From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-in-06.arcor-online.net ([151.189.21.46]:51335 "EHLO mail-in-06.arcor-online.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752953Ab3KUT4S (ORCPT ); Thu, 21 Nov 2013 14:56:18 -0500 Date: Thu, 21 Nov 2013 20:56:03 +0100 From: Piergiorgio Sartor To: Stan Hoeppner Cc: James Plank , Ric Wheeler , Andrea Mazzoleni , "H. Peter Anvin" , linux-raid@vger.kernel.org, linux-btrfs@vger.kernel.org, David Brown , David Smith Subject: Re: Triple parity and beyond Message-ID: <20131121195603.GA1916@lazy.lzy> References: <528A90B7.5010905@zytor.com> <528AA1EB.3010909@zytor.com> <528BCA2D.5010500@redhat.com> <73BEB41F-0FAC-4108-BEA9-DB6D921F6F55@cs.utk.edu> <528D61C5.70902@hardwarefreak.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <528D61C5.70902@hardwarefreak.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Wed, Nov 20, 2013 at 07:28:37PM -0600, Stan Hoeppner wrote: [...] > It's always perilous to follow a Ph.D., so I guess I'm feeling suicidal > today. ;) > > I'm not attempting to marginalize Andrea's work here, but I can't help > but ponder what the real value of triple parity RAID is, or quad, or > beyond. Some time ago parity RAID's primary mission ceased to be Hi Stan, my opinio is that you have to think in terms of storage devices which are not always available. Those are not simply directly connected HDDs, it could be more exotic. The example I consider is a p2p network storage, where the nodes are very little reliable. I guess that could be more. bye, -- piergiorgio