System support for providing integrated services from networked multimedia storage servers

Abstract

In this paper, we describe our experience in building an integrated multimedia storage system, Prism. Our current Linux-based implementation of Prism provides three levels of service: deadline guarantees for periodic applications, best-effort better response times for interactive applications and starvation-free throughput guarantees for aperiodic applications. Prism separates resource allocation from resource scheduling. Resource allocation is controlled across the service classes by a system-wide policy and service class specific admission controllers. Resource scheduling is done at the resources. This separation allows Prism to be deployed even when the storage system is separated on a network from the file system.We report on the important aspects of Prism architecture, innovations required to build Prism on top of Linux and lessons learned during the implementation and testing of Prism. We present experimental results to show that Prism achieves its goals in supporting multiple service classes within a single system. We compare Prism against standard Linux operating system to show the impact of our approach.