Virtualization overhead findings of four hypervisors in the CloudStack with SIGAR

Virtualization increases the utilization of physical servers and enables portability of virtual servers between physical servers. Virtualization Technology plays an important role in the success of cloud computing as it optimizes hardware and software resources which in turn enables cloud model to deliver the services in a scalable manner. Hypervisor as a virtualization layer provides an infrastructural support to multiple virtual machines above it by virtualizing hardware resources such as CPU, Memory, Disk and NIC. Cloud computing model and virtualization technology both increases the scalability of IT infrastructure but with an overhead of the performance as Hypervisors may not give near native performance. It is encouraging to study how different Hypervisors perform in the Private Cloud as compared to the native system. Hypervisors do come in Para-virtualized [XenServer], Full Virtualized [ESXi] and Hybrid [KVM] flavors. Hyper-V uses microkernelized design. It is novel idea to compare them in the Private Cloud environment. In the experiment, we have created our private cloud using CloudStack. This paper uses SIGAR (System Information Gatherer and Reporter) framework to compare four hypervisors namely XenServer, ESXi, Hyper-V and KVM.