A low-bandwidth network file system

TLDR

Network file systems are rarely used over slow or wide‑area links because of poor performance and high bandwidth usage, yet remote file access is often needed when high latency makes interactive sessions unresponsive. This paper introduces LBFS, a network file system engineered to operate efficiently on low‑bandwidth networks. LBFS reduces traffic by exploiting similarities between files or file versions, sending data only when it is not already present on the server or in the client’s cache. In practice, LBFS combined with standard compression and caching achieves more than an order of magnitude lower bandwidth consumption than conventional network file systems on typical workloads.

Abstract

Users rarely consider running network file systems over slow or wide-area networks, as the performance would be unacceptable and the bandwidth consumption too high. Nonetheless, efficient remote file access would often be desirable over such networks---particularly when high latency makes remote login sessions unresponsive. Rather than run interactive programs such as editors remotely, users could run the programs locally and manipulate remote files through the file system. To do so, however, would require a network file system that consumes less bandwidth than most current file systems.This paper presents LBFS, a network file system designed for low-bandwidth networks. LBFS exploits similarities between files or versions of the same file to save bandwidth. It avoids sending data over the network when the same data can already be found in the server's file system or the client's cache. Using this technique in conjunction with conventional compression and caching, LBFS consumes over an order of magnitude less bandwidth than traditional network file systems on common workloads.