Hypervisor Virtualization Software

A hypervisor, also known as a virtual machine manager/monitor (VMM), is computer hardware platform virtualization software that allows several operating systems to share a single hardware host. Each operating system appears to have the host’s processor, memory, and resources to itself. Instead, the hypervisor is controlling the host processor and resources, distributing what is needed to each operating system in turn and ensuring that the guest operating systems/virtual machines are unable to disrupt each other.

The term ‘hypervisor’ originated in IBM’s CP-370 reimplementation of CP-67 for the System/370, released in 1972 as VM/370. The term ‘hypervisor call’ refers to the paravirtualization interface, by which a guest operating system accesses services directly from the higher-level control program. This is the same concept as making a supervisor call to the same level operating system.

Hypervisor Classifications

Hypervisors are classified into two types:

Bare Metal/Native Hypervisors— Software systems that run directly on the host’s software as a hardware control and guest operating system monitor. A guest operating system thus runs on another level above the hypervisor. This is the classic implementation of virtual machine architectures.

A variation of this is embedding the hypervisor in the firmware of the platform, as is done in the case of Hitachi’s Virtage hypervisor and VMware ESXi. See below definition.

Embedded/Host Hypervisors— Software applications that run within a conventional operating system environment. Considering the hypervisor layer being a distinct software layer, guest operating systems thus run at the third level above the hardware.

Regardless of how you decide to use hypervisors in your virtual environment, Tricerat’s suite of desktop management software promises to ease the problems frequently encountered in all environments, including VDI. Learn more about Tricerat’s VDI management solutions.