NFS stands for Network File System, through NFS a client can access (read & write) directory shared by the NFS server. Its a distributed system protocol originally designed by SUN Microsystem. The shared storage act as a local storage for the client.
The post will guide to configure NFS server & client on CENTOS 6.2.  Here we consider a scenario of two linux machine.

Machine 1-: NFS-server: IP address-> 10.10.10.1
Machine 2-: NFS-client: IP address-> 10.10.10.2

Configuration For  NFS-server

Step-1 Download the NFS package on server
# yum install nfs-utils nfs-utils-lib
# service nfs start

Step-2 Exporting the directory to share on server
I will make a directory /var/nfs  to be shared with the client machine,for this we have to export the directory.
When a client access a NFS share, its normally happens as the user nobody. So create a directory /var/nfs and change its permissions. Make owner of directory to user nobody user id as 65534

#mkdir /var/nfs
#chown 65534:65534 /var/nfs
#chmod 777 /var/nfs

edit in the /etc/exports directory to export our NFS share.
# vim /etc/exports
/var/nfs                                10.10.10.2(rw,sync,no_subtree_check)

save and quit the file.

Whenever we modify /etc/exports. must run
# exportfs -a

This end the server side configuration for NFS.

Configuration For  NFS-Client 

Step 1. Download the NFS package
# yum install nfs-utils nfs-utils-lib
Create the directory to Mount for NFS share
# mkdir -p /mnt/nfs
Step 2. Mounting the shared directories
# mount 10.10.10.1:/var/nfs   /mnt/nfs
mount take 2 parameters, first is NFS server IP and  directory which is exported and second is the NFS client directory to mount.

To check the mounted directory run command
# df -h
Filesystem      Size      Used     Avail     Use%    Mounted on
/dev/sda6        56G      6.5G     47G      13%        /
10.10.10.1:/var/nfs  30G 20G   10G     66.66%  /mnt/nfs

This create the temporary mount point for NFS shared. To make boot time mount point make entries in /etc/fstab. Open the file using vim editor and make the following entries at bottom of file with NFS specification.

# vim /etc/fstab
10.10.10.1:/var/nfs     /mnt/nsf     nfs   rw,sync,hard,intr 0 0

It contains server name:path    /mountpoint     fstype  option, option…..

Testing the configure NFS

Step 1. Create empty file on NFS client share directory 
# touch /mnt/nfs/test.txt
Step 2. Check the files on the server
# cd /var/nfs
# ls
# test.txt

NFS configuration is completed.