NFSv4 server running on RHEL 5.2 -- Server/Client Incompatibilities?

[Paarvai Naai]

Hi Bruce,

> The two may be unrelated--this will fail anyway because BSD flock locks
> aren't really supported over nfsv4.  (Well, it's more complicated than
> that: actually the client does attempt to support flock() by translating
> its locks into posix locks, but exclusive posix locks aren't permitted
> on files open for read, whereas BSD locks are.  And the flock utility
> just does a read open.  You won't get this error on v3 since v3 doesn't
> have on-the-wire opens....)

Ah, that's a subtle difference that I did not realize.  Thank you for
the explanation.

> If this worked before it may just be because the old client didn't
> actually try to do the flock->posix lock translation, hence just
> performed the flock locally?

I was using NFSv3 before but was recently exploring NFSv4 because
locking doesn't work well when using NFSv3+KRB5.


> The NFSv4.0 protocol hasn't been changed for several years, so any
> incompatibilities between different versions are implementation bugs.

Great.  That's good to know.


>> Lastly, the following pages seem to be a bit out-of-date.  Are there
>> new pages that list the current status/stability of the NFSv4 support
>> for Linux?
>
> No.  Unfortunately it seems hard to keep a good up-to-date description.

Yes, I guess that's true.  I did find some more recent information on
the following pages:

http://wiki.linux-nfs.org/wiki/index.php/Main_Page
http://nfsv4.bullopensource.org/

The latter gives some decent reports of stability and such.  If there
are any other pages that are worth looking at to build confidence in
the completeness/stability of NFSv4, please do let me know.


BTW, what happened to this feature for "key ring" support that was
talked about a few years back?  I remember it was mentioned as a
possible solution to the kdestroy issue.  The following did catch my
eye from combing the past couple months of mailing list postings:

http://linux-nfs.org/pipermail/nfsv4/2008-June/008860.html

Thanks again,
Paarvai