question on setting up VLAN between two Fortinets

[jamestiberius]

here is our setup. site #1 has a Fortinet 600C. site #2 has Fortinet 90D. the two sites are connected via IPSEC tunnel. we want to replicate our virtual machines from site #1 to site #2. so the plan is at site #1 to have network cable going from our SAN to port #9 on the fortinet 600C. and then at site #2 a network cable from port #9 on the forintet 90d to the san at that site. can we do vlan\trunk from port 9 on 600c, across IPSEC vpn tunnel, to port 9 on the 90d, so we can replicate the traffic?

I have not created any VLANs on the Fortinets themselves before, so not sure how to do this.