On Tue, Sep 14, 2010 at 08:50:19PM +0200, Ma Begaj wrote: > > Hi, > > > > On Tue, Sep 14, 2010 at 06:55:36PM +0200, Ma Begaj wrote: > >> Hi, > >> > >> > >> I got a new HDD a few days ago and I put it in an external case and connected > >> it over USB with my home server. It is a 2000GB WD disk, ?WD20EARS. > > > > That would be one of the 2kB sector drives... > > you mean 4kb? Yes ;-) > > > >> I already read a few articles how should I format this "special" > >> drive, and I did it like this: > >> http://ubuntuforums.org/showthread.php?t=1456251 > >> > >> I set the partition to begin on sector 64 (instead of 63), run > >> luksFormat, run luksOpen, > >> created XFS and copied my files on this disk. I umounted it later and > >> I rebooted > >> the server today. > >> > >> First thing I noticed is that disk/paritions are not visible in > >> /dev/disk/by-uuid/ although > >> /dev/sdm and /dev/sdm1 are available. fdisk also does not look same > >> as before: > > > > Not good. > > > >> fdisk output: > >> -------------- > >> root@road:/dev/disk/by-uuid# ?fdisk /dev/sdm > >> > >> The number of cylinders for this disk is set to 243201. > >> There is nothing wrong with that, but this is larger than 1024, > >> and could in certain setups cause problems with: > >> 1) software that runs at boot time (e.g., old versions of LILO) > >> 2) booting and partitioning software from other OSs > >> ? ?(e.g., DOS FDISK, OS/2 FDISK) > >> > >> Command (m for help): p > >> > >> Disk /dev/sdm: 2000.3 GB, 2000398934016 bytes > >> 255 heads, 63 sectors/track, 243201 cylinders > >> Units = cylinders of 16065 * 512 = 8225280 bytes > >> Disk identifier: 0x00000000 > >> > >> ? ?Device Boot ? ? ?Start ? ? ? ? End ? ? ?Blocks ? Id ?System > >> /dev/sdm1 ? ? ? ? ? ? ? 1 ? ? ?243202 ?1953514552 ? 83 ?Linux > > > > You did create one large partition? > > yes just one filling whole disk. > > > > > > What is the output of "fdisk -lu /dev/sdm1"? > > > > root@road:/dev/disk/by-uuid# fdisk -lu /dev/sdm1 > > Disk /dev/sdm: 2000.3 GB, 2000398934016 bytes > 255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors > Units = sectors of 1 * 512 = 512 bytes > Disk identifier: 0x00000000 > > Device Boot Start End Blocks Id System > /dev/sdm1 64 3907029167 1953514552 83 Linux > > Well, it looks good. Indeed. Now there is the question why cryptsetup fails and the partition is not detected. > > > > > >> -------------- > >> > >> "Start" is 1 instead of 64.... pretty strange because I set it to 64 > >> when I was making this partition. > > > > You set it to 64 sectors. The 1 is a cylinder. You cannto see in this > > view where exactly the partition starts. Use the -u option to fdisk. > > Good to know. Thanks. > > > > > > >> > >> luksOpen does not work and luksDump/isLuks reported that /dev/sdm1 is > >> not luks partition. > > > > Interesting. > > > >> I have cryptsetup 1.0.5 on my server. > > > > Aehm, that is hiostoric. Please try with the current one, > > which would be 1.1.3. > > Right now before continuing with the rest? I have 3 other luks > partitions on this machine. Should I expect some hiccups? > > I am planning to upgrade whole system in the next week and > if possible I will wait until than. Hmm. Better wait. Therw was some issue that could hit you if you have other LUKS partitions. I am honestly not sure whether it applies. > > > > >> There are two questions for me here: > >> 1. I have luksDump of /dev/sdm1 before this happened. Can I use > >> luksDump ouput ?to > >> recover/overwrite Luks partition? > > > > I think not, but I am not sure. Before trying that, lets figure > > out whether this is simply an offset issue. Can you look > > through the start of the disk and give the offset where the > > "LUKS" string is exactly? > > > > Something like this should do the trick: > > > > hd /dev/sdm | grep LUKS > > "hd"? I don't have hd command on my server. HexDump. > but I found the position with with dd and vi: > > dd if=/dev/sdm of=/tmp/sdm bs=32256 count=1 obs=10240 skip=1 > > > this gives me LUKS on the beginning of /tmp/sdm so offset should be 32256: > > LUKS??^@^Aaes^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@cbc-essiv:sha256^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@sha1^@^@^@^@^@^@^@^@^@^ > @^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^@^D^H^@^@^@^Pq^W:<93>CE?????k?)?Ql?<8f>??0?<9b>m^Yr > ?^E > > > and like this: > root@road:/dev/disk/by-uuid# dd if=/dev/sdm of=/tmp/sdm bs=1024000 count=1 > 1+0 records in > 1+0 records out > 1024000 bytes (1.0 MB) copied, 0.0327064 s, 31.3 MB/s > root@road:/dev/disk/by-uuid# grep -ob --binary-files=text LUKS /tmp/sdm > 32256:LUKS > > or grep directly on /dev/sdm > > [ 32256 ] should be offset. > > > What should I do with this? This confirms that you did create the LUKS container at the right place, namely the LUKS header is at 64 x 512 B offset. This seems to be some bizzarre issue with your system not detecting the partitions right and LUKS is actually working as expected. Ok, lets do some triage. - What Linux, what kernel version? - Any special set-up like virtuzlization? - Any special partition management system? > > > >> fdisk reports "start" on sector 1 instead of 64, which means that > >> something there went wrong. > > > > No, see above. > > > >> Or not? Ideas? If I can use luksDump to recover luks-header should the > >> partition table maybe be > >> rewritten beginning with sector 64 before I recreate luks header. > >> > >> > >> 2. How all this could happen? > >> > >> I would be very happy to experiment with this, to repeat all the steps > >> to recreat the situation > >> ?if I know that I am able to recover my partition. Any ideas before I > >> start to play with this? > >> How much of the partition header should I backup before starting with > >> all of this? > > > > See the FAQ. If you back up the first 100MB, you are on the safe side. > > > > root@road:/dev/disk/by-uuid# dd if=/dev/sdm of=/root/sdm.iso > bs=1024000 count=100 > 100+0 records in > 100+0 records out > 102400000 bytes (102 MB) copied, 3.01704 s, 33.9 MB/s Yes, like that. > > >> > >> p.s. I have all the data but I would like to avoid copying again > >> because I have to copy everything > >> (over 500gb) over SSH trough a 10mb connection > > > > Half a pound (500g) of 'b' though a 10 milli-bit connection? > > Sounds like a pain (yes, capitalization can carry meaning). > > ;-). believe me even 10[M]b is pretty slow if you have to copy 500[GB]. Hehe. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@xxxxxxxxxxx GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans 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
