Several older UNIX file system performance studies have shown that files are usually accessed sequentially [16,1]. A recent study [19] has suggested that this is changing, especially for memory-mapped and large files. However, UNIX file systems have been designed for the traditional sequential workload. Web proxies have an even stronger and more predictable pattern of behavior. Web proxies currently always access files sequentially and in their entirety. (This may change when range requests are more popular.)