... if you use them with disks larger than 2TB
This just happened to a friend of mine. He had two 3 TB disks in a RAID-1 configuration, attached to an older Marvell RAID controller. (But the manufacturer really doesn't matter). Suddenly Windows started complaining about being unable to access folders and then the disk completely went away. Disk management just shows it as "unformatted". However both disks report as OK. What happened?