Performance Evaluation on Server Consolidation Using Virtual Machines

A virtual machine (VM) is a logical machine having almost the same architecture as a real host machine, running an operating system (OS) in it. This is called full virtualization where multiple OSs can run as is in the real host. Many current industries tend to use many virtual servers, which are servers running on VMs, consolidating many physical servers into a single or fewer real machines, resulting in higher resource utilization and smaller space consumption. This is called the server consolidation using VMs. Noticing this tendency we evaluate the virtualization overhead by measuring the performance of the transaction systems running database servers on VMs. Our research objectives are to evaluate the VM overhead and the virtualization overhead for heavy database servers running in VMs. We have found that the total CPU utilization in the two VMs running database servers increases to 2.5 times that in the native system with the same hardware resources, that is, requiring each server native CPU utilization be less than 40%.