Reminds me what ATA over Ethernet[0] promised. I bought one of Coraid's Parallel IDE to 100mbit single-device developer kits to experiment with, and then attempted to use their blade software to serve up mdadm devices. Worked okay for short periods of time (5-10 minutes) before the client machines would throw a wobbly and irrecoverably corrupt the filesystem (tried both XFS and JFS) on the device.