Best/suggested way to connect two TrueNAS systems

[pixel8383]

Hello, I have to connect each other two TrueNAS systems in order to setup a bidirectional backup. The two system are located on different sites so I will have to setup a VPN on them in order to talk each other.

My first idea was to create a jail with OpenVPN but this way the only visible files would be those dataset mounted to the jail. I think I would loose the ability to setup the Replication feature embedded on the system (and I should rely on rsync, duplicity and so on). So I was going to think to enable the OpenVPN server on one TrueNAS. This way I guess I would be able to reach one side but I am not sure the server would be able to communicate with the client subnet: OpenVPN will push the route to the client but not to itself. Is there any way to tell the NAS to use that network to communicate with the remote subnet?

The last strategy would be to setup two OpenVPN server (on both side). I guess this should work but I am not a great fan. Is this the solution? Do you have anything better to suggest?

I have no way to setup the VPN link externally to the TrueNAS systems unfortunately.