If the number n of the requests being processed is less than 2 , control is passed to step 14, the LBA as a median point of {HEAD ~ the logical block address LBA} of {TAIL ~ the disk devices} 13 and 14 is calculated, and the obtained value is set as a boundary LBA 
of
If the number n of the requests being processed is less than 2 , control is passed to step 14 , the LBA as a median point of { HEAD ~ the logical block address LBA } of { TAIL ~ the disk devices } 13 and 14 is calculated , and the obtained value is set as a boundary LBA
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH