🔴Before Virtualization
Previously, before virtualization, running more than one OS was possible through a process called dual boot. In this case, when computer is turned On, then user picks which OS to boot. But there is no option to use more than one OS at the same time. Also, partitioning for the dual boot does not allow both OS to access the same hardware resources. So, it was not possible to run multiple OS simultaneously on a single physical system and share the underlying hardware resources.
🔴After Virtualization
To solve this problem of partitioning, concept of virtualization came into picture. In virtualized environment, to achieve the necessary partition among the physical machine and its virtual machines, a virtualization layer is introduced. This virtualization layer is known as Hypervisor. With the help of hypervisor, one computer can run multiple OS simultaneously and there is no need to reboot the whole computer.
🔴Hardware Virtualization Architecture
- ✔Hardware virtualization uses bare metal architecture.
- ✔In this, a hypervisor is directly installed on the hardware.
- ✔Hypervisor communicates directly with the system hardware rather than relying on Host OS.
- ✔Examples - Hyper-V, ESXi, Citrix Xen server.
🔴3 types of Hardware Virtualization
1~ Full Virtualization
2~ Para Virtualization
3~ Emulation Virtualization
Full Virtualization
There is no need for any change in full virtualization to execute any application. Furthermore, the hardware architecture completely simulates, which is advantageous to the guest software. There is an environment, much like an operating system on a server. Administrators can merge the new and old systems for efficiency with the aid of full virtualization. As a result, it should work with the updated system.
Para Virtualization
The hardware does not simulate in paravirtualization, and the guest software operates its own isolated system. It is not essential to simulate the hardware, but it does make use of an API that changes the guest operating system. The hypervisor provides a variety of commands, known as hypercalls, that are transmitted from the operating system to the hypervisor. These hypercalls are also used to manage memory.
Emulation Virtualization
The virtual machine simulates hardware in emulation virtualization. The guest operating system does not need to be modified in this case. In this virtualization, computer hardware serves as architectural support for the creation and management of a completely virtualized VM.
🔴Wrapping Up
Hardware virtualization is rapidly developing and getting momentum in server systems. The primary idea behind hardware virtualization is to combine several small servers onto a large physical server so that it may be used more quickly and effectively.