A Reliability Framework for Proactive-Tolerance Reed-Solomon Storage Systems^*

Reed-Solomon coding has been widely adopted to protect data storage against failures in storage systems. Recently, proactive fault tolerance is coming to offer an added protection for data storage coping with the increased device failures. Reliability is critical for storage systems. Due to complex system states and fault tolerance patterns, it is very intricate to analyze the reliability of proactive-tolerance Reed-Solomon storage systems. In this paper, a reliability framework is proposed, which combines event-driven simulation with mathematical model to analyze the reliability of proactive-tolerance Reed-Solomon storage systems. Monte Carlo simulation model simulates storage systems operation according to the failure parameters of different subsystems generated from statistical data. A mathematical model is designed to analyze the probability of data loss under certain concurrent failures. The proposed framework models the impact of various device failures (including permanent device failures, transient failures and correlated failures), network bandwidth, and both accurate predictions and false alarms of proactive fault tolerance on the reliability. The proposed reliability framework can be adapted to different Reed-Solomon codes and system configurations, offering versatility in its application and assist system designers in optimizing trade-offs and comparing schemes, which is beneficial for system design and operation.