What is NFS – Network File System (How it Works)

What is NFS – Network File System (How it Works). Network File System or NFS, as it is better known as is a file system distribution protocol that enables a user on a client computer to connect to a network and access files. It is similar to how you access files through local storage. Since Network File System is an open standard, anyone can execute the protocol. All people within a network have access to the same files, making the file sharing process easier.

A Network File System is a requisite for helping your business share files over a network. The NFS protocol was first introduced by Sun Microsystems in 1984 and had since been evolving. You can make adjustments to NFS as necessary.

What is NFS Server?

A basic system is used in NFS where a mount command will instruct the server to link with several clients. The clients will get access to the files on the server through the proper platform. The design can allow several security protocols to run in a place that will dictate who will have access to certain files, producing a safe and simplified approach to work.

NFS client server protocol begins with a “mount” command, a special client and server attributes option. The Network File System also has a file locking system in place that allows many clients to share the same file. The NFS can manage multiple computer threads and applications for operation. It uses multiple hosts that can access the same files. NFS does not require any application for its operation and provides a simple design for handling the content one will read.

Benefits of NFS Server (Pros)

  • The NFS server stands for central management.
  • Can be accessed from anywhere and enables multiple computers to use the same files.
  • Reduces storage costs by reducing the need for disk space.
  • The user to log into any server and have access to their files openly.
  • File system is transparent to all users that leads to data consistency and reliability.
  • Reduces administration costs.
  • For more security firewalls and Kerberos can be used.

Disadvantages of NFS Network File System (Cons)

  • File sharing can be highly complex.
  • Parallel file access is not commonly available yet, other than NFSv4.
  • Block size limitations which is a con of NFS and can be easily made larger, but then the timeouts would need to be adjusted too. 
  • Security: NFS is based on RPCs which are generally insecure. 
  • NFS  in generally can be vulnerable to internet threats.
  • It may be difficult for multiple parties to access a file simultaneously, especially if the file is more massive in size.
  • A firewall is necessary for running Network File System to keep unwanted parties from entering. 

The Three Versions of NFS. How do They Work?

The working of the Network File System varies based on the version of NFS you are using. There are three versions of NFS in use today, and each has a different standard of operation.

NFS Version II (NFSv2)

NFSv2 is the oldest version in use and is the most widely supported version. It operates with the UDP or User Datagram Protocol or through an IP network, allowing for a stable network connectivity.

The User Datagram Protocol on this setup does not formally produce a connection before it starts transferring data. The feature is convenient as it becomes easier for connections to work in less time. However, the UDP clients can keep sending requests for a server even when the server is not functional.

NFS Version III (NFSv3)

NFSv3 of the Network File System supports asynchronous writes, which allow the user to read out the correct policies for integrating data. The data will be integrated before a command to commit to managing the data is established. The design produces better buffering in comparison to NFSv2.

NFSv3 handles errors more effectively and can manage massive files. It can handle 64 bit files sizes. It means a user can access about 2GB of file size content at any point in time.

NFS Version IV (NFSv4)

NFSv4 is the most current version of the NFS protocol that is being used. It can work through firewalls and on the internet and It does not require a rpcbind service, making it simple to run in more places.

The TCP or Transmission Control Protocol runs in NFSv4 format. The TCP links between an IP and an application. It keeps a tab on the different data segments and only requires receiving the stray frames in the TCP set when data has to be sent for the second time.

The server also accepts port 2049 commands in TCP. This port is one of the more frequently used ports you will find on the market. It does not have to interact with daemons like the rpcbind and lockd options.

What All Services Are Essential to Make NFS File System Work

All Network File System versions rely on Remote Procedure Calls (RPC) between client and servers. You will need to have the following services work together for the Network File System to work. To make the NFS file system work, it is necessary to know which version of NFS has been implemented:

  • nfs – (/sbin/service nfs start) The nfs service will start the server and the RPC processes necessary for accepting shared systems
  • nfslock – (/sbin/service nfslock start)The nfslock service starts the RPC processes and allows NFC clients to lock files
  • portmap – With the help of portmap, you can take port reservations from local RPC services. portmap will respond to the messages stating that certain ports are available for file access. These ports are then made available so that the corresponding remote RPC services access them. portmap is not used with NFSv4

The Other Services for NFS setup

There are other services that you can program for facilitating an NFS setup:

  • rpc.mountd – You can begin with a procedure that collects mount requests and validates that a computer system can reach the NFS files one wishes to access. This process automatically starts with the help of the nfs service and does not require user configuration. rpc.mountd is not used with NFSv4.
  • rpc.nsfd – Here, you can define the explicit NFS versions and protocols for the server to support. It functions with the Linux kernel to accommodate the dynamic demands of Network File System clients, like providing server threads each time an NFS client connects. This process corresponds to the nfs service.
  • rpc.lockd – You can easily lock the files on the server with this command. If rpc.lockd is not stated, the locking of files will be a failure. rpc.lockd deploys the Network Lock Manager (NLM) protocol. It corresponds with the nfslock service. This command is not used with NFSv4.
  • rpc.statd – The Network Status Monitor (NSM) protocol will start with this command. It will notify the clients when a server restarts, plus it ensures the server stays online without the possibility of being shut down. This procedure is started automatically by the nfslock service and does not require user configuration. This service is not used with NFSv4.
  • rpc.rquotad – This process helps in providing user quota data for remote computer users. This process starts automatically with the nfs service and does not require user configuration.
  • rpc.idmapd – This process provides NFSv4 clients and server upcalls with that map between NFSv4 names (these are strings in the form of user@domain) and local GIDs and UIDs. For idmapd to work with NFSv4, the /etc/idmapd.conf must be laid out accordingly. This service is required for NFSv4 to be functional.

What Makes The Network File System Useful?

There are many positives surrounding the Network File System to explore:

  • Everyone in your network can have access to the same files when they become clients of the same Network File System
  • The mounting procedure for the file system remains transparent, giving clients an idea of how they can handle the content you manage
  • The NFS is possibly more secured as you won’t be having that many removable disks and drives to handle
  • Multiple computers can use the same set of applications. They won’t have to use excess disk space, and they would not have to store things as often

What is NFS – Network File System (How it Works) Conclusion

The Network File System may be necessary when you are trying to get files out to more people in your network. Be sure of how the NFS works if you are making your network and your file contents visible to everyone in your business.

Avatar for Hitesh Jethva
Hitesh Jethva

I am a fan of open source technology and have more than 10 years of experience working with Linux and Open Source technologies. I am one of the Linux technical writers for Cloud Infrastructure Services.

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