02 VMs Hosts and Hypervisors || Virtualization #host

Summary

This video explains the concept of virtualization by first discussing physical machines and their hardware components, like memory, CPU, and storage. It then introduces virtual machines (VMs) and hypervisors, highlighting how VMs run on a host system with a hypervisor, such as ESXi or Hyper-V, managing resources like CPU, memory, and storage. The hypervisor allows multiple virtual machines with independent operating systems to share the same physical hardware while controlling their access to resources, enabling efficient utilization of server hardware.

Takeaways

• 😀 A physical server comes with hardware components like memory, CPU, network interface cards, and storage capacity.
• 😀 To run applications on a physical server, an operating system is installed to control the hardware resources.
• 😀 The operating system manages how applications use hardware resources, such as memory and CPU.
• 😀 A virtual machine (VM) runs on a host that has a hypervisor installed instead of a regular operating system.
• 😀 A hypervisor allows multiple virtual machines, each with its own OS, to share the physical resources of a host system.
• 😀 The host still has physical hardware like memory, CPU, network adapters, and storage, but the hypervisor manages resource allocation to VMs.
• 😀 Hypervisors such as ESXi or Hyper-V interpose themselves between VMs and the physical hardware, enabling virtualization.
• 😀 Virtual machines can run different operating systems, such as Windows or Linux, on the same physical host.
• 😀 The hypervisor manages resource sharing between VMs, allocating physical CPU, memory, network, and storage resources.
• 😀 As more VMs are created on the host, they share the same physical resources, with the hypervisor controlling the access and distribution of these resources.

Q & A

What is the role of a physical server in this context?

A physical server is a hardware machine that provides the resources such as memory, CPU, network interface cards, and storage. It runs an operating system (OS) that manages and allocates these resources to the applications running on the server.

How does an operating system interact with hardware on a physical server?

On a physical server, the operating system acts as an intermediary between the applications and the hardware. It controls how much memory, CPU, and storage each application can access and manages the overall interaction with the physical hardware.

What is a host in the context of virtualization?

A host is a physical server that runs a hypervisor instead of a regular operating system. The host provides the hardware resources (memory, CPU, storage) to support multiple virtual machines (VMs) running on it.

What is a hypervisor, and how does it work?

A hypervisor is a piece of software that sits between the virtual machines and the physical hardware. It controls the allocation of resources from the physical host to each virtual machine, ensuring that they share the hardware efficiently and securely.

What is the key difference between a physical server and a host in virtualization?

A physical server runs an operating system that manages applications, while a host runs a hypervisor and manages virtual machines. The host enables multiple VMs to share the hardware resources of the physical server.

Can virtual machines run different operating systems on the same host?

Yes, virtual machines can run different operating systems (e.g., Windows, Linux) on the same host, as the hypervisor isolates each VM and provides its own virtualized resources.

How does a hypervisor control the resources for virtual machines?

The hypervisor controls how resources such as memory, CPU, storage, and network interfaces are allocated to each virtual machine. It ensures that the VMs share the physical resources of the host without conflicts, managing the performance and security of each VM.

What is meant by a virtual machine sharing physical resources with other VMs?

It means that all virtual machines on a host are running on the same physical hardware (memory, CPU, storage). While each VM has its own operating system, the resources are divided and managed by the hypervisor so that they can be shared efficiently across multiple VMs.

Why is the hypervisor called the 'magic sauce' of virtualization?

The hypervisor is called the 'magic sauce' because it is the key component that makes virtualization possible. It enables multiple virtual machines to run independently on the same physical hardware, sharing resources without direct access to the physical hardware itself.

What types of hypervisors are commonly used in virtualization?

Common hypervisors include VMware ESXi, Microsoft Hyper-V, and KVM. These hypervisors are responsible for managing the VMs and allocating resources from the physical host to the virtual machines.