Features/NFSv4Default

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Contents

NFSv4Default

Summary

Changed the default NFS protocol to version 4.

Owner

  • email: steved@redhat.com

Current status

  • Targeted release: Fedora 12
  • Last updated: July 15, 2009
  • Percentage of completion: 30%


Detailed Description

The latest version of the NFS protocol is version 4, which was first introduced in Fedora F-2 (the first distro to have such support). The current default NFS version is version 3. Meaning when an simple NFS mount is done (i.e. mount server:/export /mnt) version 3 is the first protocol version that is tried.

With the proposed changes, version 4 would be tried first. If the server does not support version 4, the mount would then try version 3.

Benefit to Fedora

One of the major benefit is performance. In version 4, the server now has state which means it can communicate with each NFS client. The means the server can issue things called delegations (or leases) for files allowing the v4 client to aggressively cache which drastically cuts down on network traffic between the client and server.

There a number of other benefits which are documented in the following link:

     http://www.iaps.com/NFSv4-new-features.html

Scope

There are basically three parts to make this happen: 1) Change the exports on the server so v3 and v2 exports

  can *seamlessly* be used by v4 clients. 

2) Change the mount command to start negotiating with the

  version 4 protocol and then fall back to version 3 if
  the server does not support v4 (similar to what happens
  today with version 3 and version 4)

3) Introduce a NFS mount configuration file where users

  can define which protocol version should be negotiated.

How To Test

The usual Connectathon tests will be used and well as anyother filesystem tests that are available (such as fsx).

User Experience

This transition should be seamless to the users...

Dependencies

The only dependency is on the nfs-utils package.

Contingency Plan

If the code is not ready, then the version 3 will still be the default.


Documentation

http://www.nfsv4.org/

Release Notes

  • Fedora now use NFS version 4 as the default protocol version.

Comments and Discussion