Re: [PATCH v11 00/20] nfs/nfsd: add support for localio

Christoph Hellwig
2024-07-06T06:02:18Z

On Sat, Jul 06, 2024 at 08:08:07AM +1000, NeilBrown wrote:
> I would like to see a good explanation for why NOT NFSv3.
> I don't think NFSv3 is obsolete. The first dictionary is "No longer in
> use." which certainly doesn't apply.
> I think "deprecated" is a more relevant term. I believe that NFSv2 has
> been deprecated. I believe that NFSv4.0 should be deprecated. But I
> don't see any reason to consider NFSv3 to be deprecated.

The obvious answer is that NFSv4.1/2 (which is really the same thing)
is the only version of NFS under development and open for new features
at the protocol level. So from the standardization perspective NFSv3
is obsolete.

But the more important point is that NFSv4 has a built-in way to bypass
the server for I/O namely pNFS. And bypassing the server by directly
going to a local file system is the text book example for what pNFS
does. So we'll need a really good argument why we need to reinvented
a different scheme for bypassing the server for I/O. Maybe there is
a really good killer argument for doing that, but it needs to be clearly
stated and defended instead of assumed.