Virtualization allows multiple operating systems to run on a single machine by creating virtual versions of hardware resources. There are three main types of virtualization: partial, full, and para. A hypervisor manages virtual machines and allocates resources to guest operating systems. Cloud computing delivers computing as an on-demand utility over the internet by sharing resources. It provides software, platforms and infrastructure as services across public, private, hybrid and community clouds. Big data refers to massive volumes of structured and unstructured data that is difficult to process using traditional methods and requires specialized technologies.
2. VIRTUALIZATION – What is it?
Virtualization refers to the creation of a virtual resource like server, desktop, operating
system, file storage or network.
The main goal of virtualization is to manage the workloads by radically reducing the
CPU resources while executing multiple instances of a system.
The most common form of virtualization is the operating system level virtualization. It
is possible to run multiple operating system on a single piece of hardware .
When a different operating system is operating on top of the primary operating system
by means of virtualization it is referred to as virtual machine.
3. What are the different kinds of Virtualization?
Partial Virtualization: First virtualization that was introduced. Partial virtualization
on the whole operating system cannot run on the virtual machine. It requires partial
access to the underlying hardware.
Full Virtualization: Provides a virtual machine environment that required complete
simulation of the hardware. In case of full virtualization the image of the virtual
system has access to the underlying hardware.
Para Virtualization: Para virtualization enables several different operating systems to
run on one set of hardware by effectively using hardware. The modification of the
operating system made by paravirtualization is to minimize the execution time
required in performing operations that are otherwise difficult to run in a virtual
environment. The modifications in the operating system are made by the
“hypervisor”.
4. LIMITATIONS OF PARTIAL VIRTUALIZATION
It is not backward compatible.
It can be hard to anticipate precisely which features have been used by the
application
If certain hardware features are not simulated then any hardware using those features
will fail.
5. LIMITATIONS OF FULL VIRTUALIZATION
All operations and executions were limited to the virtual machine itself.
Full virtualization was not possible for the X-86 platform.
Full virtualization cannot be used to alter the state of any other virtual machine, the control
program or the hardware.
Only machine instructions local to the virtual machine can be executed directly by the
hardware. Any machine instruction inserted externally to the system would not be executed
by the hardware, moreover causing an OS trap.
6. HYPERVISOR – What is it?
A hypervisor or Virtual Machine Monitor is a piece of computer software or
hardware that creates and runs a Virtual Machine.
A computer on which a hypervisor is running one or more virtual machines is
defined as a “host machine”.
Each virtual machine is called a “guest machine”
The hypervisor presents the guest operating system with a virtual operating
platform and manages the guest operating systems.
7. TYPES OF HYPERVISOR
Type – 1 (or native, bare metal) hypervisors run directly on the host’s hardware and
to manage guest operating systems.
The hypervisor works parallel to the kernel.
The guest operating-system runs on another level above the hypervisor.
Type – 2 (or hosted) hypervisors run on a conventional operating system
environment.
With the hypervisor layer as a distinct second software level, guest operating system
run on the third level above the hardware.
11. Why was CLOUD COMPUTING at all needed?
High performance computing utilizes the concept of parallel processing which
requires distributed system to achieve parallel processing.
Research has shown virtualization to be the root cause for the detrimental
performance when it comes to virtualization in High Performance Computing.
Virtualization in High Performance Computing was considered as a root cause
for CPU and I/O overhead.
Later on Amazon launched the “EC2 Cluster Compute Instances” which did a
promising work in leveraging virtualization in High Performance Computing.
12. What is CLOUD COMPUTING and how is it different from
DISTRIBUTED COMPUTING
Cloud computing is the delivery of computing as a service rather than a product whereby shared
resources, software and information are provided to computers and other devices as a utility over
a network.
Distributed computing is the concept of using a distributed system consisting of many self-
governed nodes to solve a very large problem.
Distributed computing achieves this by breaking the problem up to similar tasks and assigning
these tasks to individual nodes.
13. THE DIFFERENT LAYERS OF CLOUD AS A SERVICE
SaaS (Software as a Service) - the vendor supplies the
software product and interacts with the user through a front-
end portal or a web based application for example “Google
Docs”.
PaaS (Platform as a Service) - in PaaS the cloud providers
provides an API which can be used by an application
developer to create applications on the provider’s platform.
For example “Google App Engine”.
IaaS (Infrastructure as a Service) - Infrastructure as a
Service is a provision model in which an organization
outsources the equipment used to support operations,
including storage, hardware, servers and networking
components. The service provider owns the equipment and
is responsible for housing, running and maintaining it. The
client typically pays on a per-use basis. For example
“Amazon EC2 services”, “Penguin Computing” on
Demand. It is also called Hardware as a Service or “HaaS”.
14. DIFFERENT TYPES OF CLOUDS
PUBLIC CLOUD – is made available to the general public by a
service provider who hosts the cloud infrastructure. Generally,
public cloud providers like Amazon AWS, Microsoft and Google
own and operate the infrastructure and offer access over the
Internet.
PRIVATE CLOUD - is cloud infrastructure dedicated to a
particular organization. Private clouds allow businesses to host
applications in the cloud, while addressing concerns regarding
data security and control, which is often lacking in a public cloud
environment.
HYBRID CLOUD - are a composition of two or more clouds
(private, or public) that remain unique entities but are bound
together offering the advantages of multiple deployment models.
COMMUNITY CLOUD - is a is a multi-tenant cloud service
model that is shared among several or organizations and that is
governed, managed and secured commonly by all the participating
organizations or a third party managed service provider.
15. PROS & CONS OF USING CLOUD AS A SERVICE
PROS
Less Maintenance.
Improve Accessibility.
Better Scalability.
Elastic Services.
Cost Effective.
Faster Performance.
Collaboration Efficiency.
Synchronization of data across devices.
Easy to share data.
Backing up data.
CONS
Business Discontinuity.
Protection Inconsistency.
Supplier Lock-in.
Data Unreliability.
Hypervisor Isolation Failure.
Network Vulnerabilities.
Licensing issues of software.
Platform inconsistency.
16. BIG DATA – What is it ?
Big data describes massive volumes of both structured and unstructured data that
is difficult to process using traditional database and software techniques.
Big data has the potential to help companies improve operations and make faster.
Big data when used by vendors refers to the technology that an organization
requires to handle large amounts of data storage facilities.
The HDFS cluster consists of a single NameNode that manages the DataNode and
regulate access of file by clients.