From owner-freebsd-stable@FreeBSD.ORG Tue Aug 21 06:00:04 2007 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id F09DF16A418 for ; Tue, 21 Aug 2007 06:00:04 +0000 (UTC) (envelope-from matrix@itlegion.ru) Received: from corpmail.itlegion.ru (corpmail.itlegion.ru [84.21.226.211]) by mx1.freebsd.org (Postfix) with SMTP id 2E11B13C46E for ; Tue, 21 Aug 2007 06:00:03 +0000 (UTC) (envelope-from matrix@itlegion.ru) Received: (qmail 98128 invoked from network); 21 Aug 2007 10:00:02 +0400 Received: from unknown (HELO Artem) (192.168.0.12) by 84.21.226.211 with SMTP; 21 Aug 2007 10:00:02 +0400 X-AntiVirus: Checked by Dr.Web [version: 4.33, engine: 4.33.5.10110, virus records: 238958, updated: 20.08.2007] Message-ID: <03bc01c7e3b8$7f9a3a50$0c00a8c0@Artem> From: "Artem Kuchin" To: "Martin Nilsson" References: <028f01c7e37a$d8f441b0$0c00a8c0@Artem> <46CA7681.3070909@gneto.com> Date: Tue, 21 Aug 2007 09:59:51 +0400 Organization: IT Legion MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 Cc: freebsd-stable@freebsd.org Subject: Re: A little story of failed raid5 (3ware 8000 series) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 21 Aug 2007 06:00:05 -0000 Martin Nilsson wrote: > Artem Kuchin wrote: >> But i don't understand how and why it happened. ONly 6 hours ago (a >> night before) >> all those files were backed up fine w/o any read error. And now, >> right after replacing >> the driver and starting rebuild it said that there are bad sectors >> all over those file. >> How come? > > That is what patrol read is intended to detect before it is a problem. > In a RAID5 array the checksums are only used when reconstructing data, > if you have a bad block in a checksum sector it will not be detected > until a drive have failed and you try to rebuild the array, > unfortunately at that time it is too late... > > Beware that OS software solutions like diskcheckd will not find this > as it only reads the data, not the checksums, it must be done on the > controller. That exactly was i was talking about. I don't acess to individual disks behind raid unit, so, i cannot doit. I don't know it controller VERIFY command does it right. If it doesm then i shoudl put it into a cron job and do it on weekly basis. Also, it would halpfull it i could get access to number of left reserved sector for remapping. Any idea about these two for 3ware controllers? Also, someone should mention, that while using raid MUST do verifies often. -- Artem