mdadm Device or resource busy not by dmraid

view story

http://serverfault.com – I have an issue with a new mdadm raid. When i try to: root@dys:~# mdadm --add --verbose /dev/md0 /dev/sdb1 mdadm: Cannot open /dev/sdb1: Device or resource busy dmraid i pointed as the usual problem but it's not even installed. Also tried to check it with lsof and no result. Im just out of ideeas the output of /proc/mdstat if of any help: root@dys:~# cat /proc/mdstat Personalities : [raid1] md1 : active (auto-read-only) raid1 sdb2[2] sda2[1] 7858164 blocks super 1.2 [2/2] [UU] md0 : active (auto-read-only) raid1 sda1[1] 968900472 blocks super 1.2 [2/1] [_U] unused devices (HowTos)