Windows OS Virtualization

Windows OS Virtualization is a technology that allows multiple operating systems to run on a single physical computer. Instead of installing an OS directly on hardware, virtualization creates a virtual environment where different systems can operate independently. This improves resource utilization, flexibility, and system management.

Virtualization is widely used in cloud computing, software testing, cybersecurity, and enterprise IT environments. This tutorial aims to provide a brief guide on operating system virtualization and its importance in modern cloud computing platforms.

What is Virtualization?

Virtualization is the process of creating a virtual version of hardware resources, such as CPU, memory, storage, and network. It allows multiple virtual machines (VMs) to run on a single physical machine.

Each VM behaves like a real computer with its own:

• Operating System (Windows, Linux, etc.)
• Applications
• Resources

Understanding OS Virtualization

To begin with, operating system virtualization is an advanced approach through which a physical hardware system may support several virtual systems. The virtual systems, referred to as virtual machines (VMs), are equipped with operating systems that run independently of each other on the same hardware platform. Put differently, all virtual machines have their respective operating systems and appear to be individual computers.

Operating system virtualization can be viewed as an abstracting process. For instance, think of several actors playing different characters on the same stage. While each actor performs individually by following a separate script, they share the same stage resources.

Applications of OS Virtualization

The availability of scalable computing facilities is what fuels the rapid growth of cloud computing, which cannot be achieved without OS virtualization technology.

1. Infrastructure as a Service (IaaS)

IaaS is one of the important models of cloud services where OS virtualization technology is used extensively. It involves the delivery of virtual computers to the users so that they can execute applications without being involved in maintaining any physical computing resources.

2. Multi-Tenancy

OS virtualization facilitates multi-tenancy in the sense that it helps users run their own processes and applications within the same physical computing system while remaining isolated from each other.

3 Elasticity and Scalability

Another important application of OS virtualization in the cloud computing environment is its use for elasticity purposes, which is a key feature of cloud environments. With the help of OS virtualization, organizations can quickly increase or decrease the number of VMs according to their needs.

4. Disaster Recovery & Business Continuity

OS virtualization allows organizations to create virtual replicas (snapshots or clones) of systems. In case of hardware failure or disasters, these backups can be quickly restored, ensuring minimal downtime and maintaining business continuity.

5. Development and Testing of Software Applications

Virtualization enables developers to create multiple testing environments with different operating systems and configurations. This helps in:

• Cross-platform testing
• Bug detection
• Safe experimentation without affecting the main system.

Windows OS Virtualization Process

Windows OS virtualization works through the coordinated functioning of hardware and software components to create multiple virtual machines (VMs) on a single physical system. The process involves the following steps:

1) Hypervisor

The hypervisor is the key component of OS virtualization. This software tool works as a middle layer between hardware and all the OS of virtual machines. Its main function consists of managing and allocating system resources in order to provide proper functioning of virtual environments.

2) Creation of Virtual Machines

After installing and configuring the hypervisor, it is possible to start creating new virtual machines, which will act as individual systems with their own OS, application programs, and other virtualized resources.

3) Resource Allocation

With the help of a hypervisor, each newly created virtual machine will receive the necessary resources in accordance with its needs (processor power, RAM, storage, and network).

4) Virtual Machine Management

The hypervisor provides tools to manage VMs, such as:

• Start, stop, and restart
• Pause and resume
• Snapshot (backup) creation
• Performance monitoring

5) User Interaction

Users interact with virtual machines just like physical computers. They can:

• Install and run applications
• Configure system settings
• Perform updates
• Access files and networks

6) Isolation and Security

A key feature of virtualization is isolation.

Each VM operates independently, meaning:

• Failures in one VM do not affect others
• Data remains secure between environments
• Multiple OS can run safely on the same hardware

Virtualization in Operating Systems

The fundamental concept of operating system virtualization remains constant; however, the methodology of its realization may vary depending on the platform and underlying technology. Currently, the two operating systems that widely utilize virtualization features are Linux and Windows.

Linux Operating System Virtualization

Several methods are employed to achieve virtualization in the Linux operating system, which include but are not limited to Kernel-based Virtual Machine (KVM) and containerization.

• KVM (Kernel-based Virtual Machine): Kernel-based virtual machine (KVM) is a complete virtualization technology in Linux that works on x86-based computers equipped with virtualization capabilities. KVM is capable of converting the Linux kernel into a hypervisor, thereby allowing the computer to simultaneously run several independent virtual machines. In particular, each of the virtual machines possesses individual virtualized hardware components, including a network interface card, storage drive, and graphical interface.
• Containerization (e.g., Docker, LXC): Containerization is one of the lightest techniques used in operating system virtualization. While full virtualization creates an abstract environment for a completely isolated operating system, containers create a distinct environment for different user spaces within a common host system using the same kernel.

Operating System Virtualization by Windows

The main virtualization features in Windows are provided by means of Hyper-V and other virtualization products.

• Hyper-V: Hyper-V is an application by Microsoft used for hardware virtualization in Windows Server and particular desktop editions of Windows. The software helps one to create and manage virtual machines that are independent computing units with their own operating systems and applications. Hyper-V is the layer of virtualization separating hardware and virtual machines.
• VMware Workstation Player: VMware Workstation Player is a virtualization product used to run several operating systems on one machine. The software supports many different host and guest operating systems, thus becoming a very flexible tool for both home and work use.

Other operating system virtualization technologies are Docker, Kubernetes, LXC/LXD, OpenVZ, FreeBSD Jails, and OpenStack.

Kinds of Disks in OS Virtualization

Effective data management is crucial in operating system virtualization. There are usually two main kinds of disks employed in virtual machines: private disks and shared disks.

1. Private Disk

A private disk can be used only by one virtual machine. No one else can access the disk; it works just like a regular hard drive of a non-virtualized system.

Private disks find application in operating systems, software programs, and confidential data. The main advantage of private disks is that other VMs do not have the ability to alter their contents, offering a higher level of security and isolation.

2. Shared Disk

Shared disks can be used by more than one VM at a time. Shared disks act as a common data source for situations where several VMs share data access requirements.

The application of shared disks is especially significant in clustered systems like database clusters, distributed file systems, and multi-node applications.

Advantages of Windows OS Virtualization

OS virtualization comes with a wide range of advantages that benefit both individuals and companies. Apart from lowering costs, OS virtualization ensures that operations run smoothly, making it a very important technology today. Some of the most notable advantages include:

Resource Optimization:

The main advantage of OS virtualization includes optimal utilization of resources. Unlike when each operating system requires its own set of hardware, several VMs can use the same hardware resource in an efficient manner.

Cost Savings:

Virtualization lowers costs due to the fact that less physical hardware is required. In this way, one saves on purchase costs, energy, and other fees such as those used in cooling. Maintenance costs are also lower.

Isolation and Security:

Every virtual machine is completely independent of other virtual machines, resulting in strong isolation. The compromise of one VM does not pose a threat to any other VM running on the same host computer. Isolation also helps in creating secure software development and testing environments.

Backup and Recovery Ease:

It is relatively easy to back up and restore virtual machines. Virtual machine images can be cloned, archived, backed up, and reused to improve system restoration and business continuity plans.

Scalability and Flexibility:

Organizations can use OS virtualization to scale up or scale down the resources on demand. New virtual machines can be set up easily, whereas existing ones can be expanded or shrunk based on organizational needs.

Software Development and Testing:

Virtualization offers extremely high flexibility for testing purposes. Various operating systems and software can be tested by running different VMs on the same computer.

Energy Savings:

Virtualization saves energy by placing multiple tasks on fewer servers. The reduced power needed for fewer servers makes the process more cost-effective while being environmentally friendly at the same time.

What Is Windows Virtualization-Based Security (VBS)?

As the name suggests, virtualization-based security is a combination of Hyper-V capabilities and the virtualization capabilities of the hardware platform to isolate some memory zones in the system. The purpose of isolating these memory zones is to provide protection to the most sensitive parts of the system's kernel and user mode.

Once isolated, these memory zones protect critical system processes, credentials, and other valuable system assets from being exploited by malicious users trying to execute their code and steal confidential data from the system.

Security Functions of Windows VBS

Windows VBS is a powerful security architecture in modern Windows systems that uses hardware virtualization to create a secure, isolated environment. It offers several powerful functions, which are as follows:

1. Hypervisor-Based Code Integrity (HVCI)

Code integrity in HVCI is checked before code execution, as it checks whether the drivers and binaries executed at the kernel mode level are signed properly. It prevents any unsigned or malicious code from loading in memory, thus lowering the risks of malware infection.

2. Windows Defender Credential Guard

Windows Defender Credential Guard helps protect credentials as they are stored in a secure virtual environment that makes it almost impossible for any malicious program to access passwords or any other credentials used to gain access.

3. Trusted Platform Modules (vTPMs)

VBS supports vTPMs, providing hardware-based security functions for shielded virtual machines. It offers an extra layer of data security for workloads run in virtual machines.

4. Shielded Virtual Machines

Windows Server provides extended functionality of shielded virtual machines to protect virtual machines when running, migrating, or storing any workloads, both on Windows and Linux OS.

5. Host Key Attestation

This feature was introduced in Windows Server 2019 and involves authenticating Hyper-V hosts with the use of asymmetric keys via the Host Guardian Service, making it easier to implement without needing AD trust relationships.

Virtualization-Based Security Requirements

In order to successfully implement VBS, there are particular hardware, firmware, and software requirements that need to be met:

Hardware Requirements:

• A 64-bit CPU with virtualization capabilities (Intel VT-x / AMD-V)
• Second-Level Address Translation support (SLAT)
• I/O virtualization (Intel VT-d / AMD-Vi)
• TPM 2.0 or higher

Firmware Requirements:

• Supposed for UEFI
• Secure Boot capability
• Memory protection options, such as the UEFI Memory Attributes Table
• Secure Memory Overwrite support

Software Requirements:

• Hyper-V installed
• HVCI driver support
• Windows Server operating system version supporting VBS

How to find your Windows Version?

For finding our Windows version, we have to follow the steps given below:

1. Firstly, go to the Windows search bar, enter “Control Panel” and open it.
2. In the Control Panel screen, there will be a number of icons/services available. Click on the icon “System”, as shown below.
   
3. In this window, under Windows Edition, you will find the version of your Windows. Moreover, you can find the version of your operating system and processor in System Type. The following picture depicts the system information of my computer.