From mboxrd@z Thu Jan 1 00:00:00 1970 From: Veljko Subject: Re: Linear device of two arrays Date: Thu, 20 Jul 2017 23:40:30 +0200 Message-ID: References: <20170705214250.0ea99538@natsu> <595D2ADA.8010907@youngman.org.uk> <5afd5cea-06b8-8524-e4f5-8534f23bd714@hardwarefreak.org> <87van15j9b.fsf@notabene.neil.brown.name> <87o9sn232n.fsf@notabene.neil.brown.name> <1eefd627-1aba-a795-05f0-d2106d3a62a3@gmail.com> <87shhyzhg5.fsf@notabene.neil.brown.name> <38e015fa-a07c-8f1a-3a04-384d973966be@gmail.com> Reply-To: veljko3@gmail.com Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org, neilb@suse.com List-Id: linux-raid.ids On Tue, Jul 18, 2017 at 10:58 AM, Veljko wrote: > On 07/17/2017 12:16 PM, Veljko wrote: >> >> On 07/15/2017 02:12 AM, NeilBrown wrote: >> >>> So command should be >>> >>>>> dd if=/dev/md2 of=SOMEWHERE/SAFE bs=1M skip=5626590 >>> >>> >>> and expect it to create a 3M file. >>> >>> Use this 'skip' number of the 'seek' number later. >>> >>> NeilBrown >> >> >> Thanks, Neil, now it makes more sense. >> >> I tried to create new linear device, but mdadm is complaining about >> data-offset: >> >> # mdadm -C /dev/md4 -l linear -n 2 --rounding=1M -e 1.0 --data-offset=0 >> /dev/md2 /dev/md3 >> mdadm: invalid data-offset: 0 >> >> I'm using Debian 8.8 if it makes any difference. >> >> # mdadm -V >> mdadm - v3.3.2 - 21st August 2014 >> >> What could be the problem? > > > I noticed that md2 and md3 use 1.2 metadata. Can that be the issue? Trying > to create 1.0 metadata for md4? Any advice on this?