From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mailgw-01.dd24.net ([193.46.215.41]:40235 "EHLO mailgw-01.dd24.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757630AbcK2OZS (ORCPT ); Tue, 29 Nov 2016 09:25:18 -0500 Message-ID: <1480429494.3155.7.camel@scientia.net> Subject: Re: [PATCH] btrfs: raid56: Use correct stolen pages to calculate P/Q From: Christoph Anton Mitterer To: Adam Borowski Cc: Zygo Blaxell , Goffredo Baroncelli , Qu Wenruo , linux-btrfs@vger.kernel.org Date: Tue, 29 Nov 2016 15:24:54 +0100 In-Reply-To: <20161129073526.GA2441@angband.pl> References: <20161121085016.7148-1-quwenruo@cn.fujitsu.com> <94606bda-dab0-e7c9-7fc6-1af9069b64fc@inwind.it> <20161125043119.GG8685@hungrycats.org> <1480304269.6254.6.camel@scientia.net> <2b15ae6f-51ce-45ff-47c0-699506de4e56@inwind.it> <20161128214829.GO8685@hungrycats.org> <1480384367.6747.46.camel@scientia.net> <20161129073526.GA2441@angband.pl> Content-Type: multipart/signed; micalg="sha-512"; protocol="application/x-pkcs7-signature"; boundary="=-ZkytUD1VBdXGE7OhGYUh" Mime-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org List-ID: --=-ZkytUD1VBdXGE7OhGYUh Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2016-11-29 at 08:35 +0100, Adam Borowski wrote: > I administer no real storage at this time, and got only 16 disks > (plus a few > disk-likes) to my name right now.=C2=A0=C2=A0Yet in a ~2 months span I've= seen > three > cases of silent data corruption I didn't meant to say we'd have no silent data corruption. OTOH, we cannot have had many of them, since the storage management software itself has another layer of checksumming. What I meant to say is that we likely never had such a scenario described by Zygo, where e.g. broken HDD controller memory would cause corruptions (and which would be then bad in case of auto-RAID-repair- on-read). Cause IMO such memory issues would rather soon be noticed. 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