writing the predetermined data to a log block corresponding to {HEAD ~ a data block} containing {TAIL ~ the page} 
containing
writing the predetermined data to a log block corresponding to { HEAD ~ a data block } containing { TAIL ~ the page }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL