can one run an *exclusively* NFSv4 network?

[Tom H]

On Mon, Apr 18, 2011 at 5:30 PM, Robert P. J. Day <rpjday at crashcourse.ca> wrote:
> On Mon, 18 Apr 2011, Todd A. Jacobs wrote:
>> On Mon, Apr 18, 2011 at 2:21 PM, Robert P. J. Day <rpjday at crashcourse.ca> wrote:
>> >
>> >  i know i've asked this before but i've never had a really
>> > confident answer.  at least on ubuntu, is it possible to set up an
>> > NFS network that uses solely and exclusively version 4, with no
>> > support whatsoever for earlier versions?
>>
>> Do you mean excluding nfsv3 clients, or what? I'm not really sure
>> what you're trying to accomplish here.
>
>  precisely. when i've tried this before on other linux distros
> (explicitly deactivating earlier versions of NFS), i've had complaints
> that at least one earlier version of NFS *must* be active.  there
> didn't appear to be any reason for that.  so i just want to know if
> this is theoretically possible.

AFAIK, the situation hasn't changed since you last asked.

You can restrict access to an nfs server's shares to nfsv4 clients but
you have to have a pre-v4 version of mountd running on the server
because it's used locally by nfsd. You can firewall mountd off because
it doesn't need to be accessed remotely. lockd and statd don't need to
be running.