From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joe Landman Subject: Re: Triple-parity raid6 Date: Sat, 11 Jun 2011 13:14:38 -0400 Message-ID: <4DF3A27E.8080806@gmail.com> References: <20110609114954.243e9e22@notabene.brown> <20110609220438.26336b27@notabene.brown> <87aadq5q1l.fsf@gmail.com> <4DF20C18.3030604@christoph-d.de> <20110611101312.GA3528@lazy.lzy> <20110611131801.GA2764@lazy.lzy> <4DF38424.1010500@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: David Brown Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids A quick note of caution (and someone from Netapp, feel free to speak up). Netapp has a patent on triple parity raid (c.f. http://www.freepatentsonline.com/7640484.html). A quick look over this, suggests that the major innovation is the layout and computation which they simplified in a particular manner. That is, I don't think their patent covers triple parity RAID in general, but does cover their implementation, and the diagonal parity with anti-diagonal parity (effectively counter propagating or orthogonalized parity). I am not sure what this means from a coding sense, other than not to use their techniques without a license to do so. If Netapp wants to grant such a license, this would be good, but I suspect that it wouldn't be quite as simple as this. Just a note so that we don't encounter problems. I think its very possible to avoid their IP, as it would somewhat hard to claim ownership of the Galois Field math behind RAID calculations. They can (and do) claim a particular implementation and algorithm. [also not trying to open the patent on code wars here, just pointing out the current situation ] -- Joseph Landman, Ph.D Founder and CEO Scalable Informatics, Inc. email: landman@scalableinformatics.com web : http://scalableinformatics.com http://scalableinformatics.com/sicluster phone: +1 734 786 8423 x121 fax : +1 866 888 3112 cell : +1 734 612 4615