Explain hypervisors and their types

4.B) Explain hypervisors and their types. – 7 Marks

Answer:-

• A hypervisor (also known as a virtual machine manager, or VMM) is a critical component of hardware virtualization.
• It creates a virtualized environment, or virtual machines (VMs), by emulating the hardware necessary to run guest operating systems (OS) on top of a physical system.
• The hypervisor allocates resources such as CPU, memory, and storage to these VMs and ensures isolation between them.

There are two main types of hypervisors:

1. Type I Hypervisor (Bare-metal Hypervisor)

• Type I hypervisor runs directly on the physical hardware (bare-metal) without the need for an underlying host operating system.
• Functionality: It directly interfaces with the hardware and manages guest operating systems by providing them with virtualized hardware resources.
• Advantages:
  • Better Performance: Since there is no host OS layer, Type I hypervisors typically offer better performance and efficiency.
  • Enhanced Security: With no host OS, there are fewer layers to manage and secure, reducing vulnerabilities.
• Examples: VMware ESXi, Microsoft Hyper-V, Xen.

2. Type II Hypervisor (Hosted Hypervisor)

• Type II hypervisor runs on top of a host operating system, which provides the necessary services and interfaces for virtualization.
• Functionality: It relies on the host OS to interact with the hardware and emulate virtual hardware for guest operating systems.
• Advantages:
  • Easier to Install and Manage: Type II hypervisors are often used for desktop or testing environments because they can be installed like regular software on a host OS.
  • Less Resource Intense: Ideal for environments where performance demands are not as critical.
• Examples: VMware Workstation, Oracle VirtualBox, Parallels Desktop.

Comparison of Type I and Type II Hypervisors: