As the size of data storing arrays of disks grows, it becomes vital to protect data against double disk failures. An economic way of providing such protection consists of adding two disks to the array. The increased storage capacity of the array is used to store the information necessary for the recovery of all data in the case any two disks fail (RAID-6). A popular method of generating recovery information from data utilizes linear operations in the Galois field GF(28 ). Mathematically, this solution is equivalent to using the Reed-Solomon (RS) code with two parity words. Its principle advantage is based on simplicity of the basic operations in a field extension of the primary field GF(2): addition is just bitwise XOR, while multiplication can be constructed using shifts, AND's and additions. The RS code with two parity words is an example of a linear block code capable of correcting up to two errors in known positions per block. In the paper we construct alternative examples of ...
R. Jackson, D. Rumynin, O. Zaboronski