A New Method to Cope with the Small Write Problem in RAID - Using Reed-Solomon Code

摘要

On the advanced RAID system, EVENODD code has been found as an important algorithm on disk failure recovery for single error or double erasure correction. However, the EVENODD code has major problem on multiple modes of operations to solve random error and erasures. A small write problem is also an important factor to influence the performance of the RAID. The RS (Reed-Solomon) code is ignored at the time of RAID design, due to the complex operations in decoder. Since Jing proposed a RS-RAID system using fast math modules on, such design is feasible to apply RS code on VLSI. Further improved algorithms are developed to reduce the complexity of the circuit of RS encoder and decoder on, The new method developed in this paper solves the small write problem by simply replacing the new data and modifying the parity symbols. So, a frequent write data and its parity are transparently updated through a VLSI implementation.