Measuring Virtual Networking Overhead
After discussing [ovs-discuss] ovs performance on ‘worst case scenario’ with ovs-vswitchd up to 100%. One of my colleagues had a good idea: tcpdump the physical interface and the vif at the same time. The difference between when the packet reaches the vif and the packet reaches the physical device can help measure the amount of time in a userspace->kernelspace transit. Of course, virtual switches aren’t the only culprit in virtual networking overhead- virtual networking is a very complex topic....