Alternate File Sharing Systems

NFS is not the only file sharing system under Unix to share files on a network, but it is the most common. Alternatives to NFS include AFS, DFS and RFS.

AFS - Andrew File System

AFS is a distributed file system that enables co-operating hosts (clients and servers) to efficiently share file system resources across both local area and wide area networks. It is based on a distributed file system originally developed at the Information Technology Center at Carnegie-Mellon University that was called the "Andrew File System". It is marketed, maintained, and extended by Transarc Corporation.

Although not as popular as NFS, AFS does have a strong support within some universities. AFS scales better than NFS. It performs well in small and very large installations, provides excellent performance on wide-area configuration and security based on kerberos mutual authentication.

For additional optional information please refer to the following items.
AFS User's Guide
Comparison of AFS to NFS?
AFS in Distributed Computing Environment

DFS - Distributed File System

DFS is another remote file system protocol that supports large files. It grew out of the OSF's DCE project. For optional reading see the Quick DFS Tutorial.

RFS - Remote File Sharing

RFS is a distributed file system provided with most SVR5 releases. It is also supported by more recent versions of SunOS. The main features of RFS are:

Unlike NFS which provides a generic file system, RFS provides an exact copy of a Unix file system.
RFS provides access to files and directories without the user having to know where the resource is located. A name-server is used to register resource names, so the client machines doesn't need to know where the resources are.
RFS allows users to mount special directories so that they can share devices (e.g. tape drives) residing on other machines.
RFS is a stateful protocol; the server maintains state information of local resources. The server can detect client crashes, so that cache consistency is guaranteed.
For the most part, security threats associated with NFS are also associated with RFS.

For further information see the optional reference on RFS