Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759972AbXFQMEj (ORCPT ); Sun, 17 Jun 2007 08:04:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758864AbXFQME1 (ORCPT ); Sun, 17 Jun 2007 08:04:27 -0400 Received: from mx2.suse.de ([195.135.220.15]:45001 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758527AbXFQMEY (ORCPT ); Sun, 17 Jun 2007 08:04:24 -0400 To: Neil Brown Cc: Avi Kivity , david@lang.hm, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org Subject: Re: limits on raid References: <18034.479.256870.600360@notabene.brown> <18034.3676.477575.490448@notabene.brown> <467273AB.9010202@argo.co.il> <18035.3009.568832.785308@notabene.brown> From: Andi Kleen Date: 17 Jun 2007 15:00:24 +0200 In-Reply-To: <18035.3009.568832.785308@notabene.brown> Message-ID: User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.3 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 770 Lines: 15 Neil Brown writes: > > Having the filesystem duplicate data, store checksums, and be able to > find a different copy if the first one it chose was bad is very > sensible and cannot be done by just putting the filesystem on RAID. Apropos checksums: since RAID5 copies/xors anyways it would be nice to combine that with the file system. During the xor a simple checksum could be computed in parallel and stored in the file system. And the copy/checksum passes will hopefully at some point be combined. -Andi - 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/