Data plane vNICs should be configured with the paravirtual VMXNET3 driver. The paravirtualized VMXNET3 NIC has improved performance compared to other virtual network interfaces. VMXNET3 provides several advanced features such as multi-queue support, Receive Side Scaling (RSS), IPv4 and IPv6 offloads, and MSI and MSI-X interrupt delivery, interrupt coalescing algorithm, and Large Receive Offload (LRO).
To benefit from the performance and efficiency of N-VDS Enhanced, a data plane intensive VNF-C must use the VMXNET3 poll mode driver (PMD) as its vNIC. VMXNET3 is included in several modern Linux distributions such as Red Hat Enterprise Linux and SUSE Linux starting from the 2.6.32 release in October 2009. Although the VMXNET3 driver is included in the Linux distributions, you must also install VMware Tools on the VM. See VMware support for Linux inbox VMware drivers (2073804) for more information. For more information about the DPDK support in the VMXNET3 driver, see Poll Mode Driver for Paravirtual VMXNET3 NIC.
The interrupt coalescing algorithm and LRO are disabled if the sched.cpu.latencySensitivity property on the VM is set to High. However, this is not an issue when the VNF-Cs use the VMXNET3 PMD.
Recommendations
- Use the paravirtualized VMXNET3 vNIC with VNF-Cs.
- Install and use the VMXNET3 PMD.
- Install VMware Tools.
