[Samba] Samba CTDB with data coming via pNFS?

[JRS]

Greetings all,

Does anyone know whether I'll encounter problems serving out CIFS using
Samba/CTDB where the servers are pNFS clients? 

In more detail:
The servers are linux virtual machines running RHEL 6.2.  They mount
volumes coming from the latest net app OS (which runs a pNFS service). 
I'll then put samba and CTDB on of these machines to serve data to our
windows clients.  Samba will authenticate to a windows AD.  I'm not yet
sure how the authentication/acls will work.

I've run a similar configuration using GPFS as the backend filesystem
(fast for sequentail IO but challenged with metadata performance).  Will
locking be an issue?

Thanks for any insight,
JR