Assuming you are not using the N1K software switch than right now the only option is to use load balancing within ESX. vPC should be available in the next release of code for the N5K.
As far FCOE, I'm pretty sure you can run it over a vPC link but I don't think automatic failover will occur at the hardware level. You'll still have to use some form of FC load balancing software on ESX.
With N1KV you can do vPC-HM (vPC - Host mode). We load a Virtual Ethernet Module on the ESX host that will vPC the two CNAs together. This only works when the two CNAs are connected to different N5Ks. If you connect the two CNAs to the same N5K then you have to use standard Etherchannel.
I can check on the availability of the N5K code, but i think its still in beta.
Thank you Louis. Let me make sure I understand the subtleties. With vPC-HM I'm basically letting the N1Kv do the balancing so a single VM will only use one uplink connection? Not a big deal for us here since that single uplink is 10Gb. But I want to make sure I understand what is happening. Once the N5K supports vPC the N1Kv will just use a standard port-channel that it thinks is to the same upstream switch and therefore can balance a single VM traffic across both connections, correct?
On the N1KV with vPC-HM it will use both connections for uplink. So it is active/active on the N1KV. We support something like 14 load balancing algorithms on the N1KV with vPC-HM.
If you have one N5K than yes you would run etherchannel. If you have multiple N5Ks I'm not sure how the hardware vPC on the N5K is going to integrate with vPC-HM on the N1KV.
I'll try and find out more info on what they plan to do.