Published in the Ninth International Symposium on Modeling, Analysis and Simulation of Computer and Telecommunication Systems (MASCOTS-2001), August 15-18, 2001, Cincinnati, Ohio, USA A Modular, Analytical Throughput Model for Modern Disk Arrays

Enterprise storage systems depend on disk arrays for their capacity and availability needs. To design and main- tain storage systems that efficiently satisfy evolving require- ments, it is critical to be able to evaluate configuration alternatives without having to physically implement them. In this paper, we describe an analytical model to predict disk array throughput, based on a hierarchical decompo- sition of the internal array architecture. We validate the model against a state-of-the-art disk array for a variety of synthetic workloads and array configurations. To our knowledge, no previously published analytical model has either incorporated the combined effects of the complex op- timizations present in modern disk arrays, or been validated against a real, commercial array. Our results are quite en- couraging for an analytical model: predictions are accu- rate in most cases within 32% of the observed array per- formance (15% on the average) for our set of experiments.