Seems like the steps on how to get the NFS mount point from the D-Link DNS 320L NAS server were not properly documented in their user manual.
After setting up and enabled the NFS service on the D-Link DNS 320L NAS server, I went ahead to setup and mount the share directory/folder in Ubuntu 12.04 LTS assuming the mount point in NAS was /Volume_1/... but that is not the correct mount point to start with!
Found this answer from D-Link forum post from a member (ba43123) that helped me to correctly mount the NFS share directory/folder on Ubuntu 12.04 LTS:
After spending most of the last hour on the phone with D-Link Technical Support, I came away with the recommendation to take my Mac (which has successfully connected to a number of NFS shares in the past) to Apple to determine if the network settings for NFS are correct. This is mostly due to the fact that the people who are taking the calls have no information about NFS in their scripts and Knowledge Base so they are at a total loss in trying to provide any assistance.
The correct solution is as follows: Under Account Management > Network Shares, when you set up the share for NFS access a little icon appears in the Network Shares Settings table in the NFS column in the row for that share. Although it does not appear to be a link, clicking the icon brings up a pop-up window with the settings for that share. The critical item here is the string labelled "Real Path"; this is the string that needs to follow the host name.
As an example, if your DNS-325 has a host name of "nas" and you are sharing "Volume_1/nfs". The correct string (at least on my box) to mount the share on Linux is "nas:/mnt/HD/HD_a2/nfs" and on the Mac is "nfs://nas/mnt/HD/HD_a2/nfs". I suspect the "/mnt/HD/HD_a2/" part is dependent on how the disks are configured so be sure to look up the correct string for the share on your own DNS-325.
References, Sources and Credits:
- D-Link Forums -> D-Link ShareCenter Network Storage -> DNS-325 -> Problems With NFS