Container Hosts as Virtual Machines : A performance study

Virtualization is a technique used to abstract the operating system from the hardware. The primary gains of virtualization is increased server consolidation, leading to greater hardware utilization and infrastructure manageability. Another technology that can be used to achieve similar goals is containerization. Containerization is an operating-system level virtualization technique which allows applications to run in partial isolation on the same hardware. Containerized applications share the same Linux kernel but run in packaged containers which includes just enough binaries and libraries for the application to function. In recent years it has become more common to see hardware virtualization beneath the container host operating systems. An upcoming technology to further this development is VMware’s vSphere Integrated Containers which aims to integrate management of Linux Containers with the vSphere (a hardware virtualization platform by VMware) management interface. With these technologies as background we set out to measure the impact of hardware virtualization on Linux Container performance by running a suite of macro-benchmarks on a LAMP-application stack. We perform the macro-benchmarks on three different operating systems (CentOS, CoreOS and Photon OS) in order to see if the choice of container host affects the performance. Our results show a decrease in performance when comparing a hardware virtualized container host to a container hosts running directly on the hardware. However, the impact on containerized application performance can vary depending on the actual application, the choice of operating system and even the type of operation performed. It is therefore important to consider these three items before implementing container hosts as virtual machines