We will be exposing one of the directories originally created on NFS network drive – in my case it was called Multimedia.

Login with to your QNAP drive as root. This is the machine working as a host.
Edit /etc/exports file. It should contain the following content:

"/share/Multimedia" *(rw,async,no_subtree_check,insecure,no_root_squash) 

Run the following command:

exportfs -ra

It should recreate the exported file systems according to /etc/exports file.

Now, login to your Linux machine and run the following commands:
The following step might be not necessary:

sudo apt-get install portmap nfs-common

Create the mounting point directory:

mdkir -p /media/qnap

And finally mount the NFS directory:

sudo mount [ip_of_the_qnap_server]:/share/CACHEDEV1_DATA/Multimedia /media/qnap