To me you have the file server doing too much, you should break this out to a SAN network and a GbE internet/management network. If you don't want to set up another GbE network, you need to have the fileserve act as a router, breaking your network into multiple subnets, or do L2 bridging, this should be the least complex of the two. A L2 bridge will have the fileserver acting as a switch with GbE and 40GbE links and a LAGG with the four 10GbE links. This will allow the sonicwall to do DNS, DHCP, and internet routing. I have not done bridging in windows before so you will have to look that up(maybe start
here). I would start with getting the LAGG set up to your 10GbE switch(which I am assuming you have) then move to the bridging the GbE link to both the 40GbE and 10GbE. If you add another network, you can do a subnet for the 10GbE and a subnet for the two 40GbE nodes. When accessing the file server, just use the IPs on the corresponding networks.
The latter is what I have set up, I have GbE to everything, two QDR cards in my file server, and one in my test box and one in my desktop. The two QDR p2p links are each on their own subnets.
Hope this helps, looks like a wall of text to me right now.