Virtualization: what is it?

Virtualization is the process of running a virtual instance of a system computer science in an abstract layer of the real hardware. Most often, it is a question of simultaneously executing several Operating systems on a computer system. For the apps running within the virtualized machine, it may appear as if they are on their own dedicated machine, where the operating system, libraries, and other programs are unique to the guest virtualized system and unrelated to the host operating system in which it is.

The use of virtualization

There are many reasons why people use the virtualization In computer science. For users ofcomputers desktop, the most common use is the ability to run applications intended for a different operating system without having to switch computers or reboot into a different system. For server administrators, virtualization also provides the ability to run different operating systems, but, perhaps more importantly, it provides a way to segment a large system into several smaller parts, allowing the server to be used more efficiently by a number of users or applications with different needs. It also makes it possible to isolate the programs executed in a virtual machine processes that take place in another virtual machine on the same host.

Hypervisor and virtual machines

A hypervisor is a program for creating and running virtual machines. Hypervisors are traditionally divided into two categories: Type 1 hypervisors, or bare metal which run guest virtual machines directly on a system’s hardware, essentially behaving like an operating system. Type two, or “hosted,” hypervisors behave more like traditional applications that can be started and stopped like a normal program. In modern systems, this division is less common, especially with systems like KVM. KVM, abbreviation of ” kernel-based virtual machine ‘, is part of the core linux which can directly run virtual machines, although you can still use a system running KVM virtual machines like a regular computer. KVM brings together the best of both worlds by offering very good performance thanks to access to the software layers closest to the hardware while isolating the system.

A virtual machine is a computer system that runs inside another system. Virtual machines can have access to a number of resources: computing power, through limited but hardware-assisted access to the processor and to the memory of the host machine; one or more discs physical or virtual for storage; a virtual or real network interface; as well as any peripherals such as video cards, USB devices, or any other hardware shared with the virtual machine. If the virtual machine is stored on a virtual disk, it is often referred to as a disk image. A disk image can contain the files for a virtual machine to boot, or it can contain any other specific storage needs.