nfs NULL procedure packets

nfs NULL procedure packets

[Russell Miller]

Hi again, I was hoping someone here could answer another question.  I
apologize if these are easy questions...

So a couple of days ago I was troubleshooting yet another NFS problem
(not the non-one I described a few days ago).  I sent a 1G file over
to a server, did a TCP capture, and analyzed the results.

I noticed a lot of NULL procedure packets.  A *lot* of them.  In some
cases, one every 10 microseconds, and there were about 400,000 of them
I captured.

This seems like a lot of network traffic for very little reason.

Is this normal behavior, or something I should investigate further?
It seems to me like pinging the NFS server once every 10 microseconds
is a major waste of bandwidth.

--Russell

Re: nfs NULL procedure packets

[J. Bruce Fields]

On Wed, Dec 03, 2008 at 10:11:26AM -0800, Russell Miller wrote:
> Hi again, I was hoping someone here could answer another question.  I
> apologize if these are easy questions...
> 
> So a couple of days ago I was troubleshooting yet another NFS problem
> (not the non-one I described a few days ago).  I sent a 1G file over
> to a server, did a TCP capture, and analyzed the results.
> 
> I noticed a lot of NULL procedure packets.  A *lot* of them.  In some
> cases, one every 10 microseconds, and there were about 400,000 of them
> I captured.
> 
> This seems like a lot of network traffic for very little reason.
> 
> Is this normal behavior, or something I should investigate further?
> It seems to me like pinging the NFS server once every 10 microseconds
> is a major waste of bandwidth.

It's either a bug, or you're misreading the traces--how are you
identifying these as NULL procedures?  Also, are they NULL NFS calls, or
some other rpc protocol?  And are you using krb5?

--b.