A RAID-5 volume is a fault-tolerant volume with data and parity striped alternately across three or more physical disks. If one of the physical disks fails, data that was on the failed disk is recreated from the remaining data and parity on the other disks. RAID-5 volumes are a good solution for data redundancy in a computer environment in which most activity consists of reading data.

You need a minimum of three disks for a RAID-5 volume. Storage Foundation can accommodate up to 256 disks in a RAID-5 volume. You can extend a RAID-5 volume, but it cannot be mirrored.