Virtualization overheads and factors affecting them

Virtualization increasingly penetrating present-day information and communication systems provides them with greater information security due to more reliable mutual isolation of multiple users and applications; it also provides system administrators' management efficiency and essential reduction of operating costs. All these advantages are achieved, however, at the expense of certain overheads that decrease the general performance of a virtualized system as compared with a physical machine. The overheads have a number of components, which depend on a level and degree of virtualization and are influenced by several factors, such as peculiarities of operating systems and hypervisors, or a specific character of the hardware virtualization support within server processors. Achieving satisfactory virtualization effectiveness is unfeasible without understanding the influencing factors and adequate estimation of the extent of influence regarding each of them.