Inexpensive, reliable hard disk storage is increasingly required in both businesses and the home. As disk capacities increase and multiple drives are combined in one system the probability of multiple disk failures increases. Through the adoption of RAID 6 the capability to recover from up to two simultaneous disk failures becomes available. In this article, we present three different RAID 6 implementations each tailored to support different target applications and optimized to reduce overall hardware resource utilization. We present an optimal Reed-Solomon-based RAID 6 implementation for arrays of four disks. We also present the smallest in terms of hardware resource utilization as well having the highest throughput RAID 6 hardware solution for disk arrays of up to 15 drives. Finally, we present an implementation supporting up to 255 disks in a single array.

Hard disk storage capacity has continued to rise whilst at the same time the cost per megabyte continues to fall. This, combined with increased usage of digital storage for documents, photography and video for both home and business use has led to increased need for reliable data storage system. Redundant arrays of inexpensive disks (RAID) have proven to offer the best characteristics for reliable storage. However, to date RAID based systems have been limited by their support for only single disk erasure tolerance.This paper introduces an efficient hardware RAID 6 controller on an FPGA capable offering support for uninterrupted access during double disk erasures and recovery.

Hard disk storage capacity has continued to rise whilst at the same time the cost per megabyte continues to fall. This, combined with increased usage of digital storage for documents, photography and video for both home and business use has led to increased need for reliable data storage system. Redundant arrays of inexpensive disks (RAID) have proven to offer the best characteristics for reliable storage. However, to date RAID based systems have been limited, due to cost and circuit complexity, by their support for only single disk erasure tolerance. FPGAs allow us to overcome these difficulties and allow support for more complex storage algorithms. This paper introduces an efficient FPGA based hardware RAID 6 accelerator providing uninterrupted access during all single and double disk erasures and recovery