Efficient Memory Management in VOD Disk Array Servers Using Per-Storage-Device Buffering

In this paper we present a new buffering technique that reduces Video-On- Demand server memo y requirements in more than one order of magnitude. This technique, Per-Storage-Device Buffering (PSDB), is based on the allocation of a,fixed number of buffers per storage device, as opposed to existing solutions based on per-stream bufering allocation. The combination of this technique with disk array servers is studied in detail, as well as the injuence of ' Variable Bit Streams. We also present an interleaved data placement strategy, Constant Time Length Declustering, that results in optimal performance in the sewice of VBR streams. PSDB is evaluated by extensive simulation of a dish- array server model that incorporates a simulation-based admission test