model: LS420D
firmware: Version 1.85-0.01
one of the WD Green 4TB drives failed on my RAID1 array.
since this device is 3 years old, i choose to buy two new 6tb drives.
i wanted to replace the bad one (bay 2), let the array rebuild, then replace the other drive (bay 1).
when i put the new 6tb drive in bay 2, it's not giving me the option to rebuild the array.
can someone point me in the right direction?