Virtualization

What is virtualization?

Virtualization is a computing term used to define running a virtual instance of a computer system in a layer abstracted from the actual hardware, i.e., simulating another program or hardware. Virtualization is often used to refer to most commonly to running multiple operating systems on a computer system simultaneously. The programs run on a virtual machine appear as though they are on their own dedicated machine. On a virtual machine, the operating system, libraries, and other programs are unique to the guest virtualized system and unconnected to the host operating system which sits below it.

Virtualization is used for a handful of reasons in the computing world. Some people use this technology to run applications meant for a different operating system without having to switch computers or reboot into a different system. Server admins can utilize virtualization to run different operating systems. Still, more importantly, it’s used as a way to segment a large system into many smaller parts, allowing a single server computer to be used more efficiently by several different users or applications with different needs. With virtualization, two tasks can be run simultaneously and in isolation as programs running inside a virtual machine are unrelated to the processes in another virtual machine on the same host.

How does virtualization work?

Virtualization refers to the process by which an application, guest operating system (guest OS), or data storage is abstracted away from the true underlying hardware or software. One of the major uses of virtualization is server virtualization, which uses a software layer called a hypervisor to recreate the underlying hardware. Virtual hardware can range from the CPU’s memory, input/output (I/O), and network traffic. Hypervisors are programs that share computers hardware resources between the virtual and physical environment. Hypervisors can exist above an OS or can be infused directly with the hardware beforehand. Most large organizations use the latter method to virtualize their processes.

A common hypervisor is the Xeb hypervisor which is an open-source software program. This hypervisor is responsible for managing the low-level interactions between virtual machines (VMs) and the physical hardware. To put it in different terms, you can say that the Xen hypervisor enables the simultaneous creation, execution, and management of various virtual machines in one physical environment.

The hypervisor allows the guest OS to do so much more like an emulation with the true hardware. Naturally, virtualized operating systems don’t have the same performance values as running on true hardware. The guest OS also doesn’t have a clue that it exists on virtualized hardware. This is hardly ever a challenge, however, as the concept of virtualization works because most guest operating systems and applications don’t need the full ability of the underlying hardware. This virtualization enables greater flexibility, control, and isolation by removing the dependency on a given hardware platform. Virtualization was initially created for server virtualization, but today, the concept of virtualization has spread to applications, networks, data, and desktops.

Steps of virtualization

  • The hypervisors first exclude the physical resources from their physical environments.
  • These resources are now separated from the physical environment to the various virtual environments.
  • An OS is then installed on the virtual machine, and now, users can work with and perform computations within the virtual environment.

While the virtual environment exists, users or programs can send instructions requiring extra resources from the physical environment. The hypervisor then takes this instruction and merges the physical resources for a moment to perform that task( this happens at almost native speed). Virtual environments are often called guest machines or virtual machines. Virtual machines can be transferred from one computer to another and opened in both; it is expected to perform the same way on every computer.

Types of virtualization

Everyone has come in contact with one form of virtualization or the other as long as you have used a computer. You’d have a clue about virtualization if you have ever divided your hard drive into different partitions. A partition utilizes virtual technology to divide a physical hard drive to create what seems to be two separate drives.

Virtualization is used majorly in these six ways.

  • Network virtualization.  This virtualization technique involves combining the available resources in a network by splitting up the available bandwidth into channels. Each channel is independent of the others and can be assigned or reassigned to a particular server or device in real-time. It’s a concept that uses virtualization to disguise the true complexity of the network by separating it into manageable parts. Yourpartitioned hard drive makes it easier to manage your files.
  • Storage virtualization. This type of virtualization involves combining physical storage from multiple network storage devices into what appears to be a single storage device that is managed from a central console. 
  • Server virtualization. Server virtualization hides the resources( number and identify) of individual servers, processors, and operating systems from users to make it all look like one enormous server. A hypervisor is responsible for this abstraction.
  • Data virtualization. This type works by abstracting the traditional technical details of data and data management, such as location, performance, or format, in favor of broader access and more resiliency tied to business needs.
  • Desktop virtualization. Desktop virtualization virtualizes a workstation load rather than a server. A user can access the desktop remotely with desktop visualization, typically using a thin client at the desk. With the virtual workstation on a data center server, access to it can be both more secure and portable.
  • Application virtualization. Application virtualization extracts resources to make an application run in an encapsulated form without being depended upon by the operating system underneath. This form of virtualization is used commonly to make Windows applications run on Linux and vice versa.