The present invention is storage apparatus where an intermediary device is arranged between {TAIL ~ a controller} and a plurality of disk devices of different performances arranged in {HEAD ~ a hierarchical manner} 
The present invention is storage apparatus where an intermediary device is arranged between { TAIL ~ a controller } and a plurality of disk devices of different performances arranged in { HEAD ~ a hierarchical manner }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD