From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (mx1.redhat.com [172.16.48.31]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id l1HCurrZ007154 for ; Sat, 17 Feb 2007 07:56:53 -0500 Received: from percy.comedia.it (percy.comedia.it [212.97.59.71]) by mx1.redhat.com (8.13.1/8.13.1) with ESMTP id l1HCuosd001192 for ; Sat, 17 Feb 2007 07:56:51 -0500 Date: Sat, 17 Feb 2007 13:56:44 +0100 From: Luca Berra Subject: Re: [linux-lvm] vgdisplay - checksum error - what does it mean? Message-ID: <20070217125644.GC11919@percy.comedia.it> References: <45D448F5.3000301@wpkg.org> <45D47AF5.2040106@wpkg.org> <20070216074737.GA14119@percy.comedia.it> <45D57D16.8060902@wpkg.org> Mime-Version: 1.0 Content-Disposition: inline In-Reply-To: <45D57D16.8060902@wpkg.org> Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" Content-Transfer-Encoding: 7bit To: linux-lvm@redhat.com On Fri, Feb 16, 2007 at 10:44:54AM +0100, Tomasz Chmielewski wrote: >>>So this basically means, that LVM was set up on /dev/sda2 some time >>>ago, but it was never removed from there - instead, RAID-10 was set up >>>on that partition? >> >>I don't think so. if sda2 is part of a raid10 md array probably the >>beginning sector of the md device maps to the beginning sector of the >>real device, hence lvm will find an lvm signature on /dev/sda2. > >Is there a way to check if it's really the case? dd? >There's something wrong with /dev/sda2 - lvmdiskscan claims it's a >371.58 GB LVM physical volume, while /dev/md2 is the physical volume I use. > > /dev/sda2 [ 371.58 GB] LVM physical volume > /dev/md2 [ 743.16 GB] LVM physical volume > > >>>Should I do something to fix the things? What? >>yes, re-enable md_component_detection in lvm.conf, why did you disable >>that? > >Certainly I didn't touch anything in /etc/lvm/*. >If I look into /etc/lvm/lvm.conf, it says: > >devices { >(...) > # By default, LVM2 will ignore devices used as components of > # software RAID (md) devices by looking for md superblocks. > # 1 enables; 0 disables. > md_component_detection = 1 >} > >It's enabled. > >So the problem is somewhere else. Where? with md_component_detection enabled lvm should ignore /dev/sda2. can you send the output of lvmdiskscan -vvv? >BTW, the machine is running Debian etch (ARM port). mmm i don't have an arm maybe this is the issue why lvm does not understand that sda2 is a md component?!? >"smartctl" says all four disks are fine (they are quite new, too), so >it's definitely not a hardware problem. sure it is not an hw problem do not worry. >I guess one way to fix it would be mark all partitions faulty on >/dev/sda, and then, to recreate the RAIDs. >But I'm curious to know how could I handle such a situation if I didn't >have RAID. what would it fix? you have no problem except lvm2 believing sda2 is an lvm volume which is not. -- Luca Berra -- bluca@comedia.it Communication Media & Services S.r.l. /"\ \ / ASCII RIBBON CAMPAIGN X AGAINST HTML MAIL / \