Cost/performance study of video servers with hierarchical storage

A cost/performance analysis of a video server with hierarchical storage is presented. Three different storage elements are considered for the video files, namely, RAM (Main memory or Expanded Storage), DASD (Direct Access Storage Device) and Tape Library. Each storage element has different cost, storage and bandwidth characteristics. Video files are assumed to have a certain demand and a duration distribution which are defined by the customer profile. A high level model is developed to size the storage requirements and to allocate the video files to different storage elements.