From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Turmel Subject: Re: Mounting array at boot - works with some kernels but not others Date: Sun, 03 Apr 2011 13:41:10 -0400 Message-ID: <4D98B136.1010803@turmel.org> References: <4D98AAD3.2050700@turmel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Dennis Grant Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 04/03/2011 01:26 PM, Dennis Grant wrote: > On Sun, Apr 3, 2011 at 1:13 PM, Phil Turmel wrote: > >> On-list is fine. A couple of clarifications below: > >> Please do "mdadm --examine" on the component devices /dev/sda5 and /dev/sdb5. > > As requested: > > sudo mdadm --examine /dev/sda > mdadm: No md superblock detected on /dev/sda. > > sudo mdadm --examine /dev/sdb > mdadm: No md superblock detected on /dev/sdb. > Hmmm. This means that the metadata location is *not* ambiguous, or it would show for the examine of both the whole device and the partition. So much for that idea. >> Please also share the output of "blkid" so we can interpret this fstab. > > sudo blkid [snip /] > /dev/md1: UUID="cdd97ad2-e070-477b-b649-83921f70b9cf" TYPE="ext3" This is what I wanted, but I'm a dunce. You called out /dev/md1 directly in the fstab. Sorry. >> I suspect that the new kernels are noticing your version 0.90 metadata and trying to be conservative. 0.90 metadata can be ambiguous when on the last partition of a disk (same location and content as if for the whole disk). > >> You can remove the ambiguity by declaring in mdadm.conf that devices to inspect must be partitions, like so: >> >> DEVICE /dev/sd*[0-9] >> >> Or call them out explicitly: >> >> DEVICE /dev/sda5 /dev/sdb5 > > Here's the current version: > > cat /etc/mdadm/mdadm.conf > # mdadm.conf > # > # Please refer to mdadm.conf(5) for information about this file. > # > > # by default, scan all partitions (/proc/partitions) for MD superblocks. > # alternatively, specify devices to scan, using wildcards if desired. > DEVICE /dev/sda5 /dev/sdb5 > > # auto-create devices with Debian standard permissions > CREATE owner=root group=disk mode=0660 auto=yes > > # automatically tag new arrays as belonging to the local system > HOMEHOST > > # instruct the monitoring daemon where to send mail alerts > MAILADDR root > > # definitions of existing MD arrays > ARRAY /dev/md1 devices=/dev/sda5,/dev/sdb5 > > ------------------------- > So it looks like they are already called out. Yup. Blind alley. You mentioned that the system will boot with a newer kernel, just without the array. Could you boot it like that, but select single-user mode? Then you can save the dmesg to a file, collect any other useful messages, reboot into 2.6.31, then paste the files into an email. Phil