NFS Versions & Packages Required for NFS (LINUX/UNIX)

NFS: Network File System (NFS) protocol allow Linux client to mount remote file systems and interact with those file systems as they are mounted locally.

• NFS was developed by Sun Microsystems in 1980
• NFS stand for Network File System
• NFS is used to share files and printer between Linux / Unix systems
• Red Hat Enterprise Linux 6 supports NFSv2, NFSv3, and NFSv4 clients.
• By default RHEL6 use NFSv4 if the server supports it.
  

Packages required for NFS:

• nfs-utils - The nfs-utils package provides a daemon for the kernel NFS server and related tools, which provides a much higher level of performance than the traditional Linux NFS server used by most users.

• portmap - The portmap package should be installed on any machine which acts as a server for protocols using RPC.

• nfs4-acl-tools - This package contains command line and GUI & ACL utilities for the Linux NFSv4 client.
  

NFS Versions:

NFSv1:

1> NFSv1 was the development stage of NFS protocol.

2> It was used only for in house experimental purpose. 

NFSv2:

1> NFSv2 supports only 32 bit.

2> NFSv2 only allowed the first 2 GB of a file to be read

3> NFSv2 operated only over UDP

NFSv3:

1> NFSv3 supports 64 bit file system.

2> NFSv3 can handle files larger than 2 GB.

3> NFSv3 supports asynchronous writes on the server. asynchronous writes improve write performance.

4> NFSv3 supports additional file attributes in many replies, to avoid the need to re-fetch them.

5> NFSv3 supports READDIRPLUS operation. READDIRPLUS operation get file handles and attributes along with file names when scanning a directory.

6> NFSv3 supports TCP. Using TCP as a transport made NFS over a WAN more feasible.

NFSv4:

1> NFSv4 retains all NFSv3 advantages.

2> NFSv4 supports ACLs.

3> NFSv4 uses the virtual file system to present the server's export.

4> NFSv4 supports Pseudo file system. Pseudo File System provide maximum flexibility. 

5> Exports Pathname on servers can be changed transparently to clients.

6> NFSv4 have locking operations as the part of protocol which keep track of open files and delegations.

7> NFSv4 works through firewalls and on the Internet.