Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759010AbZGIBFb (ORCPT ); Wed, 8 Jul 2009 21:05:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755908AbZGIBFN (ORCPT ); Wed, 8 Jul 2009 21:05:13 -0400 Received: from mail.lang.hm ([64.81.33.126]:54005 "EHLO bifrost.lang.hm" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755088AbZGIBFM (ORCPT ); Wed, 8 Jul 2009 21:05:12 -0400 Date: Wed, 8 Jul 2009 18:05:06 -0700 (PDT) From: david@lang.hm X-X-Sender: dlang@asgard To: linux-kernel cc: linux-raid@vger.kernel.org Subject: Re: partition detection problem on 2.6.29.1 and 2.6.30 In-Reply-To: Message-ID: References: User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; FORMAT=flowed; CHARSET=US-ASCII Content-ID: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2058 Lines: 55 I managed to track the problem down. it turns out that at some point someone created a md array using the raw devices instead of the partitions. it looks like the kernel autodetection for raid kicked in prior to the partition detection and after it claimed the drives the partition detection was never given a chance to do so. this is logical, but it makes the dmesg output that appears to be identifying the paritions _very_ misleading. David Lang On Wed, 8 Jul 2009, david@lang.hm wrote: > Date: Wed, 8 Jul 2009 14:35:41 -0700 (PDT) > From: david@lang.hm > To: linux-kernel > Subject: partition detection problem on 2.6.29.1 and 2.6.30 > > I have a system that has a large number of drives in it (45), and it's had a > problem with banks of disks getting disconnected from it. > > however, when I started looking into it today (after another sysadmin worked > on it for a while), I found that the system is not able to access the > partitions on the drives. > > if I am reading dmesg correctly it is seeing the partitions during boot, and > if I do 'fdisk -l' it lists all the paritions correctly, but if I try to do a > > dd if=/dev/sdb1 of=/dev/null count=1 > > I get the error "dd: opening `/dev/sdb1': No such device or address" > > #ls -l /dev/sdb1 > brw-rw---- 1 root disk 8, 17 Nov 7 2006 /dev/sdb1 > > I removed udev and setup nodes manually to eliminate any possibility that it > was a problem there. > > the attachment partitions.missing.partitions is a cat of /proc/partitions > > sysfs shows all the drives but none of the partitions. > > if I run fdisk and do a write (which runs the ioctl to re-read the parition > table) the system detects the partition and is able to access it until the > next reboot. > > what is going on here? > > David Lang -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/