Hi I think you will find that the RAID has not been built correctley. Take the second disk out of service and remove, reboot, and try to log in. You may need to 'clear the sockets' of the disk before you can rebuild the RAID. This is done by powering down the controller, physically removing both disks and powering up the controller, after 30 second switch off, reinsert disk 1 and boot up, once booted insert disk two and follow normal mirroring proceedure.
Hope this helps