In another example, {HEAD ~ simple re replication} requires less write Input/Output operations than complete out migration, and is therefore a faster way to restore {TAIL ~ data redundancy} 
In another example , { HEAD ~ simple re replication } requires less write Input / Output operations than complete out migration , and is therefore a faster way to restore { TAIL ~ data redundancy }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL