What is the role of hypervisor in virtualization?

Let's delve into the technical details of the role of a hypervisor in virtualization.

What is Virtualization?

Virtualization is a technology that allows multiple operating systems (OS) or applications to run on a single physical machine. This is achieved by creating virtual instances of the hardware, allowing each virtualized system to operate as if it were running on its own dedicated physical hardware.

Role of Hypervisor:

A hypervisor, also known as a Virtual Machine Monitor (VMM), is a crucial component in the virtualization process. It sits between the hardware and the operating systems or virtual machines (VMs), managing the distribution of physical resources and ensuring isolation between the VMs.

1. Hardware Abstraction:

cssCopy code- The hypervisor abstracts the underlying physical hardware, presenting a virtualized view to the guest operating systems.
- It creates a layer of abstraction that allows multiple VMs to share the same physical resources without direct interference.

2. Resource Allocation:

vbnetCopy code- Hypervisors allocate physical resources like CPU, memory, disk space, and network bandwidth to each VM.
- Resource allocation is typically dynamic, allowing VMs to scale their resource usage based on demand.

3. Isolation:

cssCopy code- The hypervisor ensures isolation between different VMs, preventing one VM from affecting the operation of others.
- It acts as a barrier, providing a secure and independent environment for each VM.

4. Virtual Machine Creation and Management:

diffCopy code- The hypervisor facilitates the creation, deletion, and management of VMs.
- It is responsible for initializing VMs, loading their operating systems, and handling their shutdown or suspension.

5. Memory Management:

vbnetCopy code- The hypervisor manages memory allocation and ensures that each VM gets the required amount of RAM.
- Techniques like memory ballooning may be used to optimize memory usage across VMs.

6. CPU Scheduling:

sqlCopy code- The hypervisor schedules and allocates CPU resources to each VM, preventing one VM from monopolizing the CPU.
- It can implement features like time-slicing or priority-based scheduling.

7. I/O Device Virtualization:

cssCopy code- The hypervisor provides virtualized access to I/O devices, allowing multiple VMs to share physical devices.
- It handles the mapping of virtual devices to physical ones and ensures proper data flow.

8. Live Migration:

cssCopy code- Advanced hypervisors support live migration, allowing a VM to be moved from one physical host to another without disruption.
- This is useful for load balancing, maintenance, and minimizing downtime.

9. Security:

cssCopy code- Hypervisors play a crucial role in ensuring the security of virtualized environments, preventing unauthorized access and minimizing the risk of VM escape attacks.