From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Turmel Subject: Re: Mdadm with data offsets Date: Mon, 14 Dec 2015 07:55:20 -0500 Message-ID: <566EBC38.7060205@turmel.org> References: <566E0440.70801@turmel.org> <566E05B2.20803@turmel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: "TheGerwazy ." Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 12/14/2015 07:03 AM, TheGerwazy . wrote: > Hi Phil > Thanks for the message .... but, > In the last version of mdadm I get: > > ./mdadm --create --raid-devices=8 --level=6 --assume-clean /dev/md7 > /dev/mapper/ovsdb1:1024 /dev/mapper/ovsdc1:4096 > /dev/mapper/ovsdd1:1024 /dev/mapper/ovsde1:1024 > /dev/mapper/ovsdf1:1024 /dev/mapper/ovsdg1:1024 > /dev/mapper/ovsdh1:1024 /dev/mapper/ovsdi1:4096 > mdadm: cannot open /dev/mapper/ovsdb1:1024: No such file or directory The final version of that feature requires --data-offset=variable before the :offset syntax is recognized on the devices. > sudo ./mdadm --create --raid-devices=8 --level=6 --assume-clean > mdadm: array /dev/md7 started. You're committed now. I hope it works out for you. > BTW is it possible to find right data offset without superblock on drive ? Only if the content of that member device has searchable content in a predictable location. In practice that means finding the offset of the first member by locating filesystem magic, or otherwise locating the transition from all zeros to randomish data. Good luck. Phil