Re NFS & file sharing:
If you have UNIX/Linux clients then you use NFS, if you have Windows clients then you use CIFS - in 99% cases this is as simple as this.
Just type "NFS Oracle" in a search window in the top right-hand corner & you'll see what already has been posted here - a lot!
(e.g. this: http://communities.netapp.com/message/2018#2018)