MD3200i with 2012 not multipathing properly

Hi,

I have an MD3200i running as the CSV storage for a 2012 Datacenter cluster running on 4 NICs from the host to a switch to the two controllers. I have updated the firmware and used the latest DVD for the installation in 2012.

When I did the installation I used the "Recommended" button to create the sessions and establish the links. Everything seemed to be fine in testing.

However, now the system is live I can see that the traffic is not being balanced across the NICs, but simply all coming out of one NIC. To the extent that 1 NIC was using 560MBps for 30 minutes without the other NICs getting about 30kbps.

Is there something I must do to enable Multipath? Or have I misunderstood what it is supposed to do? Is it just for fail-over rather than load-balancing?

Thanks and regards

Andrew Smith.