Logging RAID - An Approach to Fast, Reliable, and Low-Cost Disk Arrays

Parity-based disk arrays provide high reliability and high performance for read and large write accesses at low storage cost. However, small writes are notoriously slow due to the well-known read-modify-write problem. This paper presents logging RAID, a disk array architecture that adopts data logging techniques to overcome the small-write problem in parity-based disk arrays. Logging RAID achieves high performance for a wide variety of I/O access patterns with very small disk space overhead. We show this through trace-driven simulations.