From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bernd Schubert Subject: Re: Reopen: 16 HDDs too much for RAID6? Date: Fri, 28 Mar 2008 11:14:40 +0100 Message-ID: <200803281114.41018.bs@q-leap.de> References: <20080306100128.8daad6bd.taeuber@bbaw.de> <20080307114555.6ce17158.taeuber@bbaw.de> <20080328102002.a8b836b6.taeuber@bbaw.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20080328102002.a8b836b6.taeuber@bbaw.de> Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: Lars =?utf-8?q?T=C3=A4uber?= Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hallo Lars, On Friday 28 March 2008 10:20:02 Lars T=C3=A4uber wrote: > Hallo! > > Lars T=C3=A4uber schrieb: > > I zeroed out all physical devices completely: > > # for DEV in /dev/sd[c-r]; do dd if=3D/dev/zero of=3D$DEV; done why not simply "mdadm --zero-superblock $DEV"? > > > > Now the problem is gone. I don't know what really caused the proble= m. > > Many thanks for your suggestions. > > The problem has occured again. > I'm not sure what the cause was, but the duplicated superblock is the= re > again. But the raid fell apart before. So I suspect this occurs only = after > the array was degraded. The discs are not defective so I tried to > reassemble the array with the original discs again: monosan:~ # mdadm= -A > /dev/md4 > mdadm: WARNING /dev/dm-9 and /dev/dm-8 appear to have very similar > superblocks. If they are really different, please --zero the superblo= ck on > one If they are the same or overlap, please remove one from the > DEVICE list in mdadm.conf. > > How can I extract the superblocks to check if they are really identic= ally? mdadm --examine /dev/dm-9 mdadm --examine /dev/dm-8 Do you have some kind of multipathing, which really could cause a ident= ical=20 superblocks on dm-9 and dm-8? Did you specify dm-9 and dm-8 in you=20 mdadm.conf / assemble script or the real human readable lvm / multipath= =20 names? Cheers, Bernd --=20 Bernd Schubert Q-Leap Networks GmbH -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html