Hierarchical storage servers for video on demand: feasibility, design and sizing

We study the problem of designing a hierarchical storage server to support a given rate of video requests within specified quality of service requirements. We ask what combinations of disk storage, disk bandwidth and tertiary storage and bandwidth are required to support given request rates for videos, and how these resources should be configured to minimize cost. We show a basic design, and a series of refinements that provide the required performance at a lower cost