From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Tyler J. Wagner" Subject: alignment of metadata 1.2 and mkfs.ext4 Date: Wed, 06 Jul 2011 08:10:46 +0100 Message-ID: <1309936246.11661.7.camel@baal> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi all (well, Neil, really), The the following, Neil states that that is no issue with alignment of metadata 1.2 and mkfs.ext4 on 4K drives: http://www.issociate.de/board/post/507176/filesystem_on_mdadm_raid_from_unpartioned_block_devices.html Sorry to ask again, but I just want to clarify. Metadata 1.2 puts the data 4K from the start of the device/partition. Does mkfs put the start of the filesystem at 64K from the start? IE, will the following align, without any need for options? (create partitions starting 2048 512-byte sectors from start = 1MB) mdadm --create /dev/md0 -v --raid-devices=4 --level=raid10 --metadata=1.2 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 mkfs.ext4 /dev/md0 And, slightly off-topic, it's not necessary to define stride and stripe any longer? mkfs.ext4 -E stride=16,stripe-width=32 /dev/md0 Regards, Tyler -- Tyler J. Wagner Chief Technical Officer, Talia Ltd http://www.talia.net email: tyler@talia.net mobile: +44 790 863 1442 office: +44 203 3181 500 x503 fax: +44 207 631 3343