Capacity planning with phased workloads
Elizabeth Borowsky, Richard A. Golding, Peter Jacobson, Arif Merchant, Louis C. Schreier, Mirjana Spasojevic, John Wilkes · 1998
At the heart of any configuration or capacity planning algorithm for storage systems, there lies a "what if" question: given a device and a set of workloads accessing data on the device, will the quality of service requirement for each workload be satisfied? This is, in general, a hard question to answer because of the complexity of workloads in real life. In this paper, we consider QoS bounds on the 95th percentile of response time and demonstrate an approximate method to verify that the QoS requirement is satisfied for a complex and fairly general set of workloads, including workloads with phasing (on/off behavior) and correlations with other workloads. 1 Introduction The Forum project [1] addresses the problem of capacity planning and automatic configuration of storage devices to meet QOS requirements of applications. In its simplest form configuration may be thought of as a data layout problem: how to allocate (lay out) storage to a given set of applications on a given set of devi...