designating anyone of {TAIL ~ the plurality} of {HEAD ~ storage} arrays as a primary device of the CSA 
designating anyone of { TAIL ~ the plurality } of { HEAD ~ storage } arrays as a primary device of the CSA
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH