Comparison between NFS V3 and various versions

As we all know about the NFS protocol, as the network continues to send emails, there are already many versions available. Today, we will mainly explain the basic knowledge of NFS and some comparisons between their versions, including NFS V2rfc1094) and NFS V3rfc1813) NFS V4.

I. Introduction to NFS

NFS-Network FileSystem, developed by Sun, is used to share files between different machines and operating systems over the Network. NFS server can also be seen as a file server, which allows your PC to MOUNT the files shared by the remote nfs server to its own system through the network, in the CLIENT's view, the remote file using NFS is like a local file.

The NFS protocol has been available in multiple versions since its birth, such as NFS V2rfc1094) and NFS V3rfc1813) the latest version is V4rfc3010 ).

Ii. Main differences between NFS Protocol versions

Major differences between V3 and V2:

1. File Size

V2 supports up to 32-bit file sizes (4 GB), while NFS V3 supports 64-bit file sizes.

2. File Transfer size

V3 does not have a limited transmission size. V2 can only be set to 8 KB at most. You can use-rsize and-wsize to set it.

3. complete information is returned

V3 has added and improved the return of many errors and successful information, which brings great benefits to server settings and management.

4. Added support for TCP transmission protocol

V2 only provides support for the UDP protocol, which has great limitations in some demanding network environments. V3 has added support for the TCP protocol.

* 5. asynchronous writing

6. Improved SERVER mount Performance

7. Better I/O WRITES performance.

9. Enhanced network operation efficiency, making network operation more effective.

10. Better disaster recovery functions.

Introduction to asynchronous write feature v3:

Whether NFS V3 can be written asynchronously is an optional feature. the NFS V3 client sends an asynchronous write request to the server. before replying to the client, the server does not have to write data to the memory stably ). the server can determine when to write data or aggregate and process multiple write requests, and then write data. the client can maintain a copy of the data, in case the server cannot completely write the data. when the client wants to release this copy, it will pass this operation process to the server to ensure that each operation step is complete. asynchronous writing allows the server to determine the best data synchronization policy. how can data be submitted synchronously as much as possible. compared with V2, this mechanism can better achieve data buffering and more parallel balances ). the NFS V2 SERVER cannot write data to the memory before writing data.

V4 compared with V3:

1: improved access and execution efficiency on the INTERNET

2: enhanced security features in protocols

3: enhanced cross-platform features