Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422673AbWASWR5 (ORCPT ); Thu, 19 Jan 2006 17:17:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1422670AbWASWR5 (ORCPT ); Thu, 19 Jan 2006 17:17:57 -0500 Received: from host233.omnispring.com ([69.44.168.233]:60168 "EHLO iradimed.com") by vger.kernel.org with ESMTP id S1422668AbWASWR4 (ORCPT ); Thu, 19 Jan 2006 17:17:56 -0500 Message-ID: <43D00FFA.1040401@cfl.rr.com> Date: Thu, 19 Jan 2006 17:17:30 -0500 From: Phillip Susi User-Agent: Thunderbird 1.5 (Windows/20051201) MIME-Version: 1.0 To: Neil Brown CC: Jan Engelhardt , "Lincoln Dale (ltd)" , Michael Tokarev , linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, "Steinar H. Gunderson" Subject: Re: [PATCH 000 of 5] md: Introduction References: <26A66BC731DAB741837AF6B2E29C1017D47EA0@xmb-hkg-413.apac.cisco.com> <17358.52476.290687.858954@cse.unsw.edu.au> In-Reply-To: <17358.52476.290687.858954@cse.unsw.edu.au> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 19 Jan 2006 22:18:47.0925 (UTC) FILETIME=[51856250:01C61D46] X-TM-AS-Product-Ver: SMEX-7.2.0.1122-3.51.1032-14216.000 X-TM-AS-Result: No--11.200000-5.000000-2 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1391 Lines: 35 I'm currently of the opinion that dm needs a raid5 and raid6 module added, then the user land lvm tools fixed to use them, and then you could use dm instead of md. The benefit being that dm pushes things like volume autodetection and management out of the kernel to user space where it belongs. But that's just my opinion... I'm using dm at home because I have a sata hardware fakeraid raid-0 between two WD 10,000 rpm raptors, and the dmraid utility correctly recognizes that and configures device mapper to use it. Neil Brown wrote: > Which bits? > Why? > > My current opinion is that you should: > > Use md for raid1, raid5, raid6 - anything with redundancy. > Use dm for multipath, crypto, linear, LVM, snapshot > Use either for raid0 (I don't think dm has particular advantages > for md or md over dm). > > These can be mixed together quite effectively: > You can have dm/lvm over md/raid1 over dm/multipath > with no problems. > > If there is functionality missing from any of these recommended > components, then make a noise about it, preferably but not necessarily > with code, and it will quite possibly be fixed. - 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/