Scale and Performance in a Distributed File System

J.H. Howard, M.L. Kazar, S.G. Menees, D.A. Nichols, M. Satyanarayanan, R.N. Sidebotham, M.J. West


The Andrew File System is a location-transparent distributed file system that will eventually span more than 5000 workstations at Carnegie Mellon University. Large scale affects performance and complicates system operation. In this paper we present observations of a prototype implementation, motivate changes in the areas of cache validation, server process structure, name translation and low-level storage representation, and quantitatively demonstrate Andrew's ability to scale gracefully. We establish the importance of whole-file transfer and caching in Andrew by comparing its performance with that of Sun Microsystem's NFS file system. We also show how the aggregation of files into volumes improves the operability of the system.