The data are migrated into {TAIL ~ RAID 5 configurations} as a background operation, to minimize {HEAD ~ the disk space} lost 
The data are migrated into { TAIL ~ RAID 5 configurations } as a background operation , to minimize { HEAD ~ the disk space } lost
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH