It would appear that this particular disk has previously been used on an nvidia controller and the metadata remains on the disk. Try this to delete the nvidia metadata:
sudo dmraid -E -f nvidia /dev/sda
You may need to repeat for /dev/sdb.
It would appear that this particular disk has previously been used on an nvidia controller and the metadata remains on the disk. Try this to delete the nvidia metadata:
sudo dmraid -E -f nvidia /dev/sda
You may need to repeat for /dev/sdb.