Type 1′ hypervisor and a ‘Type 2′ hypervisor

Type 1 hypervisor (Bare-Metal Architecture) – This is a hypervisor that runs directly on a given hardware platform. A Guest OS then runs at the second level above the hardware. The classic type 1 hypervisor was CP/CMS, developed at IBM in the 1960s. Often quoted examples of this type are Xen, VMware’s ESX Server and IBM’s LPAR hypervisor (PR/SM)..

Type 2 hypervisor (Hosted Architecture) – This is a hypervisor that runs within an OS environment. A Guest OS then runs at the third level above the hardware. Some examples quoted of this type are VMware Server and Linux KVM.