Performance losses with virtualization ::comparing bare metal to VMs and containers

The use of virtualization technologies has become widespread with the advent of cloud computing. The purpose of this study is to quantify the performance losses caused by all kind of virtualization/containerization configurations. A benchmark suite consisting of tools that stress specific components and then four real applications commonly used in computing centers has been designed. A system to schedule the execution of these benchmarks and to collect the results has been developed. Finally, a procedure calling all the benchmark in a consistent and reproducible way either within a container or in a (virtual or not machine) has been implemented. These developments permitted then to compare bare metal with four hypervisors and two container runtimes as well as the mix of containers in the virtual machines. The results show that the performance differences vary greatly depending on the workload and the virtualization software used. When using the right virtualization software, the estimated the performance losses are around 5% for a container and 10% for a virtual machine. The combination of the two entails the addition of these losses to 15%. In the case of non-optimized software, a performance loss of up to 72% can be observed. We also observed that containers and virtual machines can over-perform bare-metal when it comes to file access. Overall we conclude that virtualization has become very mature and performance losses seems not to be a concern anymore