Dr.M.Florence Dayana-Cloud Computing-Unit - 1.pdf

CORE COURSE VIII
CLOUD COMPUTING Credit: 5
UNIT -1 INTRODUCTION TO CLOUD
DEFINITION:
The cloud is a large group of interconnected computers. These computers can be
personal computers or network servers; they can be public or private. Cloud computing
is a technology that uses the internet and central remote servers to maintain data and
applications.
Eg: Yahoo email or Gmail etc.
THE VISION OF CLOUD COMPUTING:
The virtual provision of cloud computing is hardware, runtime environment and
resources for a user by paying money. As of these items can be used as long as the User,
no upfront commitment requirement. The whole computer device collection is turned
into a Utilities set that can be supplied and composed in hours rather than days together,
to deploy devices without Costs for maintenance.
A cloud computer's long-term vision is that IT services are traded without
technology and as utilities on an open market as barriers to the rules. We can hope in
the near future that it can be identified the solution that clearly satisfies our needs
entering our application on a global digital market services for cloud computing. This
market will make it possible to automate the process of discovery and integration with
its existing software systems. A digital cloud trading platform is available services will
also enable service providers to boost their revenue. A cloud service may also be a
competitor's customer service to meet its consumer commitments.
Company and personal data is accessible in structured formats everywhere,
which helps us to access and communicate easily on an even larger level. Cloud
computing's security and stability will continue to improve, making it even safer with a
wide variety of techniques. Instead of concentrating on what services and applications
they allow, we do not consider "cloud" to be the most relevant technology. The
combination of the wearable and the Bringing Your Own Device (BYOD) with cloud
technology with the Internet of Things (IoT) would become a common necessity in
person and working life such that cloud technology is overlooked as an enabler.
Figure 1.2. Cloud computing vision.

A CLOSER LOOK:
Cloud computing is useful in governments, enterprises, public and private
institutions and research organizations which make more effective and demand-driven
computing services systems. There seem to be a number of specific examples
demonstrating emerging applications of cloud computing in both established companies
and startups. Such cases are intended to illustrate the value proposition of viable cloud
computing solutions and the benefits businesses have gained from these services.
NewYork Times:
One of the most widely known examples of cloud computing commitment comes from
New York Times. The New York Times has collected a large number of high-resolution
scanned images of historical newspapers, ranging from 1851-1922. They want to
process this set of images into separate articles in PDF format. The New York Times
had the option to utilize 100 servers for 24 hours at the low standard cost of ten cent an
hour for every server. In the event that the New York times had bought even a solitary
server for this errand, the probable expense would have surpassed the $890 for simply
the hardware, and they likewise need to think about the expense of administration,
power and cooling Likewise, the handling would have assumed control more than a
quarter of a year with one server.
On the off chance that the New York Times had bought four servers, it would
have still taken almost a month of calculation time. The quick turnaround time and
endlessly lower cost emphatically represents the prevalent estimation of cloud services.
Washington Post:
The Washington Post were able to transform 17,481 pages of scanned document
images into a searchable database in just a day using Amazon EC2(Amazon Elastic
Compute Cloud- is a cloud computing platform). On March 19th at 10am, Hillary
Clinton’s official White House schedule from 1993-2001 was published to the public
as a large array of scanned photographs (in PDF format).
Washington Post programmer Peter Harkins utilized 200 Amazon EC2 instances
to conduct OCR (Optical Character Recognition) on the scanned files to create
searchable text – “I used 1,407 hours of virtual machine time with a total cost of
$144.62. We find it a positive proof of concept.
How all of the computing made possible? in same IT services on demand like
computing power, storage and providing an runtime environments for development of
an applications on pay-as-you go basis. Cloud computing not only provides an
opportunity for easily accessing of IT services as per demand, but also provides newly
ideas regarding IT Services and resources as am utilities. Figure 1.4 provides a bird’s-
eye view of cloud computing.

There are three deployment models for accessing the services of cloud
computing environment are public, private and hybrids clouds. The public cloud is
one of the most common deployment models in which computing services is offered by
third-party vendors that the consumer are able to access and purchase the resource from
the public cloud via the public internet. These can be free or on-demand, meaning that
consumers pay for their CPU cycles, storage or bandwidth per use. Public clouds will
save companies from the expensive procurement, Management and on-site maintenance
of hardware and application infrastructure — all management and maintenance of the
system is held to responsibility of the cloud service provider.
Public clouds can also be deployed faster than on-site infrastructures with a
platform almost constantly scalable. Although securityissues have been posed by public
cloud implementations, the public cloud could be as secure as the most efficiently
operated private cloud deployment when it is implemented correctly.
A private cloud is an essentially one organization's cloud service. In using a
private cloud, the advantages of cloud computing are experienced without sharing
resources with other organizations. There can be a private cloud within an organization,
or be controlled from a third party remotely, and accessed via the Internet (but it is not
shared with others, unlike a public cloud). Private cloud incorporates several of the
advantages of cloud computing — including elasticity, scalability and easy service
delivery — with the on-site control, security, and resource customization.
Many companies select private cloud over public cloud because private cloud is
a simpler way to satisfy their regulatory compliance requirements. Others prefer private
cloud because their workloads deal with confidential information, intellectual property,
and personally identifiable information (PII), medical records, financial data and other
sensitive data.
Hybrid cloud is an infrastructure that contains links between a user's cloud
(typically referred to as "private cloud") and a third-party cloud (typically referred to as
"public cloud"). Whilst the private and public areas of the hybrid cloud are linked, they
remain unique. This allows a hybrid cloud to simultaneously offer the advantages of
several implementation models. The sophistication of hybrid clouds is very different.
Some hybrid clouds, for example, only connect the on-site to public clouds. The
operations and application teams are responsible for all the difficulties inherent in the
two different infrastructures.

THE CLOUD COMPUTING REFERENCE MODEL
Fig 1: The Cloud Computing Reference Model
The NIST cloud computing reference architecture Fig 1 defines five major actors:
1. Cloud consumer
2. Cloud provider
3. Cloud carrier
4. Cloud auditor and
5. Cloud broker.
Each actor is an entity (a person or an organization) that participates in a transaction
or process and/or performs tasks in cloud computing.
Actors in Cloud Computing
Table 1: Actors in Cloud Computing
S.NO ACTOR DEFINITION
1. Cloud
Consumer
A person or organization that maintains a business
relationship with, and uses service from, Cloud Providers
2. Cloud
Provider
A person, organization, or entity responsible for making a
service available to interested parties.
3. Cloud
Auditor
A party that can conduct independent assessment of cloud
services, information system operations, performance and
security of the cloud implementation.
4. Cloud
Broker
An entity that manages the use, performance and delivery of
cloud services, and negotiates relationships between Cloud
Providers and Cloud Consumers.
5. Cloud
Carrier
An intermediary that provides connectivity and transport of
cloud services from Cloud Providers to Cloud Consumers

Interactions among the actors:
A cloud consumer may request cloud services from a cloud provider directly or via a
cloud broker.
A cloud auditor conducts independent audits and may contact the others to collect
necessary information.
Cloud carriers provide the connectivity and transport of cloud services from cloud
providers to cloud consumers.
A cloud provider participates in and arranges for two unique service level agreements
(SLAs), one with a cloud carrier (e.g. SLA2) and one with a cloud consumer (e.g.
SLA1).
A cloud provider arranges service level agreements (SLAs) with encrypted connections
to ensure the cloud services are consumed at a consistent level according to the
contractual obligations with the cloud consumers.
A cloud service, a cloud auditor conducts independent assessments of the operation and
security of the cloud service implementation. The audit may involve interactions with
both the Cloud Consumer and the Cloud Provider.
CHARACTERISTICS AND BENEFITS
1. Resources Pooling:
This means that the Cloud provider used a multi-leaner model to deliver the
computing resources to various customers. There are various allocated and reassigned
physical and virtual resources, which rely on customer demand. In general, the customer
has no control or information about the location of the resources provided, but can
choose location on a higher level of abstraction.
2. On-Demand Self-Service:
This is one of the main and useful advantages of Cloud Computing as the user
can track server uptimes, capability and network storage on an ongoing basis. The user
can also monitor computing functionalities with this feature.
3. Easy Maintenance:
The servers are managed easily and the downtime is small and there are no
downtime except in some cases. Cloud Computing offers an update every time that
increasingly enhances it. The updates are more system friendly and operate with patched
bugs faster than the older ones.
4. Large Network Access:
The user may use a device and an Internet connection to access the cloud data or
upload it to the cloud from anywhere. Such capabilities can be accessed across the
network and through the internet.
5. Availability:
The cloud capabilities can be changed and expanded according to the usage. This
review helps the consumer to buy additional cloud storage for a very small price, if
necessary.

6. Automatic System:
Cloud computing analyzes the data required automatically and supports a certain
service level of measuring capabilities. It is possible to track, manage and report the
usage. It provides both the host and the customer with accountability.
7. Economical:
It is a one-off investment since the company (host) is required to buy the storage,
which can be made available to many companies, which save the host from monthly or
annual costs. Only the amount spent on the basic maintenance and some additional costs
are much smaller.
8. Security:
Cloud Security is one of cloud computing's best features. It provides a snapshot
of the data stored so that even if one of the servers is damaged, the data cannot get lost.
The information is stored on the storage devices, which no other person can hack or use.
The service of storage is fast and reliable.
9. Pay as you go:
Users only have to pay for the service or the space in cloud computing. No hidden
or additional charge to be paid is liable to pay. The service is economical and space is
often allocated free of charge.
10. Measured Service:
Cloud Computing resources that the company uses to monitor and record. This
use of resources is analyzed by charge-per-use capabilities. This means that resource
use can be measured and reported by the service provider, either on the virtual server
instances running through the cloud. You will receive a models pay depending on the
manufacturing company's actual consumption.
CHALLENGES AHEAD:
All has advantages and challenges. We saw many Cloud features and it’s time to
identify the Cloud computing challenges with tips and techniques you can identify all
your own. Let's therefore start to explore cloud computing risk and challenges. Nearly
all companies are using cloud computing because companies need to store the data. The
companies generate and store a tremendous amount of data.
Thus, they face many security issues. Companies would include establishments
to streamline and optimize the process and to improve cloud computing management.
This is a list of all cloud computing threats and challenges:
1. Security & Privacy
2. Interoperability & Portability
3. Reliable and flexible
4. Cost
5. Downtime
6. Lack of resources
7. Dealing with Multi-Cloud Environments
8. Cloud Migration
9. Vendor Lock-In
10. Privacy and Legal issues

1. Security and Privacy of Cloud:
The cloud data store must be secure and confidential. The clients are so dependent on
the cloud provider. In other words, the cloud provider must take security measures
necessary to secure customer data. Securities are also the customer's liability because
they must have a good password, don't share the password with others, and update our
password on a regular basis. If the data are outside of the firewall, certain problems may
occur that the cloud provider can eliminate. Hacking and malware are also one of the
biggest problems because they can affect many customers. Data loss can result; the
encrypted file system and several other issues can be disrupted.
2. Interoperability and Portability:
Migration services into and out of the cloud shall be provided to the Customer. No bond
period should be allowed, as the customers can be hampered. The cloud will be capable
of supplying premises facilities. Remote access is one of the cloud obstacles, removing
the ability for the cloud provider to access the cloud from anywhere.
3. Reliable and Flexible:
Reliability and flexibility are indeed a difficult task for cloud customers, which can
eliminate leakage of the data provided to the cloud and provide customer trust
worthiness. To overcome this challenge, thirdparty services should be monitored and
the performance, robustness, and dependence of companies supervised.
4. Cost:
Cloud computing is affordable, but it can be sometimes expensive to change the cloud
to customer demand. In addition, it can hinder the small business by altering the cloud
as demand can sometimes cost more. Furthermore, it is sometimes costly to transfer
premises.
5. Downtime:
Downtime is the most popular cloud computing challenge as a platform free from
downtime is guaranteed by no cloud provider. Internet connection also plays an
important role, as it can be a problem if a company has a non-trust worthy internet
connection, because it faces downtime.
6. Lack of resources:
The cloud industry also faces a lack of resources and expertise, with many businesses
hoping to overcome it by hiring new, more experienced employees. These challenges
of the business but will also train existing employees to benefit the company. Currently,
many IT employees work to enhance cloud computing skills and it is difficult for the
chief executive because the employees are little qualified. It claims that employees with
exposure of the latest innovations and associated technology would be more important
in businesses.
7. Dealing with Multi-Cloud Environments:
Today not even a single cloud is operating with full According to the Right Scale report
revelation, almost 84 percent of enterprises adopt a multi cloud approaches mixed with
the public and private clouds. In addition, five different public and private clouds are
used by organizations.
8. Vendor lock-in:
The problem with vendor lock-in cloud computing includes clients being reliant (i.e.
locked in) on the implementation of a single Cloud provider and not switching to

another vendor without any significant costs, regulatory restrictions or technological
incompatibilities in the future.
The lock-up situation can be seen in apps for specific cloud platforms, such as
Amazon EC2, Microsoft Azure, that are not easily transferred to any other cloud
platform and that users are vulnerable to changes made by their providers to further
confirm the lenses of a software developer. In fact, the issue of lock-in arises when, for
example, a company decide to modify cloud providers but cannot move applications or
data across different cloud services, as the semantics of cloud providers' resources and
services do not correspond.
For these reasons, from the point of view of the company it is important to
maintain flexibility in changing providers according to business needs or even to
maintain in-house certain components which are less critical to safety due to risks. The
issue of supplier lock-in will prevent interoperability and portability between cloud
providers. It is the way for cloud providers and clients to become more competitive.
10. Privacy and Legal issues:
Apparently, the main problem regarding cloud privacy/data security is 'data
breach.' Infringement of data can be generically defined as loss of electronically
encrypted personal information. An infringement of the information could lead to a
multitude of losses both for the provider and for the customer; identity theft, debit/credit
card fraud for the customer, loss of credibility, future prosecutions and so on.
HISTORICAL DEVELOPMENTS
History of Cloud Computing:
Cloud computing is one of today's most breakthrough technology. Then there's a brief
cloud-computing history.
EARLY 1960S:
Computer scientist John McCarthy has a time allows the organization to use an
expensive mainframe at the same time. This machine is described as a major
contribution to Internet development, and as a leader in cloud computing.
IN 1969:
J.C.R. Licklider, responsible for the creation of the Advanced Research Projects
Agency (ARPANET), proposed the idea of "Intergalactic Computer Network" or

"Galactic Network" (a computer networking term similar to everyone around the world
and access programs and data from anywhere.
IN 1970:
Usage of tools such as VMware for operating system can be run in a separate
environment simultaneously. In a different operating system it was possible to operate
a completely different computer (virtual machine).
IN 1997:
Prof Ramnath Chellappa in Dallas in 1997 seems to be the first known definition of
"cloud computing," "a paradigm in which computing boundaries are defined solely on
economic alone."
IN 1999:
Salesforce.com was launched in 1999 as the pioneer of delivering client applications
through its simple website. The services firm has been able to provide applications via
the Inter mainstream software companies.
IN 2003:
This first public release of Xen, is a software system that enables multiple virtual guest
operating systems to be run simultaneous on a single machine, which also known as the
Virtual Machine Monitor (VMM) as a hypervisor.
IN 2006:
The Amazon cloud service was launched in 2006. First, its Elastic Compute Cloud (
EC2) allowed people to use their own cloud applications and to access computers.
Simple Storage Service (S3) was then released. This incorporated the user-as-you-go
model and has become the standard procedure for both users and the industry as a
whole.
IN 2013:
A total of £ 78 billion in the world’s market for public cloud services was increased by
18.5% in 2012, with IaaS as one of the fastest growing services on the market.
IN 2014:
Global business spending for cloud-related technology and services is estimated to be
£ 103.8 billion in 2014, up 20% from 2013 (Constellation Research). Figure gives an
analysis of the development of cloud computing distributed technologies.
When we track the historic developments, we review briefly five key technologies that
have played a significant role in cloud computing. They are distributed systems,
virtualization, Web 2.0, service orientation and utility computing.
DISTRIBUTED SYSTEM
Distributed System is a collection of autonomous computer systems that are physically
separated but are connected by a centralized computer network that is equipped with
distributed system software.

Example of Distributed System:
Any Social Media can have its Centralized Computer Network as its Headquarters and
computer systems that can be accessed by any user and using their services will be the
Autonomous Systems in the Distributed System Architecture.
Fig : Distributed System
 Distributed System Software: This Software enables computers to coordinate their
activities and to share the resources such as Hardware, Software, Data, etc.
 Database: It is used to store the processed data that are processed by each
Node/System of the Distributed systems that are connected to the Centralized
network.
Types of Distributed Systems
Two different types of distributed systems in the networking architecture.
Client/Server Systems
In client server systems, the client requests a resource and the server provides that
resource. A server may serve multiple clients at the same time while a client is in contact
with only one server. Both the client and server usually communicate via a computer
network and so they are a part of distributed systems.
Peer to Peer Systems
The peer to peer systems contains nodes that are equal participants in data sharing. All
the tasks are equally divided between all the nodes. The nodes interact with each other
as required as share resources. This is done with the help of a network.
Advantages of Distributed Systems
● Can easily share data with other nodes.
● More nodes can easily be added to the distributed system i.e. it can be scaled as
required.
● Failure of one node does not lead to the failure of the entire distributed system. Other
nodes can still communicate with each other.
● Resources like printers can be shared with multiple nodes rather than being restricted
to just one.

Disadvantages of Distributed Systems
● It is difficult to provide adequate security in distributed systems because the nodes as
well as the connections need to be secured.
● Some messages and data can be lost in the network while moving from one node to
another.
● The database connected to the distributed systems is quite complicated and difficult
to handle as compared to a single user system.
● Overloading may occur in the network if all the nodes of the distributed system try to
send data at once.
Applications Area of Distributed System
 Finance and Commerce: Amazon, eBay, Online Banking, E-Commerce websites.
 Information Society: Search Engines, Wikipedia, Social Networking, Cloud
Computing.
 Cloud Technologies: AWS, Salesforce, Microsoft Azure, SAP(System Application
and Products)
 Entertainment: Online Gaming, Music, Youtube.
 Healthcare: Online patient records, Health Informatics.
 Education: E-learning.
 Transport and logistics: GPS, Google Maps.
 Environment Management: Sensor technologies.
VIRTUALIZATION
Virtualization is technology that you can use to create virtual representations
of servers, storage, networks, and other physical machines.
The concept of virtualization was first devised in the 1960s. It was then
implemented by IBM to help split large mainframe machines into separate ‘virtual
machines’. The reason why this was done was to maximize their available mainframe
computers efficiency. One of the most important ideas behind cloud computing is
scalability, and the key technology that makes that possible is virtualization.
It was initially developed during the mainframe era. It involves using
specialized software to create a virtual or software-created version of a computing
resource rather than the actual version of the same resource.
With the help of Virtualization, multiple operating systems and applications
can run on the same machine and its same hardware at the same time, increasing the
utilization and flexibility of hardware.

 Host Machine: The machine on which the virtual machine is going to be built is
known as Host Machine.
 Guest Machine: The virtual machine is referred to as a Guest Machine.
Benefits of Virtualization
 More flexible and efficient allocation of resources.
 Enhance development productivity.
 It lowers the cost of IT infrastructure.
 Remote access and rapid scalability.
 High availability and disaster recovery.
 Pay peruse of the IT infrastructure on demand.
 Enables running multiple operating systems.
Characteristics of Virtualization
Virtualization is a fundamental technology that plays a pivotal role in the field of cloud
computing. It forms the cornerstone upon which the flexibility, scalability, and
efficiency of cloud services are built.
We will divide into the characteristics of virtualization in cloud computing, they are
 Increased Security: The ability to control the execution of a guest program in a
completely transparent manner opens new possibilities for delivering a secure,
controlled execution environment. All the operations of the guest programs are
generally performed against the virtual machine, which then translates and applies
them to the host programs.
 Managed Execution: In particular, sharing, aggregation, emulation and are the
most relevant features.
 Sharing: Virtualization allows the creation of a separate computing environment
within the same host.
 Aggregation: It is possible to share physical resources among several guests, but
virtualization also allows aggregation, which is the opposite process.
 Emulation: Emulation Cloud is an open application development environment
that helps customers and third-party developers create, test, and fine-tune
customized applications in a completely virtual environment.
Components of virtualized environments: Virtualization is a broad concept that
refers to the creation of a virtual version of something, whether hardware, software
environment, storage, or network. In a virtualized environment there are three major
components: guest, host, and virtualization layer.
Three major Components falls under this category in a virtualized environment:

1. GUEST:
The guest represents the system component that interacts with the virtualization
layer rather than with the host, as would normally happen. Guests usually consist of
one or more virtual disk files, and a VM file. Virtual Machines are centrally managed
by a host application that sees and manages each virtual machine as a different
application.
2. HOST:
The host represents the original environment where the guest is supposed to be
managed. Each guest runs on the host using shared resources donated to it by the host.
The operating system, works as the host and manages the physical resource
management, and the device support.
3. VIRTUALIZATION LAYER:
The virtualization layer is responsible for recreating the same or a different
environment where the guest will operate. It is an additional abstraction layer between
a network and storage hardware, computing, and the application running on it. Usually
it helps to run a single operating system per machine which can be very inflexible
compared to the usage of virtualization.
The most intuitive and popular is Hardware Virtualization, which also
constitutes the original realization of the Virtualization Concept.
Here in Hardware Virtualization Guest is represented by a system image which
is comprised of an operating system and installed applications. These are installed on
top of virtual hardware that is controlled and managed by the virtualization layer, also
called the Virtual Machine Manager. The host is instead represented by the physical
hardware and in some cases the operating system, which defines the environment
where the virtual machine manager is running.
Virtualization and cloud computing
Virtualization plays an important role in cloud computing since it allows for
the appropriate degree of customization, security, isolation, and manageability that are
fundamental for delivering IT services on demand.
Virtualization technologies are primarily used to offer configurable computing
environments and storage. A virtual computer system is known as a “virtual machine”
(VM): a tightly isolated software container with an operating system and application
inside.
Each self-contained VM is completely independent. Putting multiple VMs on
a single computer enables several operating systems and applications to run on just
one physical server, or “host”. A thin layer of software called a hypervisor decouples
the virtual machines from the host and dynamically allocates computing resources to
each virtual machine as needed.

Taxonomy of Virtualization Techniques
Virtualization covers a wide range of emulation techniques that are applied to different
areas of computing.
A classification of these techniques helps us better understand their characteristics and
use. We can divide the execution virtualization techniques into two major categories
by considering the type of host they require.
 Process-level techniques are implemented on top of an existing operating system,
which has full control of the hardware.
 System-level techniques are implemented directly on hardware and do not
require - or require a minimum of support from - an existing operating system
Execution virtualization:
 Execution virtualization includes all techniques that aim to emulate an execution
environment that is separate from the one hosting the virtualization layer.
 Execution virtualization can be implemented directly on top of the hardware by
the operating system, an application, or libraries dynamically or statically linked
to an application image.
Hardware-level virtualization:
 Hardware-level virtualization is a virtualization technique that provides an
abstract execution environment in terms of computer hardware on top of which
a guest operating system can be run.
 Hardware-level virtualization is also called system virtualization, which is the
representation of the hardware interface of a system.
PROS AND CONS OF CLOUD COMPUTING
Advantages
• Lower-Cost Computers for Users
• Improved Performance
• Lower IT Infrastructure Costs
• Fewer Maintenance Issues
• Lower Software Costs
• Instant Software Updates
• Increased Computing Power
• Unlimited Storage Capacity

• Increased Data Safety
• Improved Compatibility between Operating Systems
• Improved Document Format Compatibility
• Easier Group Collaboration
• Universal Access to Documents
• Latest Version Availability
• Removes the Tether to Specific Devices
Dis-Advantages
● Requires a Constant Internet Connection
● Doesn’t Work Well with Low-Speed Connections
● Can Be Slow
● Features Might Be Limited
● Stored Data Might Not Be Secure
● Problem will arise If Data loss occurs
Technology Examples
VMware
VMware is defined as a set of software and solutions that help convert the actual
computer, server, or pool of similar hardware into several virtual machines that may
be used for a variety of tasks. Their most popular virtualization applications are briefly
detailed below.
1-Desktop Editions
VMware Workstation – Is one of the longest running modern day virtualization
applications. It allows users to create multiple x86-based virtual machines on a single
physical machine. A wide number of guest operating systems such as Windows, Linux
and MAC OSX can then be installed on to these virtual machines.
VMware Fusion – This is similar to VMware Workstation, the only difference is that
VMware Fusion was designed for users of the Mac Intel hardware platform.
VMware Player – This application is a freeware application and is offered to users
who do not have a licence to run VMware Workstation or VMware Fusion. Unlike the
other two applications, VMware Player cannot create virtual machines, however it can
run them.
2-Server Editions
VMware ESX Server – This is an enterprise level virtualization product that is
offered by VMware. It does not require a host OS to be installed as it is installed
directly onto a server’s hardware. This is unlike the desktop editions which are
installed as applications from within their host OS. VMware ESX Server is much more
efficient than other virtualization technologies because it has lower system overheads
and interacts with its hardware directly.
VMware ESXi – This application is similar to the VMware ESX Server application.
The only difference is that it takes up less memory, because its Service Console is
replaced with a simpler interface.

VMware Server – This is VMwares free server virtualization application. It is an
application which needs to be installed onto a host OS that is either Window or Linux
based. Due to this fact it is not as efficient as the other VMware server editions, which
are installed directly on their hardware. However VMware Server does allow you to
create multiple virtual machines which can have a number of different guest operating
systems installed.

Dr.M.Florence Dayana-Cloud Computing-Unit - 1.pdf

More Related Content

Similar to Dr.M.Florence Dayana-Cloud Computing-Unit - 1.pdf (20)

More from Dr.Florence Dayana (20)

Recently uploaded (20)

Dr.M.Florence Dayana-Cloud Computing-Unit - 1.pdf