The advantages of a properly planned for and implemented virtualisation project are great. They include:
Server consolidation: The most often talked about benefit of virtualisation. If applications running on separate computers do not utilise the computing resources of their computers, they can be consolidated onto a smaller number of servers using virtualisation technology. It has been estimated that distributed physical servers generally use only 20 percent of their capacity, and that, by virtualising those server environments, enterprises can boost hardware utilisation to between 60 percent and 80 percent. This relates to a consolidation ratio of 3:1 or 4:1, though some companies have reported consolidation ratios as high as 12:1.
Smaller footprint: Virtualising servers decreases the number of physical boxes that a company must use. This means a smaller datacenter, with the resulting decreases in cooling and electrical costs.
Hardware costs: Because virtualisation allows for greater utilisation of existing resources, fewer physical servers are required, saving money both on upfront hardware costs and on maintenance costs.
Flexibility and agility: Often used buzzwords, "increased agility and flexibility" really do apply to virtualisation. Because virtualisation allows for the quick creation of different operating system environments, it is easy to run legacy applications alongside new versions, migrate applications to new environments, and restore systems in post-disaster scenarios.
Ease of Testing and Development: In a similar vein as above, virtualisation speeds up the development and testing process because it makes it easier to create different operating system environments. Virtualisation allows designers to compare application performance across different operating environments, as well testing out applications in virtual environments (which therefore avoids destabilising the system that users are currently using).