Re: Status of delegations feature in NFSv4 client

> >> I wanted to understand if the file delegations feature on the NFSv4
> >> client is stable enough on Linux to support it in production
> >> environments? It looks like this feature has been around on the client
> >> or a really long time now. We tried running some workloads and file
> >> delegations offer really good perf benefits.
> >
> >Like you've said above, file delegations have been around for a long time
> > and I would expect them to be stable for production environments.
>
>If there is a problem in NFS, we will see it. Rare events occur several times a semester. Impossible events occur at least once a year.
>
>The worst case for delegations is heavy use of vscode with an NFS home directory. This will hang an Ubuntu 24.04 client, kernel 6.8. We have been successful with Ubuntu 24.04 >upgraded to kernel 6.17, and a Redhat 9.8 server. I assume a Redhat 9.8 client would also be OK, since they backport things.
>
>Our kernels have file delegation but not directory delegation, so I can't comment on the latter.

Ugh. The upgrade to 6.17 failed. TEST_STATEID loops on some clients. Next try: 7.0 when the Ubuntu 7.0 HWE comes out in August. there are known causes of this problem that look like they have been fixed in 7.0 but not 6.17. And it looks like Ubuntu didn't backport.

I'm not sure where the right place for this is, but it would be useful for sites like mine to know what it's safe to use in what release. So far NFS 4.2 looks OK for Ubuntu's 6.8 and 6.17 except for a very odd problem due to network interruption. But with delegations off.