We have a situation where we need to use fixed paths for our iSCSI storage. We are using the software initiator. The reason is we have HP P4000 VSA's running as virtual machines. We are also using 10Gb Emulex cards with the virtual nic mode (UMC)
Normally we would put the vmk ports and the P4000 VM port group on the same vSwitch to reduce the number of NICs required. When we do this we see very high latency to the storage. The only way to reduce the traffic is to force the connection out of a different vswitch so it hits the physical network. HP are still looking into this for us but basically if the vmk port connection to the storage is going to a port group on the same vswitch and not hitting the physical network we see massive latency.
We still want to keep a vmk port on the same switch as the VSA for potential failover (high latency is better that having no access at all, and also reduce the number of 10Gb ports we need). But in normal operation all traffic would be forced across the physical network.
I assume the first VMK port will be given the controller ID 0 in terms of the runtime name. But is there anywhere we can list this to be certain. I could go pulling cables out to identify them but that isn't ideal.
For example I need to know that vmhba36:C0:T14:L0 is using vmk2 & vmhba36:C1:T14:L0 is using vmk3