Mirrored Volume (RAID-1)
A mirrored dynamic volume is a fault-tolerant volume that duplicates your data on two or more physical disks. A mirror provides redundancy by simultaneously writing the same data onto two or more separate mirrors (or plexes) that reside on different disks. If one of the disks fails, data continues to be written to and read from the unaffected disk or disks. SFW supports up to 32 mirrors.
In contrast, the mirrored volumes originally created in Disk Administrator and supported for use on basic disks have only two mirrors.
A mirrored volume is slower than a RAID-5 volume in read operations but faster in write operations. You can create mirrored volumes only on dynamic disks. In SFW, you can extend mirrored volumes.