On 18 Feb 2016 09:51 +0100, from florian.dotzer@xxxxxx (Florian Dotzer): > <html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div><br/> Please resend as not HTML. > @Michael , Arno , Sven :<br/> > <br/> > Thanks for your replies and the help you are offering . Thats real support compared to experience with QNAP support ;-))<br/> > I *can* login as root to the QNAP box - but I am not a shell guru .<br/> > I hope I will be able to unlock my LUKS Copntainer without losing my Data .<br/> > <br/> > I used the graphical GUI of QNAP which offered this possibility to add a disk to an existing RAID ,<br/> > e.g. I clicked a Button named "Add hard drive" in the RAID Management Section ,<br/> > selected the newly added disk, and waited for the desaster to complete<br/> > <br/> > (german slang : mausi klickibunti ) .<br/> > <br/> > Somehow the command output was written to the Device and not elsewhere (/dev / null or shell )<br/> > <br/> > Michael wrote :<br/> > > What was the exact device layout?<br/> > > Physical storage then MD RAID<br/> > Yes. I have the box not at my desk here. Sorry.<br/> > <br/> > > then LUKS<br/> > At least I found a corrupted LUKSHeader there in /dev/md0<br/> > <br/> > > then some file system,<br/> > I hope so , thats where my data lives .<br/> > <br/> > YESS Sir<br/> > <br/> > > or physical storage then LUKS then MD RAID<br/> > >then some file system, or some other arrangement?<br/> > No<br/> > <br/> > >What was the exact command used to "add a disk"?<br/> > QNAP may know it , I not. I didnt find anything in dmesg / kernel log or elsewhere .<br/> > <br/> > From the best of my limited knowledge as I interpret the findings when I login as root in the cli ,<br/> > I see the RAID created with mdadm as built dirctly on the disk partitions sd[d|e|f|g|h|c]3<br/> > <br/> > where /dev/sdc is the disk I added .<br/> > the raid itself is up with all disks , (all disks 'U' ) , valid / valid superblock<br/> > I can get and read data from the block device /dev/md0<br/> > as you have seen in my last email.<br/> > <br/> > <br/> > <br/> > @ Arno :<br/> > <br/> > > What did you do?<br/> > > Did you pipe the output from mdadm into /dev/md0?<br/> > No.<br/> > > If so, there might be a chance to recover this.<br/> > <br/> > > First, make that header backup now, if you have not already.<br/> > <br/> > I have at least the first 64 MB of /dev/md0 extracted with dd if=/dev/md0 of=of=file_with_first_64_MB_of_md0 bs=1024 count=65535<br/> > The hex Dump was extracted from this .<br/> > I hope that is enough for a header backup (approx. 2MiB + xxx as stated in the FAQ) ?<br/> > <br/> > > The data that is missing depends on the QNAP device.<br/> > SS839 PRO<br/> > > Defaults can be changed on compile.<br/> > I only have binaries , no sources , no compiler<br/> > > Easiest option is<br/> > > likely to make a new LUKS container on it and try what<br/> > > is in there. You should be able to use the loop-device<br/> > > procedure from FAQ Item 2.6 from the commandline for<br/> > > that. If those values do not work, next option is to<br/> > > have the QNAP create a LUKS container on a new disk<br/> > > and see what it does.<br/> > <br/> > I'll try it that weekend or next when I have time to do it .<br/> > <br/> > <br/> > @Sven :<br/> > <br/> > >btw: I agree, if just the short output of mdadm was written to the disk<br/> > >chances are quite good for recovery.<br/> > <br/> > I hope so. I tried dd on files to replace the first 512 bytes of a file , but<br/> > the target file was completely replaced with this command :<br/> > <br/> > dd if=512_bytes_with_fixed_header of=file_with_first_64_MB_of_md0 bs=512 count=1<br/> > <br/> > Now I dont know if dd's behaviour is different on block device level ,<br/> > or is there another better way to replace / correct the first bytes of /dev/md0 ?<br/> > <br/> > <br/> > Greetings , Florian<br/> > </div></div></body></html> -- Michael Kjörling • https://michael.kjorling.se • michael@xxxxxxxxxxx “People who think they know everything really annoy those of us who know we don’t.” (Bjarne Stroustrup) _______________________________________________ dm-crypt mailing list dm-crypt@xxxxxxxx http://www.saout.de/mailman/listinfo/dm-crypt
