Product : Oracle, Oracle VM/3.4, x86 Edition
Feature : Max Disk Size, Storage, Network and Storage
Content Owner:  Roman Macek
Summary
10 TB (if Virtual Disk on OCFS2), Maximum supported on the Guest OS/Filesystem (if Raw Disks)
Details
For NFS there is no limit specified since it depends on the Backend Local Filesystem of the NFS Server. More info on: http://docs.oracle.com/cd/E64076_01/