The main goal of virtualization is to manage workloads by radically transforming traditional computing to make it more scalable. Virtualization has been a part of the IT landscape for decades now, and today it can be applied to a wide range of system layers, including operating system-level virtualization, hardware-level virtualization and server virtualization.
The most common form of virtualization is the operating system-level virtualization. In operating system-level virtualization, it is possible to run multiple operating systems on a single piece of hardware. Virtualization technology involves separating the physical hardware and software by emulating hardware using software. When a different OS is operating on top of the primary OS by means of virtualization, it is referred to as a virtual machine.
A virtual machine is nothing but a data file on a physical computer that can be moved and copied to another computer, just like a normal data file. The computers in the virtual environment use two types of file structures: one defining the hardware and the other defining the hard drive. The virtualization software, or the hypervisor, offers caching technology that can be used to cache changes to the virtual hardware or the virtual hard disk for writing at a later time. This technology enables a user to discard the changes done to the operating system, allowing it to boot from a known state.
Virtualization can be categorized into different layers: desktop, server, file, storage and network. Each layer of virtualization has its own set of advantages and complexities. The technology offers many benefits, including low or no-cost deployment, full resource utilization, operational cost savings and power savings. However, deploying virtualization technology requires careful planning and skilled technical experts. Since the virtual machines use the same resources to run, it may lead to slow performance.