We're wanting to use our Nexus 5596UPs to create a pair of FCoE fabrics. We have currently got stretched layer 2 between our datacentres via Nexus 7ks in each datacentre. My question is around having a pair of 5596's in each room. If we want to extend our FCoE fabric between the rooms using the Nexus 7k's as a backbone, do the Nexus 7k's have to be a part of the fabric (as in give them each domain IDs etc), or do the 7k's just have to be able to see the layer 2 VLANs for each VSAN and pass the frames to the 5k at the other end?
Essentially I would like to have a VE_Port on 5596-01 in room A on VLAN 200 and have the next FC hop land on a VE_Port on 5596-02 in room B. The 5k's will both be connected via 7k's in each room. Both 7k's will be able to see VLAN 200. Will we require a storage VDC on each 7k with its own uplinks to the other 7k to handle FCoE traffic? Is this only required if we want to have FCoE devices (like arrays etc) hanging off the 7k as well (which we don't intend to)?
From what I can gather, the 7k's will only be handling ethernet traffic and it would be unaware of the fact that the ethernet frames are carrying FC traffic but I'm not 100% sure, so I'm hoping somebody out there has experience in stretched fabrics.
Hopefully this makes sense. I'm happy to provide clarification if required, but any advice would be appreciated.