Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 4 Jun 2002 22:51:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 4 Jun 2002 22:51:22 -0400 Received: from vladimir.pegasys.ws ([64.220.160.58]:24079 "HELO vladimir.pegasys.ws") by vger.kernel.org with SMTP id ; Tue, 4 Jun 2002 22:51:21 -0400 Date: Tue, 4 Jun 2002 19:51:13 -0700 From: jw schultz To: linux-kernel@vger.kernel.org Subject: Re: RAID-6 support in kernel? Message-ID: <20020604195113.G7742@pegasys.ws> Mail-Followup-To: jw schultz , linux-kernel@vger.kernel.org In-Reply-To:

<20020603113128.C13204@ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.3.12i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jun 03, 2002 at 11:31:28AM +0200, Vojtech Pavlik wrote: > On Mon, Jun 03, 2002 at 02:25:22AM -0700, Derek Vadala wrote: > > He was thinking "mirror", not "stripe". Mirror of 2 RAID-5 arrays (would > be probably called RAID-15 (when there is a RAID-10 for mirrored stripe > arrays)), can withstand any two disks failing anytime. Even more for > certain combinations. But it is terribly inefficient. All the authoritative literature says that RAID-10 is striped mirrors (survive ~1/n 2 disk failures.) RAID-0+1 is mirrored stripes (survive ~1/2 2 disk failures.) What he is describing would be RAID-5+1, mirrored RAID-5s. RAID-15 would be a RAID-5 of mirrors. Both of these could survive any 3 disk failures. -- ________________________________________________________________ J.W. Schultz Pegasystems Technologies email address: jw@pegasys.ws Remember Cernan and Schmitt - 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/