While these changes are in progress, the disk array remains on line and {HEAD ~ most host data} is available for {TAIL ~ access} and modification 
While these changes are in progress , the disk array remains on line and { HEAD ~ most host data } is available for { TAIL ~ access } and modification
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH