From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.server123.net (Postfix) with ESMTPS for ; Tue, 24 Nov 2015 12:15:32 +0100 (CET) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1a1BZD-0007bO-RK for dm-crypt@saout.de; Tue, 24 Nov 2015 12:15:23 +0100 Received: from 93.102.85.179.rev.optimus.pt ([93.102.85.179]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 24 Nov 2015 12:15:23 +0100 Received: from l-alexandre by 93.102.85.179.rev.optimus.pt with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Tue, 24 Nov 2015 12:15:23 +0100 From: Luis Alexandre Date: Tue, 24 Nov 2015 11:15:18 +0000 Message-ID: References: <20151121184914.GA28647@tansi.org> <5651B1CF.7090306@sapo.pt> <20151122125233.GA4802@tansi.org> <5651D9B3.6000500@sapo.pt> <565241FF.90005@whgl.uni-frankfurt.de> <20151123033504.GA12468@tansi.org> <56528E72.8090604@whgl.uni-frankfurt.de> <20151123062627.GA14309@tansi.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit In-Reply-To: <20151123062627.GA14309@tansi.org> Subject: Re: [dm-crypt] Open raid1 with luks encryption after a raid re-create List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: dm-crypt@saout.de Dear Arno and Sven, Thanks very much for your support. I was able to open the copy I made with tail -c +135266305 /dev/sdx > /dev/sdy and cryptsetup luksOpen /dev/sdy e1 and have all my data back. Thanks again for your support. Best regards, Luis On 23-11-2015 06:26, Arno Wagner wrote: > On Mon, Nov 23, 2015 at 04:56:34 CET, Sven Eschenberg wrote: >> >> >> Am 23.11.2015 um 04:35 schrieb Arno Wagner: >>> On Sun, Nov 22, 2015 at 23:30:23 CET, Sven Eschenberg wrote: >>> [...] >>>> Now to your question, once you know the offset of the header: >>>> 1.)Setup a loop device from your image (You can use an offset into >>>> the image where your loop device starts with sector 0) see --offset >>>> in losetup man page. >>> >>> Ah, yes. That would save copying it. >> >> That was the plan. In general using dmsetup to create a mapping >> manually should work too, if loop device support is missing - >> dmsetup is pretty cryptic to use though. > > "Cryptic" is not good here... > > I was not aware that losetup allows read-only mappings, or I > would probably have looked at it too. > > Excellent! So I learned something too! > >>>> Inspect loopdevice if the LUKS Header now is on sector 0 >>>> 2.)Try a cryptsetup luksopen in readonly mode >>> >>> Good idea. With that it may be reasonaly safe to work >>> with the original disk. I still would make a full >>> backup before. >>> >>> Regards, >>> Arno >>> >> >> Well, I thought about using the loop on the file while the physical >> disk stays unchanged. Otherwise it would be possible to work on the >> physical disk, and keep a safety image. No matter which way one >> chooses, always have a safety copy. >> >> If the disk is having mechanical problems or something similiar one >> would of course use 2 images, one 'master binary backup' and the >> replica to work on. >> >> Once mapping and opening works, one can choose to either copy out >> the files and backup (usually a good idea) or to create a copy in >> the manner you described. Possibly such an image could then be >> remerged onto a new clean array, if it is otherwise intact. Not >> without some remaining risks though. > > Indeed. And first things first, lets see whether that header is > viable before goping any further. > > Regards, > Arno >