NFS version 4 Protocol

The Network File System (NFS) Version 4 is a new distributed file system similar to previous versions of NFS in its straightforward design, simplified error recovery, and independence of transport protocols and operating systems for file access in a heterogeneous network. Unlike earlier versions of NFS, the new protocol integrates file locking, strong security, operation coalescing, and delegation capabilities to enhance client performance for narrow data sharing applications on high-bandwidth networks. Locking and delegation make NFS stateful, but simplicity of design is retained through well-defined recovery semantics in the face of client and server failures and network partitions. This paper describes the new features of the protocol, focusing on the security enhancements, integrated locking support, changes to fully support Windows file sharing semantics, support for high performance data sharing, and the design points that enhance performance on the Internet. We describe applications of NFS Version 4. Finally, we describe areas for future work.