Virtualization Basics

1. M Tech (CS) / MCA Cloud Computing
3: Virtualization
Prof Neeraj Bhargava
Vaibhav Khanna
Department of Computer Science
School of Engineering and Systems Sciences
Maharishi Dayanand Saraswati University Ajmer

2. Virtualization
• Virtualization is the process of creating a virtual version
of an operating system, computer, application, or any
computing resource. Partitioning a hard drive is also a
virtualization. The term is virtualization as the users or
applications can communicate with the virtual
resources just like these would with logical resources.
Using this process, multiple operating systems can run
on a system. The logical view of resources makes it
easier to enhance the performance of resources. The
key benefit of virtualization is that it makes your
infrastructure more efficient. The performance,
availability of resources, and automation becomes
better.

3. Virtualization
• Virtualization is essentially a technology that allows
creation of different computing environments. These
environments are called virtual because they simulate
the interface that is expected by a guest.
• Virtualization technologies are also used to replicate
runtime environments for programs. Applications in
the case of process virtual machines (which include the
foundation of technologies such as Java or .NET),
instead of being executed by the operating system, are
run by a specific program called a virtual machine. This
technique allows isolating the execution of applications
and providing a finer control on the resource they
access.

4. Flavors of Virtualization
AggregationSharing Emulation Isolation Virtualization
Physical
Resources
Virtual
Resources

5. Virtualization Layer
Virtual Hardware Virtual NetworkingVirtual Storage
Software Emulation
Host Physical Hardware Physical Storage Physical Networking
Guest ApplicationsApplicationsVirtual Image

6. Storage Virtualization
• This involves the process of combining physical storage
devices into one virtualized storage environment. This
technology helps in the separation of physical storage
systems from virtual storage partitions. It is extremely
helpful for administrators to have extended control
over the resources and in turn, for the storage
allocation across users and projects. Migrating data
from one storage device to another can also be done
seamlessly, without the end users being impacted. This
technology is often used parallel with server
virtualization to reduce costs and for easier
implementation.

7. • The conversion of a physical system to a virtual
system is termed as Hardware Virtualization. The
Virtual Machine performs just like a physical
machine. The software and applications remain
on the physical system. The virtual image of the
software and applications is what is installed on
the virtual server and accessed by the virtual
machine. This is the most commonly used type of
virtualization owing to the ease of upgrades, cost
factor, and enhanced usage.
Hardware Virtualization

8. • In this type of virtualization, the operating system
of a desktop system is moved to a virtual
environment. So, the while the system is your
physical one, the operating system is hosted on a
virtual server, located somewhere else. The
advantage of moving the operating system to the
virtual server is that the copies of the same
operating system can be used by multiple users.
You would require a Virtual Machine Manager for
this model to work. This technology definitely
saves cost on the extra systems and operating
systems.
Operating system Virtualization

9. Operative Systems
ExecutionStack
Hardware - level
Virtualization
Hardware
Programming Languages
Applications
OS- level Virtualization
Programming Language
level Virtualization
Application - level
Virtualization

10. Virtualization vs Cloud Computing
• A popular IT myth is that Virtualization and Cloud
Computing are the same and that the terms can be
used interchangeably. But the fact is that though there
are similarities between the two technologies, both are
different in application and use. The primary difference
being that virtualization is a technology to create
virtual data and cloud computing is a service offering
this virtual data. Virtualization technology can be called
as the foundational unit for cloud computing. To
explain better, if cloud computing is the service,
virtualization is an element of the infrastructure
promoting cloud.

11. Virtualization vs Cloud Computing
• Both the technologies are used to maximize the
usage of computing resources. They work
towards increasing the performance and
efficiency and also reduce the costs involved. To
decide whether virtualization or cloud is best for
your business, you need to analyze your business
requirements. On the cost front, for
virtualization, the initial cost involved is more but
operational expenditure is lesser. While, for
cloud, initial cost is less but as users and demand
for resources increase, the operational
expenditure also increases.

12. Multi Tenancy
• Multi-tenancy is an important aspect in the functioning of
cloud computing and virtualization enables it. When an
instance of a software or applications runs on a server and
serves multiple tenants (client-organizations), the principle
behind this model is termed as Multi tenancy. In the multi
tenancy architecture, the application or software has its
data and properties virtually partitioned, so that each user
has a custom virtual software or application to use. Each
user’s data is separated and not visible to the other users.
• An economical factor driving the importance of cloud is
that development and maintenance expenses would be
shared by the end users.

13. Resiliency
• The failover mechanism that distributes redundant IT and
computing resource implementations across different
physical locations is known as Resilient computing. This
process is important in cloud computing because if one of
the resource is down or unavailable, the next redundant
implementation takes over the roles. So that end user is not
impacted by the downtime. The failover order can be
preconfigured. In cloud computing, resiliency can be those
redundant resources on the same cloud, but located at
geographically different location, or even on different
clouds.
• This technology helps increase the availability and trust on
the cloud applications and resources.

14. Cloud Ecosystem
• This is a term that describes the complex framework of
the interdependent resources that work in-sync to
enable the services of a cloud. In cloud computing, this
ecosystem involves the components such as software,
applications, and the infrastructure, as well as the
vendors, users, integrators, and any others who play a
role in enabling the services and functions of the cloud.
This collective group of the functions and capabilities
from the different organizations, platforms, and
services, together form the cloud ecosystem. There are
many layers within this computing model and these
enable the working of the dynamic environments
dependent on the model.

15. Virtualization
Execution
Environment
Storage
Network
….
Emulation
High-Level VM
Multiprogramming
Hardware-assisted
Virtualization
Process Level
System Level
Paravirtualization
Full Virtualization
How it is done? Technique Virtualization Model
Application
Programming
Language
Operating
System
Hardware
Partial Virtualization