EXCEL ENGINEERING COLLEGE

(Autonomous)
INFORMATION TECHNOLOGY
Semester-VII
20IT702-CLOUD COMPUTING
Regulations 2020
Question Bank
UNIT IV HYPERVISORS AND VIRTUAL MACHINES
PART- A
Q.No Questions Marks CO BL
Define server virtualization. 2 CO4 R

Server virtualization is the process of dividing a physical server into

1 multiple unique and isolated virtual servers by means of a software
application. Each virtual server can run its own operating systems
independently.

List the types of server virtualization

• Hardware virtualization
• Hardware-assisted virtualization.
2
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• Hypervisor-based virtualization.
• Paravirtualization.
• OS-level virtualization.

What are the limitations of server virtualization?

• Machine turn up time. VMs run a fully-fledged OS.

3 • Low resource utilization. 2 R
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• Operational costs.
• Application packaging and deployment.

Relate full virtualization and Para virtualization.

Full Virtualization ParaVirtualization

It is the first generation of The interaction of the guest operating

4 2 U
software solutions for system with the hypervisor to improve CO4
server virtualization. performance and productivity is known as
paravirtualization.

Its performance is slow Its performance is high than full

than paravirtualization. virtualization.
5 Show the taxonomy of virtual machine. 2 R
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 Infer process virtual machines
A process virtual machine allows a single process to run as an
6 application on a host machine, providing a platform-independent 2 CO4 U
programming environment by masking the information of the underlying
hardware or operating system.

State system virtual machines.

These types of virtual machines gives us complete system platform and
7 gives the execution of the complete virtual operating system. Just like 2 CO4 R
virtual box, system virtual machine is providing an environment for an
OS to be installed completely.

What are hypervisors?

A hypervisor is a form of virtualization software used in Cloud hosting
to divide and allocate the resources on various pieces of hardware. The
program which provides partitioning, isolation, or abstraction is called a
8 virtualization hypervisor. 2 R
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The hypervisor is a hardware virtualization technique that allows
multiple guest operating systems (OS) to run on a single host system at
the same time. A hypervisor is sometimes also called a virtual machine
manager(VMM).

Define virtualization, virtual machine and virtual machine monitor.

Virtualization is technology that you can use to create virtual
representations of servers, storage, networks, and other physical
machines.
A virtual machine (VM) is a digital version of a physical computer.
9 2 R
Virtual machine software can run programs and operating systems, store CO4
data, connect to networks, and do other computing functions, and
requires maintenance such as updates and system monitoring.
A virtual machine monitor (VMM), also known as a hypervisor, is a
software, hardware, or firmware-based process that manages the creation
and operation of virtualized environments from the host system.

Compare process virtual machines and system virtual machines.

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A Process virtual machine, sometimes called an application virtual CO4
machine, runs as a normal application inside a host OS and supports a
 single process.
A System virtual machine provides a complete system platform which
supports the execution of a complete operating system
(OS), VirtualBox is one example.

Show emulation, simulation and virtualization

An emulator allows one type of OS to run applications for different OS.
A simulation, in this context, is software written to look and act like
11 another bit of software, perhaps simulating being on different hardware. 2 CO4 R
Virtualization is a technique that is used for having access to computing
resources and devices in completely function manner no matter what is
their physical layout or location.

State host servers

Cloud hosting is the ability to make applications and websites available
12 on the internet using the cloud. Cloud hosting pools computing 2
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resources from a network of virtual and physical servers, allowing for
greater scalability and flexibility to quickly make changes.

Define Disaster recovery?

The term cloud disaster recovery (cloud DR) refers to the strategies and
13 services enterprises apply for the purpose of backing up applications, 2 R
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resources, and data into a cloud environment. Cloud DR helps protect
corporate resources and ensure business continuity.

What is high availability?

High availability (HA) is the ability of a system to operate continuously
without failing for a designated period of time. HA works to ensure a
14 system meets an agreed-upon operational performance level. 2 R
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In information technology (IT), a widely held but difficult-to-achieve
standard of availability is known as five-nines availability, which means
the system or product is available 99.999% of the time.

How does a type 1 hypervisor differ from a type 2 hypervisor?

A type 1 hypervisor is a bare-metal hypervisor that runs directly on the
hardware, while a type 2 hypervisor runs on top of an operating system. 2
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This means that type 1 hypervisors have better performance and more
control over the hardware, while type 2 hypervisors are easier to install
and manage.

What happens if two or more VMs try to use the same hardware
resources at the same time?
If two or more VMs try to use the same hardware resources at the same time,
16 the hypervisor will arbitrate between them and determine which VM gets to 2 CO4 R
use the resources. This can lead to contention and performance issues, so it’s
important to try to avoid having VMs that are competing for the same
resources.

How does Cloud Computing relate to hypervisors?

17 2
Cloud computing is a model for delivering IT services in which resources are CO4 R
provided as a service over the Internet. A hypervisor is a type of software that
 allows multiple operating systems to run on a single physical server. In the
context of cloud computing, a hypervisor can be used to provide a cloud
service, such as a virtual private server.

What are some ways to create a new VM on a host?

There are a few ways to create a new VM on a host. One way is to use a
18 hypervisor, which is a piece of software that allows you to create and manage 2 CO4 R
virtual machines. Another way is to use a virtual machine manager, which is a
software application that helps you create and manage virtual machines.

Name the types of hypervisors?

19 Type 1 hypervisor is also known as bare metal hypervisor. 2 R

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Type 2 hypervisor also known as a hosted hypervisor

What kind of management tools are available for hypervisors?

There are a few different types of management tools available for hypervisors.
One type is a graphical user interface (GUI), which provides a visual way to
20 manage and monitor your hypervisor and virtual machines (VMs). Another 2 CO4 R
type is a command-line interface (CLI), which allows you to manage and
monitor your hypervisor and VMs using text-based commands. Finally, there
are also APIs, which allow you to programmatically manage and monitor your
hypervisor and VMs.

PART- B
Q.No Questions Marks CO BL
1 Explain the concepts of server virtualization with neat diagram.
Server Virtualization is most important part of Cloud Computing. So,
Talking about Cloud Computing, it is composed of two words, cloud and
computing. Cloud means Internet and computing means to solve problems
with help of computers. Computing is related to CPU & RAM in digital
world. Now Consider situation, You are using Mac OS on your machine
but particular application for your project can be operated only on
Windows. You can either buy new machine running windows or create 16 CO4 U
virtual environment in which windows can be installed and used. Second
option is better because of less cost and easy implementation. This scenario
is called Virtualization. In it, virtual CPU, RAM, NIC and other resources
are provided to OS which it needed to run. This resources is virtually
provided and controlled by an application called Hypervisor. The new OS
running on virtual hardware resources is collectively called Virtual
Machine (VM).
Now migrate this concept to data centers where lot of servers (machines
with fast CPU, large RAM and enormous storage) are available. Enterprise
owning data centre provide resources requested by customers as per their
need. Data centers have all resources and on user request, particular
amount of CPU, RAM, NIC and storage with preferred OS is provided to
users. This concept of virtualization in which services are requested and
provided over Internet is called Server
Virtualization.

To implement Server Virtualization, hypervisor is installed on server

which manages and allocates host hardware requirements to each virtual
machine. This hypervisor sits over server hardware and regulates resources
of each VM. A user can increase or decrease resources or can delete entire
VM as per his/her need. This servers with VM created on them is called
server virtualization and concept of controlling this VM by users through
internet is called Cloud Computing.
Advantages of Server Virtualization:
• Each server in server virtualization can be restarted separately
without affecting the operation of other virtual servers.
• Server virtualization lowers the cost of hardware by dividing a
single server into several virtual private servers.
• One of the major benefits of server virtualization is disaster
recovery. In server virtualization, data may be stored and retrieved
from any location and moved rapidly and simply from one server to
another.
 • It enables users to keep their private information in the data centers.
Disadvantages of Server Virtualization:
• The major drawback of server virtualization is that all websites that
are hosted by the server will cease to exist if the server goes offline.
• The effectiveness of virtualized environments cannot be measured.
• It consumes a significant amount of RAM.
• Setting it up and keeping it up are challenging.
• Virtualization is not supported for many essential databases and
apps.
2 Summarize about virtual machine and its working in cloud.
A Virtual Machine (VM) is a compute resource that uses software instead
of a physical computer to run programs and deploy apps. One or
more virtual “guest” machines run on a physical “host” machine. Each
virtual machine runs its own operating system and functions
separately from the other VMs, even when they are all running on the
same host. This means that, for example, a virtual MacOS virtual machine
can run on a physical PC.
Virtual machine technology is used for many use cases across on-premises
and cloud environments. More recently, public
cloud services are using virtual machines to provide virtual application
resources to multiple users at once, for even more cost efficient and
flexible compute.
VIRTUAL MACHINES USED
irtual machines (VMs) allow a business to run an operating system that
behaves like a completely separate computer in an app window
on a desktop. VMs may be deployed to accommodate different levels
of processing power needs, to run software that requires a different 16 CO4 U
operating system, or to test applications in a safe, sandboxed environment.
Virtual machines have historically been used for server virtualization,
which enables IT teams to consolidate their computing resources and
improve efficiency. Additionally, virtual machines can perform specific
tasks considered too risky to carry out in a host environment, such as
accessing virus-infected data or testing operating systems. Since the virtual
machine is separated from the rest of the system, the software inside the
virtual machine cannot tamper with the host computer.
VIRTUAL MACHINES WORK
The virtual machine runs as a process in an application window, similar to
any other application, on the operating system of the physical
machine. Key files that make up a virtual machine include a log file,
NVRAM setting file, virtual disk file and configuration file.
Advantages of virtual machines
Virtual machines are easy to manage and maintain, and they offer several
advantages over physical machines:
 • VMs can run multiple operating system environments on a
single physical computer, saving physical space, time and
management costs.
• Virtual machines support legacy applications, reducing the
cost of migrating to a new operating system. For
example, a Linux virtual machine running a distribution
of Linux as the guest operating system can exist on
a host server that is running a non-Linux operating system,
such as Windows.
• VMs can also provide integrated disaster recovery and
application provisioning options.
Disadvantages of virtual machines
While virtual machines have several advantages over physical machines,
there are also some potential disadvantages:
• Running multiple virtual machines on one physical machine
can result in unstable performance if infrastructure
requirements are not met.
• Virtual machines are less efficient and run slower than
a full physical computer. Most enterprises use a combination
of physical and virtual infrastructure to balance
the corresponding advantages and disadvantages.

3 Illustrate the concepts of hypervisor and its types.

A hypervisor is a form of virtualization software used in Cloud hosting to
divide and allocate the resources on various pieces of hardware. The
program which provides partitioning, isolation, or abstraction is called a
virtualization hypervisor. The hypervisor is a hardware virtualization
technique that allows multiple guest operating systems (OS) to run on a
single host system at the same time. A hypervisor is sometimes also called
a virtual machine manager(VMM).
Types of Hypervisor –
TYPE-1 Hypervisor:
The hypervisor runs directly on the underlying host system. It is also 16 CO4 U
known as a “Native Hypervisor” or “Bare metal hypervisor”. It does not
require any base server operating system. It has direct access to hardware
resources. Examples of Type 1 hypervisors include VMware ESXi, Citrix
XenServer, and Microsoft Hyper-V hypervisor.
Pros & Cons of Type-1 Hypervisor:
Pros: Such kinds of hypervisors are very efficient because they have
direct access to the physical hardware resources(like Cpu, Memory,
Network, and Physical storage). This causes the empowerment of the
security because there is nothing any kind of the third party resource so
that attacker couldn’t compromise with anything.
 Cons: One problem with Type-1 hypervisors is that they usually need a
dedicated separate machine to perform their operation and to instruct
different VMs and control the host hardware resources.
TYPE-2 Hypervisor:
A Host operating system runs on the underlying host system. It is also
known as ‘Hosted Hypervisor”. Such kind of hypervisors doesn’t run
directly over the underlying hardware rather they run as an application in
a Host system(physical machine). Basically, the software is installed on
an operating system. Hypervisor asks the operating system to make
hardware calls. An example of a Type 2 hypervisor includes VMware
Player or Parallels Desktop. Hosted hypervisors are often found on
endpoints like PCs. The type-2 hypervisor is very useful for engineers,
and security analysts (for checking malware, or malicious source code
and newly developed applications).
Pros & Cons of Type-2 Hypervisor:
Pros: Such kind of hypervisors allows quick and easy access to a guest
Operating System alongside the host machine running. These hypervisors
usually come with additional useful features for guest machines. Such
tools enhance the coordination between the host machine and the guest
machine.
Cons: Here there is no direct access to the physical hardware resources
so the efficiency of these hypervisors lags in performance as compared to
the type-1 hypervisors, and potential security risks are also there an
attacker can compromise the security weakness if there is access to the
host operating system so he can also access the guest operating system.
4 Extend the principles of VM Virtual box.
Oracle VM VirtualBox is a tool for virtualizing x86 and AMD64/Intel64
computing architecture, enabling users to deploy desktops, servers, and
operating systems as virtual machines. You can use this solution to deploy as
many virtual machines as the host architecture has the resources for.
Users can install this cross-platform virtualization tool on any Intel- or AMD-
powered computer. It runs on all major operating systems, including Windows,
Linux, Oracle Solaris, and macOS.
VirtualBox can extend the technical capabilities of any compatible computer,
enabling it to run multiple operating systems in different virtual machines at
once. For instance, a user can run Windows 11 and Ubuntu on their MacBook
Air without compromising their existing system configuration or applications.
VirtualBox allows any system to install and operate as many virtual machines
as its memory and disc space allow. Depending on the host system’s 16 CO4 U
configuration, one can use this solution to deploy anything from desktop-class
machines and small embedded systems to cloud environments and large
datacenter deployments.
VirtualBox is leveraged by IT administrators, software developers,
numerous other technical professionals, and general end-users for multiple
purposes. For instance, developers can create software for different platforms
on the same machine, while testers can use it to build virtual networks for
software testing.
VirtualBox can be downloaded and used for free by personal users under the
GNU General Public License. However, commercial users must purchase
the VirtualBox Extension Pack Enterprise commercial license for business
use. One perpetual VirtualBox Enterprise socket costs $1,220, while 100 units
of endless, named user plus sockets are priced at $6,100. Oracle also offers a
yearly Enterprise license at $50 per user.
The Enterprise license comes with improved Extension Pack management, a
proprietary feature pack offered by Oracle. The Extension Pack is free for
personal use; however, users must purchase a license for commercial
deployment. The Extension Pack unlocks remote desktop protocol (RDP)
support, USB 2.0 and USB 3.0 device support, disk encryption, and NVMe
and PXE boot for Intel systems.
Finally, users can leverage Guest Additions to expand VirtualBox functionality
even further. This module adds enhanced video support, mouse pointer
integration, host/guest shared folders and generic communication channels,
time synchronization, seamless windows, automated logon, and a shared
clipboard.

VIRTUALBOX WORK
Oracle VM VirtualBox is a powerful multi-platform virtualization engine
designed for deployment on desktop or server hardware. VirtualBox is
supported by all major operating systems, including Windows, popular Linux
kernels, macOS, and Oracle Solaris.
Operation
VirtualBox works by extending the capability of the existing operating system,
allowing it to run virtual machines without any changes to hardware or
software configuration. The operating system on which VirtualBox is installed
is called the host, while the operating systems running within VirtualBox are
known as guests. Once a guest operating system is deployed and correctly
configured, no limitations would set it apart from a machine for regular end-
users.
Simply put, a guest is an operating system running as a virtual machine. It is a
‘system within a system’ and can consist of any well-known or niche operating
system. However, users would need a separate licensed copy to run the virtual
machine legally for operating systems that require a license, such as Windows
and macOS.
A VirtualBox host may accommodate as many guest systems as its hardware
allows without sacrificing the resources required to run the host. Individual
guest instances may be launched, terminated, and paused using the VirtualBox
GUI or the command-line tool. The command-line option enables VMs to be
deployed on servers without GUI support, making VirtualBox a highly flexible
solution. These virtual machines can connect to a network when configured
correctly and operate as regular machines.
A typical VirtualBox deployment includes the following components:
• A hypervisor for the host system.
• A software development kit (SDK) and an application programming
interface (API) for administering guest VM operations.
• A command-line tool for local guest management.
• A web service that enables users to manage guests remotely.
• A wizard-style tool for guest management.
• A console that displays guest applications on the host.
• A remote desktop protocol (RDP) server enables users to access guests
using a remote client.
Administrators can deploy guest systems using ISO images or
VHD/VDI/VMDK images on the VirtualBox host platform. Deploying guests
using an ISO image enables guest operating systems to be installed normally
but as a VM. Conversely, VHD/VDI/VMDK images would allow
administrators to quickly deploy virtual appliances without installing an
operating system on the guest system. TurnKey Linux is a valuable resource
for finding virtual appliances for VirtualBox.
VirtualBox is modular, which allows it to provide a similar set of features
regardless of the host platform. Additionally, virtual machines and disk images
generated on any host will be compatible with other supported hosts. Also, any
user who learns to manage guest machines on a specific host would be able to
manage guests on different host systems as well.
Finally, some systems allow users to enable AMD-V or Intel VT-x hardware
virtualization extensions at the BIOS level. Deploying VirtualBox on such
systems can lead to even better guest operability.
MECHANISM
Intel x86 architecture features four tiers of storage protection known as ‘rings.’
These tiers go from level 0 (highest number of privileges) to level 3 (lowest
number of privileges).
These ‘ring levels’ are used by operating systems to safeguard vital system
memory from errors in programming that occur in user applications with fewer
rights. Level 0 permission grants applications access to real processor
resources like page tables, registers, and service interrupts. On most operating
systems, user programs are executed at level 3 while kernel services occur at
level 0.
VirtualBox executes one process on the host for each guest instance. All guest
user code is executed natively at level 3 as if running as a regular program on
the host system. This means user code operates at native speed when
performed in a guest VM environment.
VirtualBox protects the host from programming failures in guest instances by
preventing the guest kernel from running at level 0. Instead, the application is
executed at level 1 in systems without hardware virtualization support. This
support allows applications to run in a VT-x ring 0 contexts.
However, a problem might arise if the guest tries to run instructions that are
typically only authorized at level 0. This is addressed by VirtualBox’s Virtual
Machine Monitor (VMM), which scans level 1 code and either replaces
problematic code paths with direct hypervisor calls or runs the code in a secure
emulator environment.
Some operating systems may additionally use device drivers at level 1,
increasing the chances of a problem emerging due to the guest kernel code
relocation. For such guests, hardware virtualization is required.
Cases will also arise where the VMM cannot conclude the nature of the
relocated level 1 guest code’s activities. VirtualBox employs QEMU
emulation to get results in these situations. Examples of such exemptions
include BIOS code execution, real-mode operations earlier in the guest booting
process after the guest has turned off interrupts, or when a specific instruction
that is likely to need emulation is run.
Emulations are slow when compared to direct guest code execution. To
address this, the VirtualBox VMM assigns a unique code scanner for each
guest instance. This scanner replaces code paths with direct hypervisor calls to
make VM operations more efficient and precise.
Finally, the VMM constantly makes efforts to minimize future disruptions and
discover less resource-hungry methods to fulfill code streams. To do so, it will
conduct an in-depth analysis of the cause of every guest fault that occurs. This
enables VirtualBox to perform more efficiently than a typical code recompiler
or emulator.
5 Interpret the types of server virtualization.
Types of Server virtualization :
1. Hypervisor –
A Hypervisor or VMM(virtual machine monitor) is a layer that exists
between the operating system and hardware. It provides the necessary
services and features for the smooth running of multiple operating
systems.
It identifies traps, responds to privileged CPU instructions, and handles
queuing, dispatching, and returning the hardware requests. A host
operating system also runs on top of the hypervisor to administer and
manage the virtual machines.
2. Para Virtualization –
It is based on Hypervisor. Much of the emulation and trapping overhead
in software implemented virtualization is handled in this model. The
guest operating system is modified and recompiled before installation
into the virtual machine.
Due to the modification in the Guest operating system, performance is
enhanced as the modified guest operating system communicates directly
with the hypervisor and emulation overhead is removed. .

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3. Full
Virtualization –
It is very much similar to Paravirtualization. It can emulate the
underlying hardware when necessary. The hypervisor traps the machine
operations used by the operating system to perform I/O or modify the
system status. After trapping, these operations are emulated in software
and the status codes are returned very much consistent with what the real
hardware would deliver. This is why an unmodified operating system is
able to run on top of the
hypervisor.

4. Hardware-Assisted Virtualization –
 It is similar to Full Virtualization and Paravirtualization in terms of
operation except that it requires hardware support. Much of the
hypervisor overhead due to trapping and emulating I/O operations and
status instructions executed within a guest OS is dealt with by relying on
the hardware extensions of the x86 architecture.
Unmodified OS can be run as the hardware support for virtualization
would be used to handle hardware access requests, privileged and
protected operations, and to communicate with the virtual machine.
5. Kernel level Virtualization –
Instead of using a hypervisor, it runs a separate version of the Linux
kernel and sees the associated virtual machine as a user-space process on
the physical host. This makes it easy to run multiple virtual machines on
a single host. A device driver is used for communication between the
main Linux kernel and the virtual machine.
Processor support is required for virtualization ( Intel VT or AMD – v).
A slightly modified QEMU process is used as the display and execution
containers for the virtual machines. In many ways, kernel-level
virtualization is a specialized form of server virtualization.

6 Summarize the types of virtual machine.

Types of Virtual Machines :
1. System Virtual Machine: These types of virtual machines gives us
complete system platform and gives the execution of the complete virtual
operating system. Just like virtual box, system virtual machine is
providing an environment for an OS to be installed completely. We can
see in below image that our hardware of Real Machine is being
distributed between two simulated operating systems by Virtual machine
monitor. And then some programs, processes are going on in that
distributed hardware of simulated machines separately.

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 2. Process Virtual Machine : While process virtual machines, unlike
system virtual machine, does not provide us with the facility to install the
virtual operating system completely. Rather it creates virtual environment
of that OS while using some app or program and this environment will be
destroyed as soon as we exit from that app. Like in below image, there are
some apps running on main OS as well some virtual machines are created
to run other apps. This shows that as those programs required different OS,
process virtual machine provided them with that for the time being those
programs are running. Example – Wine software in Linux helps to run
Windows
applications.

(Note:*Blooms Level (R – Remember, U – Understand, AP – Apply, AZ – Analyze, E – Evaluate,

C – Create)
PART A- Blooms Level : Remember, Understand, Apply
PART B- Blooms Level: Understand, Apply, Analyze, Evaluate(if possible)
Marks: 16 Marks, 8+8 Marks, 10+6 Marks)

Subject In charge Course Coordinator HOD IQAC

(Name & Signature) (Name & Signature)