2015-12-14 13:55 GMT+01:00 Phil Turmel <philip@xxxxxxxxxx>: > On 12/14/2015 07:03 AM, TheGerwazy . wrote: > >> Hi Phil >> Thanks for the message .... but, >> In the last version of mdadm I get: >> >> ./mdadm --create --raid-devices=8 --level=6 --assume-clean /dev/md7 >> /dev/mapper/ovsdb1:1024 /dev/mapper/ovsdc1:4096 >> /dev/mapper/ovsdd1:1024 /dev/mapper/ovsde1:1024 >> /dev/mapper/ovsdf1:1024 /dev/mapper/ovsdg1:1024 >> /dev/mapper/ovsdh1:1024 /dev/mapper/ovsdi1:4096 >> mdadm: cannot open /dev/mapper/ovsdb1:1024: No such file or directory > > The final version of that feature requires --data-offset=variable before > the :offset syntax is recognized on the devices. > >> sudo ./mdadm --create --raid-devices=8 --level=6 --assume-clean > >> mdadm: array /dev/md7 started. > > You're committed now. I hope it works out for you. > >> BTW is it possible to find right data offset without superblock on drive ? > > Only if the content of that member device has searchable content in a > predictable location. In practice that means finding the offset of the > first member by locating filesystem magic, or otherwise locating the > transition from all zeros to randomish data. > > Good luck. > > Phil > "Good Luck" seems to be working ... ;) I finally recovered files with magic cmd: sudo ./mdadm --create --raid-device=8 --level=6 --assume-clean --size=974508544 /dev/md7 /dev/mapper/ovsde2:1024 /dev/mapper/ovsdh1:100352 /dev/mapper/ovsdg1:100352 /dev/mapper/ovsdc1:131072 /dev/mapper/ovsda1:1024 /dev/mapper/ovsdb1:1024 /dev/mapper/ovsdf1:131072 /dev/mapper/ovsdd1:100352 The main problem is the data offsets are not stored elsewhere than in superblock. I have some drives from debian 6.0.5 and some were changed in debian 7.5. In 6.0.5 default data offset was at 2048 sector while int 7.5 it is 262144. But - when add new drive to existing array and partition (or drive) is smaller than 262144 plus array data (array device size) when mdadm calculates something between 2048 and 262144. -> so as above magic cmd's in my case it was 200704 sector. I recovered it by doing all steps regarding mdadm in virtual enviroment and I am surprised by the non standard data offsets. Thanks for Phil regards Gerard -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
