From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from localhost (dhcp-100-19-150.bos.redhat.com [10.16.19.150]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p46FLUBk016694 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Fri, 6 May 2011 11:21:31 -0400 Date: Fri, 6 May 2011 11:21:30 -0400 From: Mike Snitzer Message-ID: <20110506152129.GA25531@redhat.com> References: <4DC40BFD.3080408@cfl.rr.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4DC40BFD.3080408@cfl.rr.com> Subject: Re: [linux-lvm] getting pe_start right Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: LVM general discussion and development On Fri, May 06 2011 at 10:55am -0400, Phillip Susi wrote: > While trying to convert my mdadm raid5 array from metadata format > 0.9 to 1.0, I forgot to specify the version and it defaulted to 1.2, > which damaged the lvm metadata. After correcting mdadm to 1.0, I > decided to try to recreate the LVM after managing to locate the > volume descriptions in the metadata after manually dumping it. > > The problem I now have is that pvcreate will not use the same > pe_start as before. It was 384 and it is now 3072. I tried using > --metadatasize 192k --dataalignmentsize 0 and it did not help. What > gives? Would be quite helpful if you shared kernel and lvm2 version info... chances are lvm2's data_alignment_detection will shift the data start to the start of the next full stripe of the raid5. You should be able to specify the old start with: --dataalignment 192k --dataalignmentoffset 0 (--dataalignmentoffset 0 likely isn't needed, but it just overrides lvm2's data_alignment_offset detection if it just so happens that raid5 has alignment_offset!=0)