Accessing storage resources over wide-area networks is enabled by recent standards such as iSCSI and FCIP which allow storage traffic to be transmitted over IP networks. Wide-area storage access is required when storage systems are hosted remotely by a storage service provider, where customer applications are remote from the data center. Wide area networks, however, are usually characterized by high latencies and low bandwidths compared to storage-area networks. While investments in networking infrastructure combined with greater bandwidth demand may result in cost-effective bandwidths over the wide area, the relatively higher latencies of wide area communication is a problem that is likely to persist for the fore-seeable future. This article investigates the viability of wide-area distance-connected storage for various application classes. Based on preliminary analysis of application workload characteristics (e.g., access patterns), we categorize key commercial applications with respect to how well they might perform in a re-mote storage service architecture. Secondly, we describe a customer-side storage caching appliance that alleviates the latency and bandwidth problems of wide-area storage services, and estimate its expected performance benefits using a simple analytical model.
By: Khalil S. Amiri, Seraphin B. Calo, Kang-Won Lee
Published in: RC22278 in 2001
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