date: Mon, 7 Jul 2008 05:57:48 -0400 From: Joseph Fannin To: Timothy Normand Miller Cc: Arjan van de Ven , linux-kernel@vger.kernel.org Subject: Re: HELP: Getting unexpected fakeraid behavior. Fix? Message-ID: <20080707095747.GC1631@nineveh.local> Mail-Followup-To: Timothy Normand Miller , Arjan van de Ven , linux-kernel@vger.kernel.org References: <9871ee5f0807061307ncc55104y477c57be3e91b75f@mail.gmail.com> <20080706131937.13065312@infradead.org> <9871ee5f0807061424o535c6d7eg3071da6e31e0b58e@mail.gmail.com> <9871ee5f0807061822l2871765bhd92aa177c0d5d55b@mail.gmail.com> <9871ee5f0807061826r101a1aboe266a3432af650a2@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9871ee5f0807061826r101a1aboe266a3432af650a2@mail.gmail.com> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1397 Lines: 31 On Sun, Jul 06, 2008 at 09:26:35PM -0400, Timothy Normand Miller wrote: > I was poking around some more, and I found drivers/md/raid1.c. This > has sophisticated load balancing for reads. Why isn't this code being > used for dm_raid1? I'm a bit confused as to why this redundant code > should be there if dmraid and mdraid are functionally the same. I don't think dmraid and mdraid *are* functionally the same. dmraid was written as more or less a compatibilty hack, so people using fakeRAID with its Windows-only software drivers could still dual-boot. That could have changed somewhat while I wasn't looking, but it doesn't sound like it has changed much. mdraid is still the only "real" Linux softRAID implementation... though LVM also does some very RAID-like things. It would be good if dmraid was better optimized, or more complete -- possibly by reusing some of md -- but no one has done the work. Anyway, the consensus for a long time seems to be that, unless you need to dual-boot with a Windows system using fakeRAID drivers, you should just put the drive controller in AHCI mode and use mdraid. -- Joseph Fannin jfannin@gmail.com -- 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/