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 -- Arno Wagner, Dr. sc. techn., Dipl. Inform., Email: arno@xxxxxxxxxxx GnuPG: ID: CB5D9718 FP: 12D6 C03B 1B30 33BB 13CF B774 E35C 5FA1 CB5D 9718 ---- A good decision is based on knowledge and not on numbers. -- Plato If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
