Disk Duplexing Disk Mirroring differences

"Disk Mirroring" uses only one disk controller where as disk duplexing option uses additional disk controller. In RAID 1 aka Disk Mirroring, one drive in the array acts as "Mirror" drive, backing up all the data on the primary drive on-the-fly.

"Duplexing" option adds another disk controller, in case one controller fails, the other controller will take over automatically with out any interruption in the service.