From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: Why do I need 4 disks for a raid6? Date: Wed, 01 Apr 2009 09:09:57 -0700 Message-ID: <49D391D5.1050509@zytor.com> References: <87ljr4hsk9.fsf@frosties.localdomain> <18882.54987.332211.49180@notabene.brown> <20090323202043.GA3841@compegg.wr.niftyegg.com> <87ljquemy3.fsf@frosties.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87ljquemy3.fsf@frosties.localdomain> Sender: linux-raid-owner@vger.kernel.org To: Goswin von Brederlow Cc: Nifty Fedora Mitch , linux-raid@vger.kernel.org List-Id: linux-raid.ids Goswin von Brederlow wrote: > > Actually the definition I read was that raid6 is like raid5 but > allowing for 2 or more disks to fail without loss. So a 15 disks raid > with 10 data blocks and 5 parity blocks per stripe would also be raid6. > 2 or more *arbitrary* disks. You can't, say, have two RAID-5s and call the combination a RAID-6, because they're not all there. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.