I try to connect a TrueNAS (scale) VM to a TrueNAS dataset via NFS4. I managed to do that, however NOT with the intended security setup.
My intention is to define a dataset owned by the VM for which the dataset is intended like this:
- owner ^Mister-VM^ all permissions
- group ^Mister-VM^ not relevant / all permissions
- others no permissions at all
So apart from root and ^Mister-VM^, not a single user has access to the dataset.
On the VM the intended setup is:
- the dataset is mounted at start
- permanently mounted not timeouts etc
- accessible for a certain user group NOT having root permissions
- one or more services are running as user-x,y,z.
- those user(s) is member of the group having full NFS-share permissions
I have no idea how to do this !! 
Of course If I run the service as root and /or I change the TrueNAS dataset permissions to “allow all for others” there it works!! But that is IMHO absolutely a bad idea !!
I hope someone knows how to get this done.
See my earlier post ^Setup TrueNAS VM having NFS-share via storage VLAN. Two issues!^ describing how to setup NFS4 (with permissions like I do NOT want them!!)