The powerful hardware of modern day computers are designed to run only a single operating system and this typically leaves the hardware highly underutilized. This can lead to a problem called a server sprawl where several underutilized computers are hard to manage, use floor space inefficiently and consume excessive amounts of power. Virtualization provides a solution to server sprawls through server consolidation where several physical servers are migrated to operate on top of single server hardware.

This thesis work discusses virtualization in general along with benefits, drawbacks, uses and providers of virtualization technologies. When discussing about different virtualization approaches the main emphasis is on server virtualization and its four main categories. Physical to virtual server consolida-tion and VMware Infrastructure 3 products are discussed in more comprehensive manner.

The practical part of this thesis consists of physical to virtual consolidation of a single physical server that is running Windows Server 2003 operating system. The destination platform is a Windows Server 2008 virtual machine that is running on top of VMware ESXi 3.5 virtualization platform. After the consolidation process the virtual machine provides exactly the same services as the physical server did before the consolidation. The practical part also briefly monitors and evaluates the performance of the virtualization host and the virtual machine.

The results of this thesis work show that VMware ESXi 3.5 is a powerful virtualization platform with lots of scalability. The free version of VMware ESXi 3.5 provides a good foundation for a virtual infra-structure but should mainly be implemented for testing environments. Larger production environments should provide host redundancy and powerful backups; therefore at least VMware Infrastructure 3 Standard should be purchased.

The main objective of the thesis was to experiment how to eliminate the problem of a server sprawl using virtualization technologies and server consolidation. The results show that the hardware used can host approximately 20 virtual machines and therefore eliminate the server sprawl problem.