My english is not very good so dont blame me ;)
I have juste recover my mybook with mbr from rescue procedure and the image files from christoff4444. The other mbr fils didn't boot and the image files from rescue procedure work fine too.
But ! When I make or the systeme make a linear raid the total space see with mdadm -Q and -D is +- 748Gb and the space in /proc/mdstat is +-2980Gb. I m using 2x 1500Gb seagate drive partionned and formated like the procedure of christoff4444 and i have try all methode to make it. But my effor were fruitless and all the time I get a linear raid with +-748Gb.
For now I have mounted /dev/sda4 in /shares/internal and /dev/sdb4 in /shares/internal2 created PUBLIC, PUBLIC2 and configured to use it as share.
I guess for a driver issue or maybe a file to edit but i m not linux expert. If someone can show me the way to have a linear raid with all disk space :)