Virtual Machines: A Beginner’s Guide to Virtualization

Virtual machine

Virtual machines have been growing in popularity recently, with many people and companies looking to learn more about the benefits. Virtualization has become an important way for businesses to cut IT costs, enhance security, and increase operational efficiency. Organizations are using virtual machines, also referred to as VM, for storage virtualization, network and data virtualization, application virtualization, and virtual desktop infrastructure, typically shortened to VDI. In this guide, we will cover everything you need to know about virtual machines.

What Are Virtual Machines?

Virtual machines are guest operating systems or applications that run on physical machines, typically called a host, but give you the perception of working in a separate physical box. For instance, suppose you have Linux and Windows operating systems installed on the same computing device. When you are using the Windows operating system, it will provide you with a different look and feel compared to when you are using the Linux OS. Additionally, you cannot see your Linux documents in the Windows OS and vice-versa; this supplies a perception that each operating system is linked to a separate device when they are actually connected within the same computer.

You can also use the same computing device for both your production and test environments, which means what you do in the test environment does not impact your data or the application in the production environment. This differentiation is accomplished through virtualization software that emulates dedicated hardware, which ensures your experience on a VM is the same as when on a dedicated server. 

Not to be confused with containers that create isolated logical namespaces on the underlying operating system such as Linux, VMs contain and run a full operating system on underlying virtualized hardware resources. If you’re interested in learning more about the difference between containers and virtual machines, which are both essential tools used in cloud-based services and applications, check out Virtasant and their expert article on virtual machines.

How Do They Work?

Virtualization is a process where you create a software-based, virtual version of a computer, with dedicated amounts of memory, CPU, and storage that are borrowed for a physical computing device such as a personal computer or a remote server such as a server in a cloud datacenter. A virtual machine is a file on your computer, typically called an image. It behaves like a separate computer, running in a window as an independent computing environment, often in order to run a different operating system or to function as the user’s entire computer experience. The VM is partitioned away from the rest of the computing systems, which means that the software contained within the virtual machine can’t interfere with the host’s primary operating system.

SEE ALSO: Physical vs. Virtual Memory

What Are Virtual Machines Used For?

There are many uses for virtual machines, and many users utilize VMs for a range of tasks, including building and deploying apps to the cloud, trying out new operating systems, and spinning up new environments to make it more simple for developers to run dev-test scenarios. Additionally, you can also use VMs to back up your existing OS, access virus-infected data, run old applications on historical operating systems, and run software or apps on an OS they weren’t initially intended for.

Benefits

While virtual machines run as separate computers with independent operating systems and applications on the host machine, they have the advantage of remaining detached from any other VMs installed and the physical host machine. A hypervisor, also known as a virtual machine manager, provides you with the option to run different operating systems on several VMs at the same time; this makes it possible to run Linux on a Windows OS or run an earlier version of Windows on the most recent Windows operating system. As a result of VMs being independent of each other, they are also flexible and portable as you can move a virtual machine from one hypervisor to another on a completely separate machine almost instantaneously.

  • Cost savings: With the ability to run multiple virtual environments from a single infrastructure, you can significantly reduce your physical infrastructure footprint. As a result, this boosts your bottom line, which decreases the need to maintain multiple servers as well as saves on maintenance costs and electricity.
  • Agility and speed: Spinning up a virtual machine is a relatively quick and straightforward process that means you don’t need to provide an entirely new environment for your developers.
  • Lowered downtime: Due to VM’s portability and how easy it is to move from one hypervisor to another on a different machine, they are an excellent backup solution, especially in the event the host goes down unexpectedly.
  • Scalability: Virtual machines provide you with the ability to scale your apps by adding extra physical or virtual servers to distribute the workload across various VMs. This means you can increase the performance and availability of your apps.
  • Security benefits: As VMs run in multiple operating systems, using guest operating systems on a virtual machine enables you to run apps of questionable security while protecting your host operating system. Additionally, VMs also allow for better security forensics as they are frequently used to safely study computer viruses by isolating the viruses from the host to avoid risk.

Types Of Virtual Machines

Virtual machines can be classified into two types; the first one is called a system virtual machine which mimics the processes and components of an actual computing device. A system virtual machine allows you to use a single server as though it was several machines, and it even provides you the option of running multiple operating systems on it.

The second type of virtual machine is called a process virtual machine, and this is used to run a single process or application. In contrast to the system virtual machine, a process virtual machine does not exist when the application or process is not in use and is mainly used to run programs that are incompatible with underlying operating systems.

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How To Scale A Virtualization Setup

When it comes time to scale up your virtualization setup, the most cost-effective way to do this with an existing virtualization system is by adding additional memory. Adding extra memory to your host machine will provide you with the ability to run more virtual machines concurrently while also improving the overall performance of your VMs and host. 

For example, suppose your virtual machines are running on a 32-bit Microsoft Virtual Server; this means the VMs are restricted to roughly 3.6GB of physical memory. When you increase the memory in the host machine in line with the amount of memory supported by the host device’s operating system, you can expand the memory of each VM installed on the host, which will, in turn, lead to better overall performance. You may even have the opportunity to install more virtual machines on the host device if there is the memory capacity to support it.

Backing Up A Virtual Machine

In order to back up your virtual machines, you will need to use tools such as Windows Backup to create your backup files and copy them to a host or external device. Alternately, you could also use a cloud backup service that supports VMs to store all your data in the cloud, but you will most likely be required to install third-party software to back up your files on the cloud.