Measured performance of caching in the Sprite network file system

This paper reports on the effectiveness of the caching strategy used in the Sprite network file system based on data taken over several weeks of day-to-day usage by a variety of users. Measurements include cache consistency activity, long term I/O traffic rates, long term cache hit rates, and the averages and variations in the size of the variable-sized caches. Network traffic is compared with traffic to the local cache, and the effects of paging traffic are con-sidered. The overall conclusion is that the caching system is quite effective and poses a low overhead. Using a delayed write strategy, 40 % to 50 % of the data written to client caches is never written through to a server, and less than 1 % of the open operations by clients resulted in cache consistency actions by a server.