Virtualization in Cloud

VIRTUALIZATION IN CLOUD COMPUTING:
1)WHAT IS VIRTUALIZATION?
->Virtualization refers to the creation of a virtual version of a
computer system, operating system, network or storage device. It
enables multiple operating systems to run on a single physical
machine, allowing for greater efficiency and flexibility in managing
and deploying resources.
->Virtualization technology allows for the creation of virtual
machines, which are essentially software-based emulations of a
physical machine. Each virtual machine runs its own operating system
and applications, but they share the resources of the physical host
machine. This allows multiple operating systems and applications to
coexist on a single physical server, which can reduce hardware costs,
simplify management, and improve resource utilization.
->In cloud computing, Virtualization facilitates the creation of virtual
machines and ensures the smooth functioning of multiple operating
systems. It also helps create a virtual ecosystem for server operating
systems and multiple storage devices, and it runs multiple operating
systems.
The terms Cloud Computing and Virtualization are now being used
interchangeably, and they are being unified quickly.
In simpler words, Cloud Computing in collaboration with
Virtualization ensures that the modern-day enterprise gets a more
cost-efficient way to run multiple operating systems using one
dedicated resource.
Virtualization in cloud computing is the process of creating a
virtual version of a physical computing resource such as a
server, network, storage device, or operating system. It
allows one physical computing resource to be split into

multiple virtual resources, each of which can be used for
different purposes. This allows multiple applications and
services to be run on the same physical server, which helps
to reduce hardware costs and improve scalability.
Virtualization also helps to improve security by isolating
applications and services on different virtual machines, so
that a security breach in one application or service doesn’t
affect the others.
Virtualization has a wide range of uses in
different areas. Some common use cases
include:
Server Consolidation: Virtualization allows multiple virtual servers to
be created on a single physical server. This can reduce the number of
physical servers required, which can save space, power, and cooling
costs.
Development and Testing: Virtualization can be used to create
isolated development and testing environments that are identical to
production environments. This can help developers and testers to
identify and fix issues before deploying changes to production
environments.
Disaster Recovery: Virtualization can be used to create replicas of
physical servers, which can be used as backups in case of a disaster.
In the event of a disaster, the virtual machines can be quickly and
easily started on another physical server, reducing downtime.

Cloud Computing: Virtualization is a key technology used in cloud
computing. Cloud providers use virtualization to create multiple
virtual servers on a single physical server, which allows them to offer
flexible and scalable cloud services.
Desktop Virtualization: Virtualization can be used to create virtual
desktops that are hosted on a central server. This can allow
employees to access their desktops and applications from anywhere,
on any device.
Virtualization is the creation of Virtual Version of something such as server,
desktop, storage device, operating system etc.
Thus, Virtualization is a technique which allows us to share a single physical
instance of a resource or an application among multiple customers and an
organization. Virtualization often creates many virtual resources from one physical
resource.
 Host Machine –
The machine on which virtual machine is going to create is known as Host
Machine.
 Guest Machine –
The virtual machines which are created on Host Machine is called Guest
Machine.
2)NEED OF VIRTUALIZATION Or Why
Virtualization in Cloud Computing?
->Virtualization is very important concept in cloud computing. In
cloud computing, a cloud vendor who will provide cloud services
have all physical resources like server, storage device, network
device etc. and these physical services are rented by cloud vendors
so that users will not worry about these physical services.
->But it is very costly to provide physical services per customer on
rent because firstly it becomes very costly, and users will not use the
fully services. So, this problem can be solved by Virtualization. It is
very cool approach for not only efficient use of Physical services but

also reduce costs of vendors. Thus, cloud vendor’s can vitalize their
single big server and provide smaller spec server to multiple
customer’s.
Cloud providers employ virtualization to create environments that
can fulfil each user’s unique needs. Cloud providers can spin up more
virtual instances to meet demand as more users come in.
Virtualization is an efficient way of managing computing resources,
maximizing utilization, and minimizing downtime.
3)Pros of Virtualization in Cloud Computing :
 Utilization of Hardware Efficiently –
With the help of Virtualization Hardware is Efficiently used

by user as well as Cloud Service Provider. In this the need of
Physical Hardware System for the User is decreases and this
results in less costly.In Service Provider point of View, they
will vitalize the Hardware using Hardware Virtualization
which decrease the Hardware requirement from Vendor side
which are provided to User is decreased. Before
Virtualization, Companies and organizations have to set up
their own Server which require extra space for placing them,
engineer’s to check its performance and require extra
hardware cost but with the help of Virtualization the all
these limitations are removed by Cloud vendor’s who
provide Physical Services without setting up any Physical
Hardware system.
 Availability increases with Virtualization –
One of the main benefit of Virtualization is that it provides
advance features which allow virtual instances to be
available all the times. It also has capability to move virtual
instance from one virtual Server another Server which is very
tedious and risky task in Server Based System. During
migration of Data from one server to another it ensures its
safety. Also, we can access information from any location
and any time from any device.
 Disaster Recovery is efficient and easy –
With the help of virtualization Data Recovery, Backup,
Duplication becomes very easy. In traditional method , if
somehow due to some disaster if Server system Damaged
then the surety of Data Recovery is very less. But with the
tools of Virtualization real time data backup recovery and
mirroring become easy task and provide surety of zero
percent data loss.
 Virtualization saves Energy –
Virtualization will help to save Energy because while moving
from physical Servers to Virtual Server’s, the number of
Server’s decreases due to this monthly power and cooling
cost decreases which will Save Money as well. As cooling

cost reduces it means carbon production by devices also
decreases which results in Fresh and pollution free
environment.
 Quick and Easy Set up –
In traditional methods Setting up physical system and
servers are very time-consuming. Firstly Purchase them in
bulk after that wait for shipment. When Shipment is done
then wait for Setting up and after that again spend time in
installing required software etc. Which will consume very
time. But with the help of virtualization the entire process is
done in very less time which results in productive setup.
 Cloud Migration becomes easy –
Most of the companies those who already have spent a lot in
the server have a doubt of Shifting to Cloud. But it is more
cost-effective to shift to cloud services because all the data
that is present in their server’s can be easily migrated into
the cloud server and save something from maintenance
charge, power consumption, cooling cost, cost to Server
Maintenance Engineer etc.
Cons of Virtualization:
 Data can be at Risk –
Working on virtual instances on shared resources means
that our data is hosted on third party resource which put’s
our data in vulnerable condition. Any hacker can attack on
our data or try to perform unauthorized access. Without
Security solution our data is in threaten situation.
 Learning New Infrastructure –
As Organization shifted from Servers to Cloud. They required
skilled staff who can work with cloud easily. Either they hire
new IT staff with relevant skill or provide training on that
skill which increase the cost of company.
 High Initial Investment –
It is true that Virtualization will reduce the cost of companies
but also it is truth that Cloud have high initial investment. It
provides numerous services which are not required and

when unskilled organization will try to set up in cloud they
purchase unnecessary services which are not even required
to them.




4)TYPES OF VERTUALIZATION:
Application Virtualization: This can be defined as the type of
Virtualization that enables the end-user of an application to have
remote access. This is achieved through a server. This server has all
personal information and other applicable characteristics required to
use the application. The server is accessible through the internet, and
it runs on a local workstation. With Application virtualization, an
enduser can run two different versions of the same software or the
same application. Application virtualization is offered through
packaged software or a hosted application.
Network Virtualization: This kind of virtualization can execute many
virtual networks, and each has a separate control and data plan. It
co-occurs on the top of a physical network, and it can be run by

parties who are not aware of one another. Network virtualization
creates virtual networks, and it also maintains a provision of virtual
networks. Through network virtualization, logical switches, firewalls,
routers, load balancers, and workload security management systems
can be created.
Desktop Virtualization: This can be defined as the type of
Virtualization that enables the operating system of end-users to be
remotely stored on a server or data center. It enables the users to
access their desktops remotely and do so by sitting in any
geographical location. They can also use different machines to
virtually access their desktops. With desktop virtualization, an end-
user can work on more than one operating systems basis the
business need of that individual. If the individual wants to work on an
operating system other than the Window Operating System, he can
use desktop virtualization. This provides the individual an
opportunity to work on two different operating systems. Therefore,
desktop virtualization delivers a host of benefits. It delivers
portability, user mobility, easy software management with patches
and updates.
Storage Virtualization: This type of Virtualization provides virtual
storage systems that facilitate storage management. It facilitates the
management of storage effectively and through multiple sources
accessed from a single repository. Storage virtualizations ensure
consistent performance and smooth performance. It also offers
continuous updates and patches on advanced functions. It also helps
cope with the changes that come up in the underlying storage
equipment.
Server Virtualization: This kind of Virtualization ensures masking of
servers. The main or the intended server is divided into many virtual
servers. Such servers keep changing their identity numbers and
processors to facilitate the masking process. This ensures that each
server can run its own operating systems in complete isolation.
Data virtualization: In Data virtualization, data is collected from
various sources and managed in a single place without knowing more

about the technical information like how data is collected, stored &
formatted then arranged that data logically so that its virtual view
can be accessed by its interested people and stakeholders, and users
through the various cloud services remotely.
It can be used to perform various functions as:
 Data-integration
 Service-oriented architecture data-services
 Business-integration
 Searching organizational data
VIRTUAL MACHINE:
A virtual machine is a software implementation of a computer
machine. It creates an isolated duplication of real computer and
allows us to perform operation as on real computer.
->VMs are used for installing one operating system in another
operating system on the same computer. For example-installing Linux
operating in windows operating system.
->It is also used for providing a runtime environment for executing a
language application in a platform independent way.
->By using hardware virtual machine, we can use hardware resources
effectively.
VIRTUAL MACHINES ARE SAPARATED INTO TWO MAJOR CLASSES:
i) A system virtual machine is fully virtualized to substitute for a
physical machine. A system platform supports the sharing of a host
computer’s physical resources between multiple virtual machines,
each running its own copy of the operating system. This virtualization
process relies on a hypervisor, which can run on bare hardware, such
as VMware ESXi, or on top of an operating system.
Examples of system virtual machine softwares:
i)VMware
ii)Virtual Box

iii)Parallels
ii) A process virtual machine allows a single process to run as an
application on a host machine, providing a platform-independent
programming environment by masking the information of the
underlying hardware or operating system. An example of a process
VM is the Java Virtual Machine, which enables any operating system
to run Java applications as if they were native to that system.

VIRTUAL MACHINE MONITOR(VMM) OR
HYPERVISORS:
A hypervisor is a piece of software or
firmware that creates and runs Virtual
Machine.
Different hypervisors are being used in the IT industry. Some of the
examples are VMware, Xen, Hyper-V, KVM, and OpenVZ.
->Hypervisors are the software tool that sits in between VMs and
physical infrastructure and provides the required virtual
infrastructure for VMs.
->The virtual infrastructure means virtual CPUs (vCPUs), virtual
memory, virtual NICs (vNICs), virtual storage, and virtual I/O devices.

INTERNAL ORGANISATION OF VMM:
There are three main modules, dispatcher, allocator, and interpreter,
coordinate their activity in order to emulate the underlying
hardware. The dispatcher constitutes the entry point of the monitor
and reroutes the instructions issued by the virtual machine instance
to one of the two other modules. The allocator is responsible for
deciding the system resources to be provided to the VM: whenever a
virtual machine tries to execute an instruction that results in
changing the machine resources associated with that VM, the
allocator is invoked by the dispatcher. The interpreter module
consists of interpreter routines. These are executed whenever a VM
executes a privileged instruction: a trap is triggered and the
corresponding routine is executed.
Before the hypervisors are introduced, there was a one-to-one
relationship between hardware and OSs. This type of computing
results in underutilized resources.
After the hypervisors are introduced, it became a one-to-many
relationship. With the help of hypervisors, many OSs can run and
share a single hardware.
Types of Hypervisors:

Hypervisors, are generally classified into two categories:
 Type 1 or bare metal hypervisors
 Type 2 or hosted hypervisors
TYPE-1
The Type 1 Hypervisors runs directly on the physical hardware of the
host machine. The Type 1 Hypervisor is also known as a bare-metal
hypervisor. There is no need to load an underlying operating system
to begin with this hypervisor type.
It contains a direct contact to the primary hardware. The Type 1
hypervisors are considered to be the most competent and
knowledgeable hypervisors accessible for enterprise computing.
Another name used for Type 1 Hypervisor includes native Hypervisor
or Bare Metal Hypervisor. Based upon its feature set, this Hypervisor
type is suitable for Datacentre environment. Its performance is high
and provides numerous other benefits to people.
Examples of Type 1 hypervisors include VMware ESXi, Citrix
XenServer, and Microsoft Hyper-V hypervisor.
TYPE:
A Type 2 hypervisor is usually installed on top of an accessible
operating system as discussed earlier. Another name used for Type
2 hypervisor is hosted hypervisor. This is because this hypervisor
type relies greatly on the pre-existing operating system of the host
machine for managing CPU calls, storage, network resources,
memory and more.
Basically, the software is installed on an operating system.
However, the major disadvantage of this approach is if the host OS
fails or crashes, it also results in crashing of VMs. So, it is

recommended to use type 2 hypervisors only on client systems
where efficiency is less critical.
Examples- VMWare Workstation and Oracle VirtualBox.

Properties of a Virtual Machine:
i) Virtual Hardware
Each VM has its own set of virtual hardware (e.g., RAM, CPU, NIC,
etc.) upon which an operating system and applications are loaded.
ii)Partitioning

Multiple applications and OSs can be supported within a single
physical system.
There is no overlap amongst memory as each Virtual Memory has its
own memory space.
iii)Isolation
VMs are completely isolated from host machine and other VMs. If a
VM crashes, all others are unaffected.
Data does not leak across VMs.
iv) Identical Environment
VMs can have a number of discrete identical execution environments
on a single computer, each of which runs an OS.
v) Compatibility
Virtual machines host their own guest operating systems and
applications, using all the components found in a physical computer
(motherboard, VGA card, network card controller, etc). This allows
VMs to be fully compatible with all standard x86 operating systems,
applications and device drivers. You can therefore run all the same
software that you would usually use on a standard x86 computer.
vi) Encapsulation
A virtual machine acts as a single software package that encapsulates
a complete set of hardware resources, an operating system, and all
its applications. This makes VMs incredibly portable and easy to
manage. You can move and copy a VM from one location to another
like any other software file or save it on any storage medium — from
storage area networks (SANs) to a common USB flash drive.
Emulators– Allow applications written for one hardware environment to run on a very
different hardware environment, such as a different type of CPU.

Difference between Full Virtualization and
Paravirtualization:
Full Virtualization: Full Virtualization was introduced by IBM in the year 1966. It
is the first software solution for server virtualization and uses binary translation and
direct approach techniques. In full virtualization, guest OS is completely isolated by
the virtual machine from the virtualization layer and hardware. Microsoft and
Parallels systems are examples of full virtualization.
Paravirtualization: Paravirtualization is the category of CPU virtualization which
uses hypercalls for operations to handle instructions at compile time. In
paravirtualization, guest OS is not completely isolated, but it is partially isolated by
the virtual machine from the virtualization layer and hardware. VMware and Xen are
some examples of paravirtualization.

DISCUSS THE INTERPRETATION AND BINARY
TRANSLATION UNDER THE VIRTUALIZATION FOR
CLOUD:

HLL VM:
HLL VM stands for High Level Language Virtual Machine, and it is a
type of virtual machine that is used in cloud computing to run high-
level programming languages, such as Java, Python, and Ruby, among
others.
In cloud computing, a virtual machine is a software abstraction of a
physical machine that runs an operating system and applications. A
virtual machine allows users to run multiple operating systems and
applications on a single physical machine, which makes it a popular
technology for cloud computing.
HLL VMs, such as the Java Virtual Machine (JVM), are designed to run
high-level programming languages that are compiled into bytecode.
The HLL VM translates the bytecode into machine language that can
be executed by the underlying hardware. This provides a layer of
abstraction between the high-level programming language and the
hardware, which makes it easier to write and deploy applications.
One of the benefits of using HLL VMs in cloud computing is that they
provide a consistent and reliable environment for running
applications, regardless of the underlying hardware. HLL VMs are also
portable, which means that applications can be moved between
different cloud providers without the need for significant code
changes.
In summary, HLL VMs are an important technology in cloud
computing that enable the running of high-level programming
languages in a virtualized environment, providing a layer of
abstraction between the application and the underlying hardware,
and allowing for portability and scalability of applications.

Hypervisor Comparison: KVM, Xen, VMware, Hyper-V
Xen:
Xen is a hypervisor that enables the simultaneous creation, execution and
management of multiple virtual machines on one physical computer.
Xen was developed by XenSource, which was purchased by Citrix Systems in
2007. Xen was first released in 2003. It is an open source hypervisor. It also
comes in an enterprise version.
Xen is primarily a bare-metal, type-1 hypervisor that can be directly installed on
computer hardware without the need for a host operating system. Because it’s a
type-1 hypervisor, Xen controls, monitors and manages the hardware, peripheral
and I/O resources directly. Guest virtual machines request Xen to provision any
resource and must install Xen virtual device drivers to access hardware
components. Xen supports multiple instances of the same or different operating
systems with native support for most operating systems, including Windows and
Linux. Moreover, Xen can be used on x86, IA-32 and ARM processor architecture.
--------------------------------------------------------------------------------
KVM:
Kernel-based Virtual Machine (KVM) is an open
source virtualization technology built into Linux®. Specifically, KVM
lets you turn Linux into a hypervisor that allows a host machine to
run multiple, isolated virtual environments called guests or virtual
machines (VMs)
KVM was first announced in 2006 and merged into the mainline
Linux kernel version a year later.
KVM converts Linux into a type-1 (bare-metal) hypervisor.
KVM is part of Linux. Linux is part of KVM.
KVM features:
Security
KVM uses a combination of security-enhanced Linux (SELinux) and secure
virtualization (sVirt) for enhanced VM security and isolation.

Storage:
KVM is able to use any storage supported by Linux, including some local disks
and network-attached storage (NAS).
Hardware support
KVM can use a wide variety of certified Linux-supported hardware platforms.
Because hardware vendors regularly contribute to kernel development, the latest
hardware features are often rapidly adopted in the Linux kernel.
Memory management
KVM inherits the memory management features of Linux, including non-uniform
memory access and kernel same-page merging
Performance and scalability
KVM inherits the performance of Linux, scaling to match demand load if the number
of guest machines and requests increases. KVM allows the most demanding
application workloads to be virtualized and is the basis for many enterprise
virtualization setups, such as datacentres and private clouds.
-----------------------------------------------------------------------------------------
VMware:
VMware, Inc. is an American cloud computing and virtualization technology company with
headquarters in Palo Alto, California.
What VMware is used for?
VMware Workstation is a line of Desktop Hypervisor products which lets users run
virtual machines, containers and Kubernetes clusters.
VMware Workstation is the most dependable, high-performing,
feature-rich virtualization platform for your Windows or Linux PC
(Figure 12 and Figure 13). It allows one physical PC to run multiple
operating systems at the same time. Actually, no restarting or hard-
drive partitioning is required. The software developers rely on
workstation to develop and test client-server, Web and cloud
applications in a replica of their production environments.
VMware's most notable products are its hypervisors. VMware became well known for its first type
2 hypervisor known as GSX.

Key Benefits of VMware
->Access anytime, anywhere
->Run applications in Windows, Linux and other systems at the same time without
restarting.
->Remotely access VMs running on VMware.
-> Run as a server to host applications for your team, department or anyone in your
organization
VIRTUAL BOX:
It is a powerful x86 and AMD64/Intel64 virtualization product for
enterprise as well as home use.
An extremely feature rich, high-performance product for enterprise
customers also, the only professional solution that is freely available
as Open Source Software under the terms of the GNU General Public
License (GPL) version 2. Presently, it runs on Windows, Linux,
Macintosh, and Solaris hosts and supports a large number of guest
OSs including but not limited to Windows (NT 4.0, 2000, XP, Server
2003, Vista, Windows 7, Windows 8, Windows 10), DOS/Windows
3.x, Linux (2.4, 2.6, 3.x and 4.x), Solaris and OpenSolaris, OS/2, and
OpenBSD.

Hyper-V:
Hyper-V is Microsoft's hardware virtualization product. It lets you create and run a software
version of a computer, called a virtual machine. Each virtual machine acts like a complete
computer, running an operating system and programs.
Hyper-V runs each virtual machine in its own isolated space, which means you can run more
than one virtual machine on the same hardware at the same time.
Hyper-V in Windows and Windows Server replaces older hardware virtualization products,
such as Microsoft Virtual PC, Microsoft Virtual Server, and Windows Virtual PC. Hyper-V
offers networking, performance, storage and security features not available in these older
products.
Hyper-V offers many features:
Computing environment - A Hyper-V virtual machine includes the same basic parts as a
physical computer, such as memory, processor, storage, and networking. All these parts have
features and options that you can configure different ways to meet different needs.
Disaster recovery and backup - For disaster recovery, Hyper-V Replica creates copies of
virtual machines, intended to be stored in another physical location, so you can restore the
virtual machine from the copy.
Optimization - Each supported guest operating system has a customized set of
services and drivers, called integration services, that make it easier to use the
operating system in a Hyper-V virtual machine.
Portability - Features such as live migration, storage migration, and import/export
make it easier to move or distribute a virtual machine.
Remote connectivity - Hyper-V includes Virtual Machine Connection, a remote
connection tool for use with both Windows and Linux. Unlike Remote Desktop, this
tool gives you console access, so you can see what's happening in the guest even
when the operating system isn't booted yet.
Security - Secure boot and shielded virtual machines help protect against malware
and other unauthorized access to a virtual machine and its data.

Virtualization in Cloud

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