VMware vSphere DirectPath I/O leverages Intel VT-d and AMD-Vi hardware support to allow guest operating systems to directly access hardware devices. In the case of networking, vSphere DirectPath I/O allows the VM to access a physical NIC directly rather than using an emulated device or a paravirtualized device. An example of an emulated device is the E1000 virtual NIC, and examples of paravirtualized devices are the VMXNET and VMXNET 3 virtual network adapters. vSphere DirectPath I/O provides limited increases in throughput, but it reduces the CPU cost of networking-intensive workloads.
vSphere DirectPath I/O is not compatible with certain core virtualization features. However, when you run ESXi on certain vendor configurations, vSphere DirectPath I/O for networking is compatible with the following:
- VMware vMotion
- Hot adding and removing of virtual devices, suspend, and resume
- VMware vSphere high availability
- VMware vSphere Distributed Resource Scheduler...