Full virtualization and para-virtualization are two types of virtualization techniques used in cloud computing.
Full Virtualization: Full virtualization is a technique where a complete virtual machine is created that emulates the underlying physical hardware. In this technique, the guest operating system is not aware that it is running on a virtual machine and therefore, it does not need to be modified. The virtual machine monitors all the instructions that the guest operating system tries to execute and translates them into instructions that can be executed by the host operating system. This technique is used in hypervisors such as VMware and Hyper-V. The main advantage of full virtualization is that it provides complete isolation between virtual machines and the host operating system.
Para-virtualization: Para-virtualization is a technique where the guest operating system is modified to be aware that it is running on a virtual machine. In this technique, the guest operating system communicates directly with the hypervisor instead of the emulated hardware. This technique is used in hypervisors such as Xen and KVM. The main advantage of para-virtualization is that it provides better performance compared to full virtualization, as the guest operating system does not have to go through the virtual machine monitor to access the hardware.
The key differences between full virtualization and para-virtualization are:
- Guest operating system modification: In full virtualization, the guest operating system does not need to be modified, while in para-virtualization, the guest operating system needs to be modified to communicate directly with the hypervisor.
- Hardware emulation: In full virtualization, the hardware is emulated by the virtual machine monitor, while in para-virtualization, the hypervisor provides direct access to the underlying hardware.
- Performance: Para-virtualization generally provides better performance compared to full virtualization, as the guest operating system communicates directly with the hypervisor instead of going through an emulated hardware layer.
