What Is a Virtual Machine (VM)?

With the increasing need for computing power and the growing importance of cloud computing services, virtual machines are becoming the golden standard of the IT industry. In 2023, the virtual machine market was valued at $2.5 billion in the US alone – and that number is projected to quadruple by 2033 (up to $10.3 billion). In this article, we’re diving into why.

What Is a Virtual Machine (VM)?

A virtual machine (VM) is a software-based imitation of a physical computer that allows you to run programs, an entire operating system, and apps without needing extra hardware. It works by combining the physical “host” machine and multiple virtual “guest” machines – each running different operating systems but in the same environment.

Virtual Machines – Use Cases

• Development and testing environments: VMs let developers test applications across multiple operating systems and configurations without needing a separate physical machine, which saves both time and resources.
• Support DevOps: VMs allow teams to easily create, destroy, and replicate environments, which is how they help make the deployment processes smoother and faster.
• Disaster recovery and backup: VM snapshots allow for quick backups and easy restoration. This results in a quicker recovery in case there’s data loss or some hardware failures.
• Malware analysis: Security researchers use VMs to safely study malware behavior in a controlled, isolated environment. This way, they can detect any abnormalities without putting the main system in danger.
• Cloud computing: Since they enable multiple virtual environments to run without the need for physical hardware, VMs are the foundation of cloud computing.

How Do Virtual Machines Work?

A virtual machine works using a technology called “hypervisor.”

The hypervisor is sort of like a special software layer that enables a single physical computer (the host) to run multiple virtual machines (the guests). By dividing the physical computer’s resources – such as CPU or memory – the hypervisor makes sure that each VM gets its own share and is powered to fulfill its function.

There are two types of hypervisors:

• Type 1 (bare-metal): Runs directly on the hardware (like VMware ESXi or Microsoft Hyper-V). Often used in data centers.
• Type 2 (hosted): Runs on top of an existing operating system (like VirtualBox or VMware Workstation). Often used on personal computers.

Both types are essential for virtual machines to work – they’re kind of like a buffer between the physical host and VMs, managing all the communication and resource distribution.

Types of Virtual Machines

• System VM: Think of this as a "full computer" running on top of another computer. It’s fully virtualized, which means it acts just like a complete physical machine with its own operating system and applications. You can do anything on it that you’d do on a physical computer, like installing software or running multiple programs.
• Process VM: This is a smaller, lighter type of virtual machine created just to run one specific program or process. It only exists while that program is running and disappears as soon as the program ends. Process VMs are perfect for tasks that need isolation and portability but don’t need an entire operating system.

The Benefits of Virtual Machines

• Flexibility
• Scalability
• Security
• Portability
• Reduced footprint and costs
• Agility and speed
• Resource efficiency

The Challenges of Virtual Machines

While there are many upsides to using virtual machines, it doesn’t mean they are the perfect, issue-free solution. Some of the most important disadvantages of VMs are:

• Performance issues: VMs often share physical resources like CPU, memory, and storage, which can lead to slower performance compared to running directly on dedicated hardware, especially if resources are over-allocated.
• Security and compliance: One of the biggest challenges of VMs is their security – including those related to VM sprawl, which is the uncontrolled creation of virtual machines and vulnerabilities in the hypervisor layer that could potentially expose all VMs if breached.
• Compatibility issues: Some software or hardware may not be fully compatible with virtualized environments. While not the biggest problem on the list, it can limit the scope of what can be run on a virtual machine or cause them to require additional configurations 

The Difference Between Container and Virtual Machine

Similarly to virtual machines, containers provide an isolated environment for applications to run on a single host system. The key difference, however, is that VMs have their own operating systems, whereas containers share the host operating system, which makes them lighter and faster. Ideally, they can work together and complement each other, bringing the best of VMs’ strong isolation and containers’ agility. 

Summary

Virtual machines represent a powerful tool for optimizing computing resources and introducing more flexibility in IT environments. Projected to grow at a CAGR of 15% from 2024 to 2033, they are the future of scalable solutions and modern tech infrastructure.