Technology Encyclopedia Home >How does virtualization work?

How does virtualization work?

Created on 2025-06-09 17:59:39
65

Virtualization is a technology that creates a virtual version of something, such as an operating system, server, storage device, or network resource. It allows multiple virtual instances to run on a single physical machine by abstracting and isolating hardware resources. This improves efficiency, flexibility, and scalability by enabling multiple workloads to share the same physical infrastructure.

How It Works:

  1. Hypervisor: A hypervisor (or virtual machine monitor) is the core software that enables virtualization. It manages the allocation of physical resources (CPU, memory, storage, etc.) to virtual machines (VMs). There are two types:

    • Type 1 (Bare-Metal): Runs directly on the host's hardware (e.g., VMware ESXi, Microsoft Hyper-V, KVM).
    • Type 2 (Hosted): Runs on top of an operating system (e.g., VMware Workstation, Oracle VirtualBox).

  2. Virtual Machines (VMs): These are software-based emulations of physical computers. Each VM has its own operating system and applications, but they share the underlying physical hardware via the hypervisor.

  3. Resource Allocation: The hypervisor dynamically allocates CPU, memory, and storage to VMs based on demand, ensuring optimal utilization of the physical host.

  4. Isolation: VMs are isolated from each other, meaning a failure or security breach in one VM does not affect others.

Example:

A company has a physical server with 16 CPU cores, 64GB of RAM, and 1TB of storage. Without virtualization, only one operating system and set of applications can run on it. With virtualization:

  • The hypervisor divides the server into 4 VMs, each with 4 CPU cores, 16GB of RAM, and 250GB of storage.
  • Each VM runs a different operating system (e.g., Windows, Linux) and hosts different applications (e.g., web server, database).
  • If one VM needs more resources temporarily, the hypervisor can reallocate resources from other VMs.

Cloud Computing and Virtualization:

In cloud computing, virtualization is fundamental. It allows cloud providers to offer on-demand resources by pooling physical infrastructure and dividing it into virtual units. For example, Tencent Cloud uses virtualization to provide Elastic Compute Service (CVM), where users can quickly deploy virtual machines with customizable configurations. This enables businesses to scale resources up or down based on workload demands without managing physical hardware.

Another example is Tencent Cloud's Virtual Private Cloud (VPC), which uses virtualization to create isolated network environments within the cloud, allowing secure and flexible networking for applications.