Virtual Machines

Virtual machines (VMs) are software emulations of physical computers. They provide the functionality of a physical computer, running an operating system and applications as if they were installed on a hardware system. Essentially, VMs are isolated software containers that can run their own operating systems and applications as if they were separate computers.

Each VM is isolated from others and from the host system. This means the software within a VM can't interfere with the host or other VMs. This isolation provides a secure and stable environment for running different applications. VMs allow multiple operating systems to run concurrently on a single physical machine. For example, you could run Windows, Linux, and macOS on the same hardware.

VMs share the physical resources of the host machine (such as CPU, memory, and storage), but these resources are allocated to each VM in a controlled manner. VMs can be easily moved, copied, and reassigned between host servers more easily than physical hardware, allowing for flexibility in managing computing resources.

VMs can be snapshotted to capture their current state, and can be cloned to create exact replicas. This is particularly useful for backup, testing, and deployment scenarios.

VMs provide developers and testers with isolated environments to run and test applications in different operating systems and configurations without affecting the host system. In data centers, VMs are used to optimize server utilization, allowing multiple virtual servers to run on a single physical server.

VMs can be used for running different operating systems on a single physical workstation or for providing secure, isolated environments for running potentially risky applications. VMs provide a safe and controlled environment for educational purposes, allowing students to experiment with different operating systems and network configurations.

Several technologies enable virtualization, including:

  • VMware: Offers various products for virtualization, including VMware Workstation for desktops and VMware ESXi for servers.
  • [[Hyper-V|Microsoft Hyper-V]]: A hypervisor-based virtualization platform integrated into Windows Server and also available on Windows 10/11 Pro and Enterprise editions.
  • Oracle VirtualBox: A free and open-source virtualization tool that is suitable for desktop virtualization.
  • KVM (Kernel-based Virtual Machine): A Linux-based virtualization solution.