RAID 6: RAID 6 provides fault tolerance by using double parity, allowing the system to withstand two simultaneous drive failures. It offers higher fault tolerance compared to RAID 5, which only tolerates a single drive failure. Although RAID 6 has a write performance penalty due to the additional parity calculations, it provides a good balance between capacity and high fault tolerance, which is critical for the customer.
References:
RAID 6 Overview