Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763155AbXHDC6F (ORCPT ); Fri, 3 Aug 2007 22:58:05 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761531AbXHDC5x (ORCPT ); Fri, 3 Aug 2007 22:57:53 -0400 Received: from smtp.knology.net ([24.214.63.101]:48675 "EHLO smtp.knology.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756245AbXHDC5v (ORCPT ); Fri, 3 Aug 2007 22:57:51 -0400 Subject: Re: Distributed storage. From: Dave Dillow To: Manu Abraham Cc: Evgeniy Polyakov , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org In-Reply-To: <1a297b360708022204u4fc7603pb6baebe2bdf28618@mail.gmail.com> References: <20070731171347.GA14267@2ka.mipt.ru> <1a297b360708022204u4fc7603pb6baebe2bdf28618@mail.gmail.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Fri, 03 Aug 2007 22:51:08 -0400 Message-Id: <1186195868.16431.5.camel@obelisk.thedillows.org> Mime-Version: 1.0 X-Mailer: Evolution 2.8.3 (2.8.3-2.fc6) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1653 Lines: 33 On Fri, 2007-08-03 at 09:04 +0400, Manu Abraham wrote: > On 7/31/07, Evgeniy Polyakov wrote: > > > TODO list currently includes following main items: > > * redundancy algorithm (drop me a request of your own, but it is highly > > unlikley that Reed-Solomon based will ever be used - it is too slow > > for distributed RAID, I consider WEAVER codes) > > > LDPC codes[1][2] have been replacing Turbo code[3] with regards to > communication links and we have been seeing that transition. (maybe > helpful, came to mind seeing the mention of Turbo code) Don't know how > weaver compares to LDPC, though found some comparisons [4][5] But > looking at fault tolerance figures, i guess Weaver is much better. > > [1] http://www.ldpc-codes.com/ > [2] http://portal.acm.org/citation.cfm?id=1240497 > [3] http://en.wikipedia.org/wiki/Turbo_code > [4] http://domino.research.ibm.com/library/cyberdig.nsf/papers/BD559022A190D41C85257212006CEC11/$File/rj10391.pdf > [5] http://hplabs.hp.com/personal/Jay_Wylie/publications/wylie_dsn2007.pdf Searching Google for Dr. Plank's work at the University of TN turns up some analysis of using LDPC codes in storage systems. http://www.google.com/search?hl=en&q=plank+ldpc&btnG=Google+Search Patents are an issue to watch out for around the use of Tornado/Raptor codes. I've not researched it, but I believe there be dragons there. - 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/