What is a Virtual Machine and How Does It Work?

What is a Virtual Machine?

A Virtual Machine (VM) is software that allows one or more operating systems, along with various applications, to run on a physical device such as a computer or a server. VMs enable users to simultaneously and independently run multiple operating systems on a single physical device without the need for additional hardware.

History of Virtual Machines

The origin of virtual machines dates back to the 1960s and has gradually evolved with technological advancements and emerging needs. IBM was a pioneer in the development of virtual machines. In 1964, IBM introduced the System/360, a multi-programming system capable of running multiple programs concurrently.
In the early 1970s, IBM introduced the VM/370 system, the first true hypervisor for running virtual machines. This system allowed users to run multiple operating systems on a single physical device.
In 1998, VMware was founded and introduced its first virtualization software called VMware Workstation.
The use of virtual machines in data centers and cloud environments increased significantly in the 2000s. During this decade, Microsoft introduced the Hyper-V hypervisor, which enabled virtualization in the Windows operating system.
Today, virtual machines play a crucial and widespread role in information technology. In the following, we will discuss more about the applications of virtual machines in today's IT world.

How Do Virtual Machines Work?

Virtual machines operate using virtualization technology. The entire virtualization process is managed and executed by software known as a hypervisor.
This software virtualizes the CPU, RAM, hard drive, network, and other hardware components of the computer. Through this method, it allocates the necessary hardware resources to each virtual machine according to its needs.

Types of Hypervisors

Hypervisors can be categorized into two main types:

• Bare-Metal Hypervisor: Also known as Type 1 hypervisors, these run directly on the physical hardware without the need for a host operating system. Due to their high performance and efficiency, they are commonly used in enterprise environments and data centers. Notable examples include VMware ESXi, Microsoft Hyper-V, and KVM.
• Hosted Hypervisor: Also known as Type 2 hypervisors, these are installed on top of a host operating system and utilize its resources to run virtual machines. They are primarily suited for personal use, development, and testing. Popular examples include VMware Workstation, Oracle VirtualBox, and Parallels Desktop.

Types of Virtual Machines

Virtual machines have a wide range of applications in the IT world, enhancing efficiency, security, resource management, and cost savings. Key applications of virtual machines include:

• Software Development and Testing: Developers can use VMs to create separate virtual environments for each project, preventing interference between projects and protecting all projects from issues that may arise in any single one.
• Creating Isolated Environments: VMs allow organizations to run different operating systems on a single server, tailored to their specific needs and goals, optimizing resource utilization.
• Cloud Computing: Virtual machines are a fundamental component of Infrastructure as a Service (IaaS), providing scalable and flexible infrastructure deployment in cloud environments.

Disadvantages of Virtual Machines

• Lower Performance Compared to Physical Systems: Virtual machines share the host system’s resources, so they don't have the full power of the hardware.
• Complex Management: Managing and maintaining virtual machines is more complex than physical systems and requires more expertise and knowledge.
• Incompatibility with Some Applications: While many applications can run on virtual machines, some may not install or function properly due to their architectural requirements.

Is Docker a Virtual Machine?

Docker and virtual machines are both virtualization tools, but Docker is not exactly a virtual machine. Docker uses containers for operating system-level virtualization, whereas virtual machines provide hardware-level virtualization. Containers are lighter, faster, and consume fewer resources than virtual machines. Virtual machines run a full operating system, including the kernel and all application layers, making them more isolated and secure but also more resource-intensive. Thus, Docker and virtual machines serve different purposes in virtualization.

Monitoring Virtual Machines in the Moein Monitoring Platform

The Moein monitoring platform currently uses the REST communication protocol to interface with vCenter and ESXi tools, as well as Docker. It extracts extensive information from these tools and monitors their performance indicators. To view all the indicators and parameters monitored by Moein for each tool, click on the name of each tool mentioned above.