What is virtualization?

Virtualization refers to the abstraction of physical IT resources such as hardware, software, or networks. The goal is to enable flexible, efficient, and scalable use of these resources. Virtualization transforms physical components into virtual environments. For example, a single physical server can host several isolated virtual machines (VMs). Each of these virtual machines has its own operating systems, applications, and configurations. This allows companies to optimize their IT infrastructure and significantly increase resource utilization.

Types of Virtualization

There are various forms of virtualization, depending on the type of abstracted resources:

Server virtualization:
Multiple virtual servers run on a single physical machine. This reduces hardware costs while increasing reliability.
Desktop virtualization:
Users access personalized desktop environments via a central server, which simplifies management and security.
Network virtualization:
Software divides network infrastructures into multiple logical networks, increasing flexibility and security.
Storage virtualization:
Multiple physical storage devices are combined into a single, centrally managed storage resource, improving scalability and performance.
Software virtualization:
Applications are decoupled from the underlying hardware, allowing them to run independently of the operating system or platform.

Virtualization Software

Virtualization is implemented using specialized virtualization software, also known as a hypervisor or Virtual Machine Monitor (VMM). There are two main types:

Type 1 Hypervisor (Bare Metal): Runs directly on the hardware without an underlying operating system, enabling higher performance and efficiency. Examples include VMware ESXi, Microsoft Hyper-V, KVM, and Proxmox VE, an open-source solution that supports both virtualization and container technologies.
Type 2 Hypervisor (Hosted): Installed on an existing operating system and uses its resources for virtualization. Well-known examples include VMware Workstation, Oracle VirtualBox, and other software solutions for smaller or experimental environments.

Modern virtualization solutions offer advanced features: these include live migration, which allows virtual machines to be moved between physical servers during operation, and container technologies (e.g., Docker, Kubernetes), which enable even more efficient resource utilization. Proxmox VE provides a web-based management interface for easy control of virtualized environments.