We have been getting an error "Lost path redundancy to storage device" recently and VMware Support told us that our Port Binding is not setup correctly. We have not made any recent network changes. So not sure how this would happen, as we have had this network setup for about 3 years now.
This is what VMware Support says: "You have 4 vmnics on 2 different networks port bound to 1 iscsi adapter. This is not a supported configuration.
Adjust you port binding and failover to a supported configuration.
iSCSI vmk port binding may be wrong. Please check the vmks below in the environment to see if:
1. they are bound but are in different subnets, or
2. they are in the same vSwitch but are in different subnets"
We do not know how to fix or how to do it.