Hardware virtualization, also known as server virtualization, is a technology that allows multiple virtual machines (VMs) to run on a single physical server by partitioning the physical server's resources. There are two main types of hardware virtualization techniques: full virtualization and para-virtualization.
- Full Virtualization: In full virtualization, the hypervisor or virtual machine monitor (VMM) runs directly on the host machine's hardware, which allows multiple VMs to run on a single physical server. The VMs run their own operating systems and applications, and each VM is isolated from the others, which ensures security and stability. Full virtualization is a popular technique because it is flexible and supports a wide range of guest operating systems.
Benefits of full virtualization:
- Isolation: Each VM is isolated from others, which provides a high level of security and stability.
- Resource allocation: Each VM can be allocated its own set of resources, such as CPU, memory, and storage, which allows for efficient resource utilization.
- Compatibility: Full virtualization supports a wide range of guest operating systems, which provides flexibility.
- Para-virtualization: In para-virtualization, the guest operating system is modified to work with the hypervisor or VMM, which allows for greater performance and efficiency compared to full virtualization. The guest operating system is aware that it is running on a virtual machine and communicates directly with the hypervisor or VMM to access resources. This results in lower overhead and improved performance compared to full virtualization.
Benefits of para-virtualization:
- Performance: Para-virtualization provides improved performance compared to full virtualization, as the guest operating system communicates directly with the hypervisor or VMM to access resources.
- Resource utilization: Para-virtualization allows for more efficient resource utilization compared to full virtualization, as the hypervisor or VMM can allocate resources more effectively.
- Flexibility: Para-virtualization supports a wide range of guest operating systems, which provides flexibility.
Overall, hardware virtualization techniques provide a flexible and efficient way to run multiple virtual machines on a single physical server, which improves resource utilization and reduces costs. Depending on the specific use case, full virtualization or para-virtualization may be the preferred technique, as each has its own benefits and limitations.
