ISCSI multipathing and multiple ISCSI SANS in a single ESXi 5.1 cluster

Hi,

We have two Dell MD3660i ISCSI SANs.

We have a dedicated ISCSI storage network (physically isolated 10GbE switches )

We have 10 ESXi hosts in a single cluster each with one dual port 10 GbE NIC dedicated for storage networking

Note -

The Dell SANs each have two controllers. Each controller has one dual port 10GbE NIC. Dell insist that to utilise both 10GbE ports in each controller efficiently, each port in each controller has to be on its own subnet. For this purpose I can probably use two subnets per SAN distributed between controllers

So we end up with say with 4 subnets and 4 VLANs on the storage network.

I immediately have a problem as there should be a 1:1 ratio of vmk to physical NIC and subnet on ESXi, and I only have two physical 10GbE ports in each host.

Is it safe to break the 1:1 ratio rule? Are there any workarounds (apart from adding more cards)?

Assuming I have set this all up somehow breaking the 1:1 ratio rule, and I go to add the vmks to the ISCSI software adapter. How does the ISCSI multipathing know which SAN is which when a link goes down?

Thanks