Re: FreeBSD 13.2 NFS client mount hangs

From: J David <j.david.lists_at_gmail.com>
Date: Mon, 09 Oct 2023 09:36:55 UTC
On Mon, Oct 9, 2023 at 1:34 AM Rick Macklem <rick.macklem@gmail.com> wrote:
> LocalOwn and LocalOpens indicate that the server did start issuing
> delegations.

Yes, with that enabled, the Delegs value from "nfsstat -Ec" climbs
into the low thousands. Performance does seem (gut feeling, not
tested) to be improved until the LocalOwns/LocalOpens pile up.

> All I can think of is that you have an environment where the
> same file(s) get open'd by multiple processes.

Yes.

> The "oneopenown" option at least ensures that there is a single
> open owner (without it, each process is a separate open owner).

I don't know what issue the "It may not work correctly when
Delegations are being issued by a server" warning about oneopenown
refers to.

Would that potential problem still be a concern if the only filesystem
mounted with oneopenown were also mounted readonly and with nolockd?
(Specifically: ro,nfsv4,minorversion=2,tcp,nosuid,noatime,nolockd,oneopenown)

Thanks!