NFS: Network File System

From DrugPedia: A Wikipedia for Drug discovery

Network File System (NFS), originally developed by Sun Microsystems and then extended by IETF, allows file sharing over network among different types of systems. In other words, NFS was designed for remote file access and sharing over network with various types of machines, operating systems, network architecture and transport protocols.

NFS uses a client/server architecture and consists of a client program and a server program. The server program makes file systems available for access by other machines via a process called exporting. NFS clients access shared file systems mounting them from an NFS server machine. NFS mount protocol is used to communicate between the server and the client for the file access and sharing. NFS mount protocol also allows the server to grant remote access privileges to a restricted set of clients via export control.

NFS Version 2, the first widely implemented version of NFS, originally operated entirely over UDP and was meant to keep the protocol stateless. Several vendors had extended NFSv2 to support TCP as transport. NFS Version 3 introduced support for using TCP as transport. Using TCP as transport made using NFS over a WAN more feasible .

Inheritated the good features of the previous versions, the current NFS Version 4 features the following improvements:

• Improved access and performance on the Internet. The protocol is designed to transit firewalls easily, perform well where latency is high and bandwidth is low, and scale to very large numbers of clients per server.

• Strong security with negotiation built into the protocol. The protocol builds on the work of the ONCRPC working group in supporting the Remote Procedure Call (RPC) RPCSEC_GSS protocol. Additionally, the NFS version 4 provides a mechanism to allow clients and servers to negotiate security and require clients and servers to support a minimal set of security schemes.

• Designed for protocol extensions. The protocol is designed to accept standard extensions that do not compromise backward compatibility.

NFS is strongly associated with UNIX systems, though it can be used on any platform such as Macintosh and Microsoft Windows operating systems. The Server Message Block (SMB) and Common Internet File System (CIFS) are a similar protocol that have equivalent implementation of a network file system under Microsoft Windows.