This is a configuration issue. A required parameter needs to be added to the file /etc/exports to define the root file system for mounting.
The parameter that needs to be added follows:
fsid=0
An example line would look like the following:
/storage *(rw,fsid=0,sync,insecure_locks,insecure,no_root_squash)
Additional information
NFSv4 works differently and no longer references the root of the file system but instead requires the root to be defined with fsid=0.
If fsid=0 is not present, permission will never be granted for the file system to be mounted.
NFS4 is different. After configuring exportfs the old fashioned way the nfs mounts did not work at all. I narrowed it down to the CentOS server running nfs4 and then found this article from IBM. It seems to work now.