We have examined the procesos f staginddestaging of data with a view toward establishing certain performance characteristics of the MSS. The main issue we address is: What is the maximum throughput achievable on the MSS? The analysis is based on a simple queuing model, the validity of which has been established by comparing its predictions with the measurements gathered in our operational environment. The results have been found of value in monitoring and tuning MSS usage, in evaluating alternative design changes, and in workload planning.