A Distributed Rate-Adapting Buffer Cache for Mass Storage Systems

To address mass storage needs common to both DESY and Fermilab, a rate-adapting buffer cache is under development. The aim is to maximize utilization of limited tiary storage resources by the use of prefetching (read-ahead) and caching of files based on access statistics, as well as decoupling network transfer rate from tape I/O rate. A modular architecture allows cache capacity to be dynamically reconfigured by adding or removing ”cache pools”, as well as allowing the system to work with several different mass storage systems. PNFS is used to provide the underlying namespace and to store cache-related metadata