This categorization can be based on dividing the requests between write and read requests, or between {HEAD ~ requests} that alter {TAIL ~ data} stored on the storage device and requests that do not alter data on the storage device 
alter
This categorization can be based on dividing the requests between write and read requests , or between { HEAD ~ requests } that alter { TAIL ~ data } stored on the storage device and requests that do not alter data on the storage device
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH