From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Robinson Subject: Re: unknown partition table starting with 2.6.28 Date: Tue, 02 Feb 2010 10:31:46 +0000 Message-ID: <4B67FF12.5070004@anonymous.org.uk> References: <4B51010E.9090800@vorgon.com> <4B51B46A.4080302@anonymous.org.uk> <4B673DAE.3040806@tmr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4B673DAE.3040806@tmr.com> Sender: linux-raid-owner@vger.kernel.org To: Linux RAID List-Id: linux-raid.ids On 01/02/2010 20:46, Bill Davidsen wrote: > John Robinson wrote: >> On 15/01/2010 23:58, Timothy D. Lenz wrote: >>> I am trying to update my kernel from 2.6.26.8 to the current .32. >> [...] >>> Starting with .28 I am getting an error about unknown partition table >>> for all 3 md's. md0 is boot and main programs, md1 is swap, md2 is >>> mostly recordings storage for vdr. All 3 are raid 1 and raid is built >>> in. >> >> Your md devices aren't partitioned so you can quite safely ignore the >> warning. See also http://marc.info/?l=linux-raid&m=125797242110594&w=2 > > To clarify that a bit, the kernel can use several partition formats, and > something in the partitions looks like a partition table but not a > *valid* partition table. So the kernel warns that it doesn't recognize > the table. > > I suspect that using a different superblock type would change (probably > eliminate) this, putting the md information at the start of the > partition, of in a bit or whatever makes the kernel happy. The kernel > would make us happy if it checked for a valid md superblock at the *end* > of the partition, but there may be reasons why that's undesirable. > > Finally, I'm less willing than John to say you can ignore it, any time > something comes close enough to working (in an undesired way) to > generate an error message, if there's a simple way to be sure the kernel > doesn't try to use random data as a partition table, you might well want > to take a step to prevent a problem now. > > I believe it arises out of all arrays being partitionable recently, > again the details don't come to mid, I've been pretty head down on > another project since November. I don't think this analysis is correct. Yes, the situation has arisen out of all arrays - in fact all block devices - being partitionable, but the warning's not because of something that looks like a dodgy partition table, it is precisely what it says, a statement that the device does not contain a valid partition table. I am essentially repeating the contents of Doug Ledford's earlier post to this list, to which I referred above. Cheers, John.