From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: On the subject of RAID-6 corruption recovery Date: Fri, 28 Dec 2007 09:38:16 -0500 Message-ID: <47750A58.1010702@tmr.com> References: <4774663C.5090609@zytor.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4774663C.5090609@zytor.com> Sender: linux-raid-owner@vger.kernel.org To: "H. Peter Anvin" Cc: Linux RAID Mailing List List-Id: linux-raid.ids H. Peter Anvin wrote: > I got a private email a while ago from Thiemo Nagel claiming that some > of the conclusions in my RAID-6 paper was incorrect. This was > combined with a "proof" which was plain wrong, and could easily be > disproven using basic enthropy accounting (i.e. how much information > is around to play with.) > > However, it did cause me to clarify the text portion a little bit. In > particular, *in practice* in may be possible to *probabilistically* > detect multidisk corruption. Probabilistic detection means that the > detection is not guaranteed, but it can be taken advantage of > opportunistically. If this means that there can be no false positives for multidisk corruption but may be false negatives, fine. If it means something else, please restate one more time. -- Bill Davidsen "Woe unto the statesman who makes war without a reason that will still be valid when the war is over..." Otto von Bismark