What is a virtual machine (VM)?

Virtual Machine (VM): Everything you need to know!

A Virtual Machine is basically a compute resource, usually called an image that behaves just like a real computer. It uses software instead of a physical computer to run programs and deploy apps.

You can also say that a virtual machine (VM) is a virtual environment that functions as a virtual computer system with its own CPU, memory, network interface, and storage, created on a physical hardware system (located off- or on-premises).

Public cloud provides such as Azure, AWS, GCP or any other are using virtual machines to provide virtual application resources to multiple users at once, for even more cost efficient and flexible compute.

How do VMs work?

The core technology behind virtual machines is Virtualization.

Virtualization is like a superpower that lets you do something really cool: creating lots of virtual machines on just one computer. Each virtual machine has its own operating system and apps, just like having multiple computers in one! Refer the image above.

Virtualization makes it possible to create multiple virtual machines, each with their own operating system (OS) and applications, on a single physical machine.

But here's the thing: these virtual machines can't talk directly to the real computer. They need a special software called a hypervisor to be the middleman. The hypervisor is like a traffic cop, making sure each virtual machine gets what it needs from the actual computer.

The hypervisor is pretty smart. It knows how to divide up the physical stuff like processors, memory, and storage among all the virtual machines. It keeps each one separate, so they don't mess with each other or cause any trouble.

So, thanks to virtualization and the hypervisor, you can have a bunch of virtual machines running different operating systems and apps, all on one physical machine. It's like having a whole team of computers working together, each with its own little world. It's pretty amazing!

What are virtual machines used for?

Virtual machines offer numerous uses and benefits across various scenarios. Let's explore some of the common applications of virtual machines, including the ones you mentioned:

• Building and Deploying Apps to the Cloud:

Virtual machines provide an ideal environment for developing, testing, and deploying applications in the cloud. Developers can create VMs with the necessary configurations, libraries, and dependencies to ensure consistent deployment across different cloud platforms.

• Trying out a New Operating System (OS):

Virtual machines enable users to experiment with different operating systems without impacting their primary system. Whether it's testing a beta release of an upcoming OS or exploring an alternative OS, VMs provide a safe and isolated environment to evaluate and familiarize oneself with new software.

• Dev-Test Scenarios:

Virtual machines are valuable for developers as they can quickly spin up new environments to test their applications or software configurations. This helps in identifying issues, debugging code, and ensuring compatibility across different platforms or versions.

• Backup and Disaster Recovery:

Virtual machines are instrumental in creating backups of existing operating systems. By encapsulating the entire OS and its configurations within a VM, organizations can easily restore systems in case of data loss or system failures. VM backups provide a reliable and efficient disaster recovery solution.

• Running Legacy or Incompatible Applications:

Virtual machines allow running older or incompatible software or applications on newer operating systems. By installing the older OS within a VM, users can access legacy systems or run applications that may not be compatible with the host OS.

• Cross-Platform Compatibility:

Virtual machines enable running software or apps on operating systems they were not originally intended for. For example, running Windows applications on a Mac using a Windows VM or using Linux-specific tools on a Windows machine through a Linux VM. This flexibility eliminates the need for separate hardware or dual-boot setups.

What are the benefits of using VMs?

Well when it comes to benefits, virtual machines have many. Let's look few of them:

• VMs Are Cost-effective:

Virtual machines offer cost savings as they eliminate the need for investing in multiple hardware devices. With virtualization, you can consolidate multiple servers onto a single physical server, reducing hardware costs. Additionally, maintenance costs are reduced as all the virtual machines are stored and managed on the same server.

• Easy Portability:

Virtual machines are stored as files on your device, making them easy to move and transport. You can copy and transfer them to a USB device and later install them on different hardware or assign them to a different host server. This portability provides flexibility and convenience in managing and deploying virtual machines.

• Enhanced Security:

Virtual machines provide a secure environment for various purposes. As each VM operates in an isolated virtual environment, any actions or changes made within a VM do not affect the primary system, ensuring safety and stability. This isolation makes virtual machines popular among users concerned about security. VMs can be used to access potentially unreliable websites or download suspicious software without risking the main system.

• Scalability:

Virtual machines allow you to more easily scale your apps by adding more physical or virtual servers to distribute the workload across multiple VMs. As a result you can increase the availability and performance of your apps.

• Testing and Experimentation:

Virtual machines are perfect for testing and experimenting with different software or applications. By using a VM, you can push an application to its limits without worrying about damaging the host system. If the VM's operating system becomes damaged during testing, features like snapshots or backups allow you to revert to a previous version of the OS, effectively restoring the VM to its previous state. This capability is helpful in troubleshooting, removing compromised OS instances, or undoing changes made during experiments.

Virtual machine vs container?

Let's break down the differences between virtual machines and containers in simple terms:

• Virtual Machines (VMs):

In traditional virtualization, we use a special software called a hypervisor to create virtual machines. Each virtual machine acts like a separate computer with its own operating system (like Windows or Linux), applications, and everything it needs to run. It's like having different computers inside a single physical machine. So, you can have a Windows virtual machine, a Linux virtual machine, and more, all running on the same computer.

• Containers:

Containers, on the other hand, work differently. Instead of virtualizing the whole computer, containers focus on virtualizing just the operating system (usually Linux or Windows). Each container contains only the specific application it needs to run and its related stuff like libraries and dependencies. This makes containers very small, fast, and easy to move around. Unlike virtual machines, containers don't need a separate operating system for each one. They use the operating system of the computer they're running on.