From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Thomas J. Baker" Subject: Re: Any hope for a 27 disk RAID6+1HS array with four disks reporting "No md superblock detected"? Date: Wed, 04 Feb 2009 16:17:58 -0500 Message-ID: <1233782278.696.6.camel@localhost.localdomain> References: <1233775657.10151.5.camel@localhost.localdomain> <4989FF7B.6030503@scalableinformatics.com> <1233781437.696.2.camel@localhost.localdomain> Reply-To: tjb@unh.edu Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1233781437.696.2.camel@localhost.localdomain> Sender: linux-raid-owner@vger.kernel.org To: landman@scalableinformatics.com Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Wed, 2009-02-04 at 16:03 -0500, Thomas J. Baker wrote: > On Wed, 2009-02-04 at 15:50 -0500, Joe Landman wrote: > > Thomas J. Baker wrote: > > > Any help greately appreciated. Here are the details: > > > > > > [root@node002 ~]# ./examineRAIDDisks > > > mdadm -E /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1 /dev/sdf1 /dev/sdg1 /dev/sdh1 /dev/sdi1 /dev/sdj1 /dev/sdk1 /dev/sdl1 /dev/sdm1 /dev/sdn1 /dev/sdo1 /dev/sdp1 /dev/sdq1 /dev/sdr1 /dev/sds1 /dev/sdt1 /dev/sdu1 /dev/sdv1 /dev/sdw1 /dev/sdx1 /dev/sdy1 /dev/sdz1 /dev/sdaa1 /dev/sdab1 /dev/sdac1 > > > /dev/sdb1: > > > Magic : a92b4efc > > > Version : 00.90.00 > > > > Hi Thomas: > > > > Don't you need 1.0 or higher superblocks to make this work? > > > > Joe > > The array was made probably two years ago and had been working fine > until recently. In reading the documentation for mdadm, it did seem like > it should have required me to use the higher version but it never > complained when I made it and worked fine. > > Thanks, > > tjb Actually, rereading it makes me think it's OK. There are only 27 devices in the array and one hot spare. Each device is only 300GB, less than the 2TB limit. 0, 0.90, default Use the original 0.90 format superblock. This format limits arrays to 28 component devices and limits compo- nent devices of levels 1 and greater to 2 terabytes. I'll admit I could be misunderstanding something here. Thanks, tjb -- ======================================================================= | Thomas Baker email: tjb@unh.edu | | Systems Programmer | | Research Computing Center voice: (603) 862-4490 | | University of New Hampshire fax: (603) 862-1761 | | 332 Morse Hall | | Durham, NH 03824 USA http://wintermute.sr.unh.edu/~tjb | =======================================================================