NFS: Part I, The Protocol

Ron McCarty
October 2001

The Network File Server (NFS) protocol provides an open standard for giving clients remote access to file systems. NFS allows administrators to create centralized file systems that ease management tasks such as backups and virus checking. Large, centralized drivers are easier to maintain than many distributed small drives.

Besides lending itself to centralized storage, NFS has also proven itself useful in other applications such as diskless and thin clients, network clustering, and cross-platform interoperability applications.

A better understanding of the protocol and implementation considerations will ensure smooth operations of remote file access via NFS. This two-part article covers NFS -- the first part covers the protocol and design considerations, and the second part covers using NFS on Solaris and Linux.

In the Beginning...

The NFS protocol was originally designed by Sun and eventually released to the Internet with RFC 1094, "NFS: Network File System Protocol Specification" in 1989. It is interesting to note that Novell's strategy at the time was to perfect file services in a very closed manner, and although Sun had not, until the recent open source movement, been as open on network implementations, they did see the importance of interoperability with other systems.

RFC 1094 covered the original two specifications, but Version 3 was already under specification development as Sun released the original RFC. Version 3's specification is covered in RFC 1813, "NFS Version 3 Protocol Specification". Version 4 of the protocol is defined in RFC 3010, "NFS Version 4 Protocol".

NFS is widely deployed on all types of UNIX hosts, Microsoft and Novell networks, and IBM solutions such as AS400 and OS/390. Despite its not being known outside the network realm, it may be the most widely deployed platform-independent network file system.<>