From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Tyler J. Wagner" Subject: Re: alignment of metadata 1.2 and mkfs.ext4 Date: Wed, 06 Jul 2011 10:52:34 +0100 Message-ID: <1309945954.2685.2.camel@baal> References: <1309936276.11661.8.camel@baal> <20110706152016.1982c6fd@natsu> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110706152016.1982c6fd@natsu> Sender: linux-raid-owner@vger.kernel.org To: Roman Mamedov Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Wed, 2011-07-06 at 15:20 +0600, Roman Mamedov wrote: > On Wed, 06 Jul 2011 08:11:16 +0100 > "Tyler J. Wagner" wrote: > > > Metadata 1.2 puts the data 4K from the start of the device/partition. > > This is not correct. See mdadm -E /dev/sdX. > > $ sudo mdadm -E /dev/sdc3 > /dev/sdc3: > ... > Version : 1.2 > ... > Data Offset : 2048 sectors > ... That is very interesting. The mdadm man page, and everything I've seen online, all say "The different sub-versions store the superblock at different locations on the device, either at the end (for 1.0), at the start (for 1.1) or 4K from the start (for 1.2)." Regards, Tyler -- "Religion is the opiate of the masses, so long as the masses are straight. However, amass a bunch of lesbians and you're going to need actual drugs." -- OKCupid Blog, with apologies to Karl Marx http://blog.okcupid.com/index.php/gay-sex-vs-straight-sex/