From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752036Ab0CSS0l (ORCPT ); Fri, 19 Mar 2010 14:26:41 -0400 Received: from mail-fx0-f213.google.com ([209.85.220.213]:50100 "EHLO mail-fx0-f213.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751013Ab0CSS0k convert rfc822-to-8bit (ORCPT ); Fri, 19 Mar 2010 14:26:40 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :content-type:content-transfer-encoding; b=SgibSgMlmGrqjvOkuEdof7xoU2OJUBUCpNpJe6WG2TbbZPJ8CscgHCX9JhTgTrqmmf IoX1P+zc4IDXDU2itis/iO4LYlZYgD7LNsQfIhPlAurkDawEmBldunP0WzQpiUNdk1xH Pc1UhU5eoQRvNrn9AyyRmkXJalOt/M719JHR4= MIME-Version: 1.0 In-Reply-To: <73e903671003191123h1b7e1196v336265842f1b29e5@mail.gmail.com> References: <4BA3C07A.8030204@gmx.net> <73e903671003191123h1b7e1196v336265842f1b29e5@mail.gmail.com> From: =?ISO-8859-1?Q?Kristleifur_Da=F0ason?= Date: Fri, 19 Mar 2010 18:26:18 +0000 Message-ID: <73e903671003191126l6c0bed69q69c32bf37922690d@mail.gmail.com> Subject: Re: BUG:write data to degrade raid5 To: linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 19, 2010 at 6:20 PM, Joachim Otahal wrote: > jin zhencheng schrieb: >> >> hi; >> >> i use kernel is 2.6.26.2 >> >> what i do as follow: >> >> 1, I create a raid5: >> mdadm -C /dev/md5 -l 5 -n 4 /dev/sda /dev/sdb /dev/sdc  /dev/sdd >> --metadata=1.0 --assume-clean >> >> 2, dd if=/dev/zero of=/dev/md5 bs=1M& >> >> write data to this raid5 >> >> 3, mdadm --manage /dev/md5 -f /dev/sda >> >> 4 mdadm --manage  /dev/md5 -f /dev/sdb >> >> if i faild 2 disks ,then the OS kernel display OOP error and kernel down >> >> do somebody know why ? >> >> Is MD/RAID5 bug ? >> > > RAID5 can only tolerate ONE drive to fail of ALL members. If you want to be > able to fail two drives you will have to use RAID6 or RAID5 with one > hot-spare (and give it time to rebuild before failing the second drive). > PLEASE read the documentation on raid levels, like on wikipedia. > That is true, but should we get a kernel oops and crash if two RAID5 drives are failed? (THAT part looks like a bug!) Jin, can you try a newer kernel, and a newer mdadm? -- Kristleifur