A virtual machine (VM) is a computing resource that runs apps and programs via software rather than a real computer.
On a physical computer called the “host,” one or more virtual “guest” machines operate. Even though they are all running on the same host, each virtual machine has its own operating system and operates independently of the others.
This implies that a physical PC can run a virtual MacOS computer, for instance. Numerous use cases exist for virtual machine technologies in both on-premises and cloud contexts.
Virtual machines are being used by public cloud services more recently to offer virtual application resources to several users simultaneously, resulting in even more flexible and cost-effective computing.
Undoubtedly, this is a perfect explanation of What Does a Virtual Machine Do?
What are Virtual Machines Used for?
With virtual machines (VMs), a company can run an operating system on a desktop app window that functions much like a stand-alone computer.
Virtual machines (VMs) can be set up to execute software that needs a different operating system, to support varying processing power requirements, or to test programs in a secure, isolated environment.
Server virtualization, which allows IT teams to combine their computing resources and increase productivity, has long been accomplished via virtual machines.
Virtual machines can also be used for some tasks that are deemed too dangerous to be carried out in a host environment, such as testing operating systems or accessing data that has been infected with viruses.
The software within the virtual machine is unable to interfere with the host since it is isolated from the rest of the system. Sincerely, this is actually what a virtual machine does
What Does a Virtual Machine Do?
Like any other application, the virtual machine runs as a process in an application window on the physical machine’s operating system. A virtual machine’s configuration file, log file, virtual disk file, and NVRAM setting file are among its essential files.
Advantages of virtual machines
Virtual machines have several benefits over actual machines, including ease of management and upkeep.
Virtual machines (VMs) allow many operating system environments to run on a single physical computer, saving time, money, and physical space.
Virtual machines (VMs) reduce the expense of switching to a new operating system by supporting legacy programs.
For example, a Linux virtual machine with a guest operating system installed that is a Linux distribution can be supported by a host server that runs an operating system other than Linux, such as Windows.
Virtual machines (VMs) can also provide integrated application provisioning and disaster recovery solutions.
Disadvantages of virtual machines
Virtual machines are superior to actual machines in several ways, however, there are also some possible disadvantages:
- If infrastructure criteria are not met, running several virtual machines on a single physical computer may lead to unsteady performance.
- Virtual computers operate more slowly and with less efficiency than a complete real computer. To counterbalance the respective benefits and drawbacks, the majority of businesses combine physical and virtual infrastructure.
The two types of virtual machines
Users can choose from two different types of virtual machines—process VMs and system VMs.
By hiding the details of the underlying hardware or operating system, a process virtual machine offers a platform-independent development environment that enables a single process to operate as an application on a host computer.
The Java Virtual Machine, which lets any operating system run Java apps as if they were native to that system, is an example of a process virtual machine (VM).
A completely virtualized system or virtual machine can replace a real machine. A system platform facilitates the sharing of physical resources between several virtual machines, each operating independently of the host computer’s operating system.
A hypervisor, which can operate on top of an operating system or bare hardware like VMware ESXi, is essential to this virtualization process.
What are the 5 types of virtualization?
Nowadays, it is possible to virtualize every part of a conventional data center or IT infrastructure, using a variety of specialized virtualization techniques.
- Hardware virtualization: Virtualized versions of computers and operating systems (VMs) are built and combined onto a single primary physical server when virtualizing hardware. To control the virtual machines, a hypervisor has direct communication with the CPU and disk space of a physical server. Server virtualization, another name for hardware virtualization, enables one computer to run many operating systems concurrently and optimize hardware resources.
- Software virtualization: Through the use of software virtualization, a physical host computer can run one or more guest operating systems on a fully functional computer system with hardware. For instance, Android OS can run on a host computer that is running Microsoft Windows OS natively, making use of the same hardware. Applications can also be virtualized and sent from a server to a laptop or smartphone owned by the end user. This enables workers who are working remotely to access programs hosted centrally.
- Storage virtualization: By combining several physical storage devices into one, storage can be virtualized and made to seem like a single unit. Benefits include lower expenses, load balancing, and improved performance and speed. Because virtual storage data can be swiftly and reliably replicated to a different site, storage virtualization also aids in disaster recovery planning by minimizing downtime.
- Network virtualization: Equipment can be combined into a single software-based virtual network resource to construct several sub-networks on the same physical network. Additionally, network virtualization splits available bandwidth into several separate channels that can be instantly allocated to servers and other devices. Improved security, network speed, dependability, and data consumption monitoring are among the benefits. Network virtualization is a viable option for enterprises with a large number of users that require constant access.
- Desktop virtualization: With this popular kind of virtualization, users may access their desktops on any device and from any location by storing the desktop environment on a remote server. Virtual desktops have improved data security, reduced costs for software licenses and upgrades, and ease of management, in addition to their ease of access.
Container vs virtual machine.
Container technology, like Kubernetes, is comparable to virtual machines in that it allows segregated applications to run on a single platform.
Containers package up just one piece of software and its dependencies, whereas virtual machines virtualize the hardware layer to create a “computer.”
While container systems use virtual memory hardware to segregate the programs and offer shared operating system functions from the actual host, virtual machines are often managed by hypervisors.
The fact that containers require less overhead than virtual machines is one of their main advantages. Only the program, libraries, and other necessary dependencies are included in containers.
Because they share the same operating system kernel, containers on the same host are substantially smaller than virtual machines. Containers thereby maximize server resources, speed up application delivery, and boot up faster.
Web applications, microservices, DevOps testing, and boosting the number of programs that can be deployed per server are just a few of the use cases where containers have gained popularity.
Compared to containers, virtual machines are larger and take longer to boot. They have their own operating system kernel, are logically isolated from one another, and provide all the advantages of an entirely different operating system.
The best applications to run on virtual machines are monolithic applications, legacy apps that operate on older operating systems, and several applications running simultaneously.
Virtual machines and containers can also be used in tandem.