5.4.2. Beware of Syntax Errors

The NFS server determines which file systems to export and which hosts to export these directories to via the /etc/exports file. Be careful not to add extraneous spaces when editing this file.
For instance, the following line in the /etc/exports file shares the directory /tmp/nfs/ to the host bob.example.com with read/write permissions.
 /tmp/nfs/ bob.example.com(rw) 
This line in the /etc/exports file, on the other hand, shares the same directory to the host bob.example.com with read-only permissions and shares it to the world with read/write permissions due to a single space character after the hostname.
 /tmp/nfs/ bob.example.com (rw) 
It is good practice to check any configured NFS shares by using the showmount command to verify what is being shared:
 showmount -e <hostname>