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#let title = [
Unit 4: Virtual Layer
]
#let proverb = [
Knowledge not shared, remains unknown.
]
#set text(12pt)
#set page(
header: [
#box()[#proverb]
#h(1fr)
#box()[#title]
],
)
#align(center, text(20pt)[
*#title*
])
#show table.cell.where(y: 0): strong
= Basics
- Deployed on the physical layer.
- Specifies entities like virtualization software, resource poolsm and virtual resources.
- Abstracts the physical resources (compute, storage, network).
- Executing requests from control layer and forwarding them to the physical layer for execution.
= Introduction
_*Virtualization refers to the logical abstraction of physical resources such as compute, network and storage that enables a single hardware resource to support multiple concurrent instances of systems ot multiple hardware resources to support single instance of system.*_
- Allows us to make resources look larger or smaller than they actually are.
- Enables multitenant environment improving utilization of physical resources.
= Benefits of virtualization
1. Optimizes and consolidates utilization of IT resources.
2. Reduces cost and management complexity.
3. Reduces number of people required to maintain the system.
4. Reduces deployment time.
5. Increases flexibility.
= Overview
This layer is formed from virtualized compute, virtualized network, and virtualized storage. This enables 2 characteristics of cloud software:
1. Resource Pooling
2. Rapid elasticity
This layer also specifies the entities that operate in this layer:
1. Virtualization software
2. Resource Pools
3. Virtual resources
= Process and Operations
The key steps involved in making resources available to comsumers are:
1. Deploying virtualization software.
- Compute systems.
- Network devices.
- Storage devices.
2. Creating resource pools.
- Processing power and memory
- Network bandwidth
- Storage
3. Creating virtual resources.
- Virtual machines
- Virtual Networks
- LUNs
== Virtualization Software
The virtualization software performs the abstraction of the physical resources that ard deployed on computer systems, network devices, and storage devices.\
The key functions of virtualization software is:
1. Create resource pools
2. Create virtual resources.
== Resource Pools
A resource pool is an aggregation of computing resources such as processing power, memory, storage, and network bandwidth which provices an aggregated view of these resources to the control layer.
== Virtual resources
Virtualization software in collaboration with control layer creates virtual resources. Created by allocating physical resources from the resource pool. Share the pooled physical resources.
= Hypervisor
_*Hypervisor is a piece of software that is installed on a compute system and enables multiple OSs to run concurrently on a physical compute system.*_\
- The hypervisor along with the hypervisor management software (HMS) is the fundamental component for deploying software defined compute environments.\
- Abstracts the physical compute hardware to create multiple *virtual machines*.\
- The hypervisor provides standardized hardware resources, such as processor, memory, network, and disk to all virtual machines.\
Hypervisor has two main components:
1. Kernel
- Acts as kernel of any normal OS.
- Performs process creation, file system management, and process scheduling.
- Optimized for running multiple VMs concurrently.
2. Virtual Machine Manager (VMM)
- Anstracts hardware and appears as a physical compute system with all components required for running OSs and applications.
- Each VM is assigned a VMM that gets a share of the physical resources.
#pagebreak()
== Types of hypervisors
Categorized into two types:
#table(
columns: 2,
table.header[Bare Metal Hypervisor][Hosted Hypervisor],
[Installed directly on hardware.], [Installed as an application on host system.],
[Direct access to hardware resources.], [No direct access. All access through host OS.],
[More efficient.], [Less efficient.],
[Limited device drivers.], [Compatible with all devices supported by host OS.],
[Designed for data centers and cloud infrastructure.], [Used for development, testing and training.],
)
|
