nfsv41 mount semantics question

[Dean Hildebrand]

At our weekly linux pNFS meeting yesterday the issue of how to mount a
nfsv4.1 server arose.  We are looking for some clarification on how to
proceed with the implementation.

The first issue is with regards to whether we should use a new mount
type (e.g., '-t nfs41') or instead rely on the 'nfsvers' parameter
(e.g., '-t nfs nfsvers=4.1' or '-t nfs4 nfsvers=4.1').

It was pointed out that the long term goal is to remove the current
'nfs4' mount type and use only a single 'nfs' mount type and rely on the
'nfsvers' parameter to differentiate between versions.  Is this true?
(Note that the current nfs man page says the nfsvers parameter is not
supported for nfs4.)
If so, should we implement the nfsv41 code to use the mount type 'nfs'
and a nfsvers=4.1 (or 41)?

Another issue is if we move to using a single mount type of 'nfs', what
should the default value of 'nfsvers' be?  I'm assuming that for the
near term it would be 'nfsvers=3'.  Would it depend on what is compiled
into the kernel?

Anyways, we just want to get the conversation started at this point so
we can see what lies ahead.

In summary, a few sample options:
'-t nfs nfsvers=[2,3,4,4.1]'
or
'-t [nfs,nfs4] nfsvers=[2,3] (for nfs) or nfsvers=[4,4.1] (for nfs4)'
or
'-t [nfs,nfs4,nfs41] nfsvers=[2,3]' - nfsvers for nfs type only

Dean