adjusting at least a portion of the one of the storage spaces for {HEAD ~ the logical data volume} to maintain {TAIL ~ the performance capabilities} of each of the storage arrays within the predetermined range, 
adjusting at least a portion of the one of the storage spaces for { HEAD ~ the logical data volume } to maintain { TAIL ~ the performance capabilities } of each of the storage arrays within the predetermined range ,
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH