Network administrations

NFS, or Network File System, is a server-client protocol for sharing files between computers on a common network. NFS enables you to mount a file system on a remote computer as if it were local to your own system. You can then directly access any of the files on that remote file system. The server and client do not have to use the same operating system. The client system just needs to be running an NFS client compatible with the NFS server.

Dear visitor this article is written for RHEL 5. We have updated version of this article for RHEL6. If you are looking for RHEL6 please check this article. How to configure NFS Server in RHEL6.

For example NFS server could be a Linux system and Unix could be a client. But it can’t be a window system because window is not NFS compatible. The NFS server exports one or more directories to the client systems, and the client systems mount one or more of the shared directories to local directories called mount points. After the share is mounted, all I/O operations are written back to the server, and all clients notice the change as if it occurred on the local filesystem.

A manual refresh is not needed because the client accesses the remote filesystem as if it were local.because access is granted by IP address, a username and password are not required. However, there are security risks to consider because the NFS server knows nothing about the users on the client system.

Exam question 1 Some users home directory is shared from your system. Using showmount -e localhost command, the shared directory is not shown. Make access the shared users home directory

Exam question 2 The System you are using is for NFS (Network File Services). Some important data are shared from your system. Make automatically start the nfs and portmap services at boot time

Exam question 3 Share /data directory using NFS only to 192.168.0.0/24 members. These hosts should get read and write access on shared directory.

Configure nfs server

In this example we will configure a nfs server and will mount shared directory from client side.

For this example we are using two systems one linux server one linux clients . To complete these per quest of nfs server Follow this link

Network configuration in Linux

  • A linux server with ip address 192.168.0.254 and hostname Server
  • A linux client with ip address 192.168.0.1 and hostname Client1
  • Updated /etc/hosts file on both linux system
  • Running portmap and xinetd services
  • Firewall should be off on server
We suggest you to review that article before start configuration of nfs server. Once you have completed the necessary steps follow this guide.

Three rpm are required to configure nfs server. nfs, portmap, xinetd check them if not found then install
rpm

Now check nfs, portmap, xinetd service in system service it should be on

#setup
Select  System service
from list
[*]portmap [*]xinetd [*]nfs

Now restart xinetd and portmap service
service restart
To keep on these services after reboot on then via chkconfig command
chkconfig
After reboot verify their status. It must be in running condition
service status

now create a /data directory and grant full permission to it
mkdir

now open /etc/exports file
vi exports
share data folder for the network of 192.168.0.254/24 with read and write access
editing in exports
save file with :wq and exit

now restart the nfs service and also on it with chkconfig
service nfs restart
also restart nfs daemons with expotfs
exportfs

verify with showmount command that you have successfully shared data folder
showmount

configure client system

ping form nfs server and check the share folder
showmount

now mount this share folder on mnt mount point. To test this share folder change directory to mnt and create a test file
mount server directory

After use you should always unmount from mnt mount point
unmount

In this way you can use shared folder. But this share folder will be available till system is up. It will not be available after reboot. To keep it available after reboot make its entry in fstab

create a mount point, by making a directory
mkdir

now open /etc/fstab file
vi fstab
make entry for nfs shared directory and define /temp to mount point

file fstab

save the with :wq and exit reboot the system with reboot -f command

 #reboot -f 

after reboot check /temp directory it should show all the shared data
cd temp