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