What is Nested Virtualization?

Nested virtualization is a system in which one can run virtual machines inside other virtual machines, so one can create their own virtual environments. It works in such a way that it enables a hypervisor inside a virtual machine (VM) which itself is a hypervisor. A hypervisor is any computer software, hardware or firmware that creates and runs virtual machines. By virtually sharing resources such as memory, CPU and processing power, a hypervisor enables a host computer to support multiple guest machines. 

This technology is useful in a variety of scenarios, such as: 

1. Testing and development: Nested virtualization allows developers to test software on different operating systems without having to install them on their physical machines. They can create a virtual machine on their host machine, and then create another virtual machine inside it to test their software. 
2. Cloud computing: Cloud providers use nested virtualization to offer virtual machine instances to customers. Customers can then create their own virtual machines inside these instances. 
3. Security: Nested virtualization can help improve security by isolating applications and workloads in their own virtualized environments. This can prevent malicious code from spreading from one virtual machine to another.

Learn the steps to enable nested virtualization in Microsoft Azure.

What are the advantages of nested virtualization? 

Nested virtualization systems have various advantages over traditional on-site solutions. The following are some of the most prominent advantages: 

1. Resource efficiency: Nested virtualization allows multiple virtual machines to run on a single physical machine, thus reducing the hardware requirements and improving resource utilization. 
2. Flexibility: Nested virtualization enables the creation of complex virtual environments, which can be used for testing, development, and experimentation purposes. It also allows the use of different hypervisors and operating systems within a single virtual environment. 
3. Isolation: Nested virtualization provides better isolation between virtual machines, as each VM can run its own hypervisor. This can improve security and prevent potential conflicts between different VMs. 
4. Scalability: Nested virtualization allows for easy scaling of virtual environments, as additional VMs can be added without the need for additional physical hardware. 
5. Cost-effectiveness: By using nested virtualization, organizations can reduce their hardware and maintenance costs, as multiple virtual environments can be run on a single physical machine. 

When is nested virtualization used?  

Nested virtualization is typically used in the following scenarios: 

1. Testing and development: Nested virtualization is commonly used in testing and development environments to simulate complex and diverse IT architectures. Developers can use nested virtualization to create a multi-tier application architecture that can be tested in a single virtual environment. 
2. Cloud computing: Cloud providers use nested virtualization to offer virtualized environments to their customers with better isolation and security. This allows customers to create their own virtual machines within a cloud environment without worrying about other tenants running on the same physical machine. 
3. Training and education: Nested virtualization is commonly used in training and education environments to teach IT professionals about different virtualization technologies and how to configure and optimize virtual environments. 
4. Legacy application support: Nested virtualization can be used to run legacy applications that require older operating systems or hypervisors. This allows organizations to continue using these applications without having to maintain old physical hardware. 
5. Research and experimentation: Nested virtualization can be used in research and experimentation environments to create complex and diverse virtual environments that can be used to study and test different IT architectures and technologies.