VIrtualization and Types, Hypervisor and its types, Benefits

1. Unit 3
Virtualization concepts in Cloud Computing
By
Dr Mohammad Zunnun Khan

2. Virtualization in Cloud Computing
 Virtualization is the "creation of a virtual
(rather than actual) version of something,
such as a server, a desktop, a storage device,
an operating system or network resources".
 In other words, Virtualization is a technique,
which allows to share a single physical
instance of a resource or an application
among multiple customers and organizations.
 It does by assigning a logical name to a
physical storage and providing a pointer to
that physical resource when demanded.

3. Basic Concept of Virtualization
 Creation of a virtual machine over existing
operating system and hardware is known as
Hardware Virtualization.
 A Virtual machine provides an environment
that is logically separated from the
underlying hardware.
 Concept is not new. Multi Programming –
Each Process thinks it has complete control
on all of the resources.
◦ Virtual Memory
◦ CPU Sharing

4. Similarities and Differences with
Multiprogramming
 Multi Programming
◦ CPU is shared among processes
◦ Memory is shared using Page Tables.
◦ Process knows it is being managed- uses
system calls.
 Virtualization
◦ CPU is shared among OSs.
◦ Memory is shared using more level of
indirections. Multiple Page tables.
◦ OS may or may not know that it is being
managed.

5. Virtualization Architecture
 OS assumes complete control of the
underlying hardware.
 Virtualization architecture provides this
illusion through a hypervisor/VMM.
 Hypervisor/VMM is a software layer which:
◦ Allows multiple Guest OS (Virtual Machines) to run
simultaneously on a single physical host
◦ Provides hardware abstraction to the running Guest
OSs and efficiently multiplexes underlying hardware
resources.

7. Physical vs. Virtual Machine
image source: vmware.com

8. Physical
 Single OS
 H/W + S/W tightly coupled
 Application crashes affect all
 Resource under-utilization
Virtual Machine
 Machine view to OS is independent of
hardware
 Multiple OS (isolated apps)
 Safely multiplex resources across VMs

9. Types of Virtualization
 There are two main parts of machine
◦ Host Machine, on which the virtual machine is
going to create
◦ Guest Machine, on which user is going to
use virtual service.
 There are mainly 4 types of
virtualization
◦ Hardware Virtualization.
◦ Operating system Virtualization.
◦ Server Virtualization.
◦ Storage Virtualization.

10. Hardware Virtualization:
 When the virtual machine software or virtual
machine manager (VMM) is directly installed
on the hardware system is known as
hardware virtualization.
 The main job of hypervisor is to control and
monitoring the processor, memory and other
hardware resources.
 After virtualization of hardware system we
can install different operating system on it
and run different applications on those OS.

11.  Usage:
 Hardware virtualization is mainly done for
the server platforms, because controlling
virtual machines is much easier than
controlling a physical server.

12. Operating System Virtualization
 When the virtual machine software or
virtual machine manager (VMM) is
installed on the Host operating
system instead of directly on the
hardware system is known as operating
system virtualization.
 Usage:
 Operating System Virtualization is mainly
used for testing the applications on
different platforms of OS.

13. Server Virtualization:
 When the virtual machine software or
virtual machine manager (VMM) is directly
installed on the Server system is known
as server virtualization.
 Usage:
 Server virtualization is done because a
single physical server can be divided into
multiple servers on the demand basis and
for balancing the load.

14. Storage Virtualization:
 Storage virtualization is the process of
grouping the physical storage from
multiple network storage devices so that
it looks like a single storage device.
 Storage virtualization is also implemented
by using software applications.
 Usage:
 Storage virtualization is mainly done for
back-up and recovery purposes.

15. What is Hypervisor
 If you know what a private cloud is and you know the
infrastructure of it, you’ve probably heard about
hypervisor.
 It is the part of the private cloud that manages the virtual
machines, i.e. it is the part (program) that enables multiple
operating systems to share the same hardware.
 Each operating system could use all the hardware
(processor, memory) if no other operating system is on.
That is the maximum hardware available to one operating
system in the cloud.
 Nevertheless, the hypervisor is what controls and allocates
what portion of hardware resources each operating system
should get, in order every one o them to get what they
need and not to disrupt each other.

16. Types of Hypervisor
 There are two types of hypervisors
 Type 1 hypervisor: hypervisors run
directly on the system hardware – A “bare
metal” embedded hypervisor,
 Type 2 hypervisor: hypervisors run on a
host operating system that provides
virtualization services, such as I/O device
support and memory management.

18. Type 1 hypervisors:
1. VMware ESX and ESXi
 These hypervisors offer advanced features and scalability, but
require licensing, so the costs are higher.
 There are some lower-cost bundles that VMware offers and they can make
hypervisor technology more affordable for small infrastructures.
 VMware is the leader in the Type-1 hypervisors. Their vSphere/ESXi product
is available in a free edition and 5 commercial editions.
2. Microsoft Hyper-V
 The Microsoft hypervisor, Hyper-V doesn’t offer many of the advanced features
that VMware’s products provide.
However, with XenServer and vSphere, Hyper-V is one of the top 3 Type-1
hypervisors.
 It was first released with Windows Server, but now Hyper-V has been greatly
enhanced with Windows Server 2012 Hyper-V. Hyper-V is available in both a
free edition (with no GUI and no virtualization rights) and 4 commercial
editions – Foundations (OEM only), Essentials, Standard, and Datacenter.
Hyper-V

19. 3. Citrix XenServer
 It began as an open source project.
The core hypervisor technology is free, but like
VMware’s free ESXi, it has almost no advanced
features.
Xen is a type-1 bare-metal hypervisor. Just as Red
Hat Enterprise Virtualization uses KVM, Citrix uses
Xen in the commercial XenServer.
 Today, the Xen open source projects and community
are at Xen.org. Today, XenServer is a commercial
type-1 hypervisor solution from Citrix, offered in 4
editions. Confusingly, Citrix has also branded their
other proprietary solutions like XenApp and
XenDesktop with the Xen name.
4. Oracle VM
 The Oracle hypervisor is based on the open source
Xen.
However, if you need hypervisor support and product
updates, it will cost you.
Oracle VM lacks many of the advanced features found
in other bare-metal virtualization hypervisors.

20. Type 2 hypervisor
1. VMware Workstation/Fusion/Player
 VMware Player is a free virtualization hypervisor.
 It is intended to run only one virtual machine (VM) and does not allow creating VMs.
VMware Workstation is a more robust hypervisor with some advanced features, such as
record-and-replay and VM snapshot support.
 VMware Workstation has three major use cases:
 for running multiple different operating systems or versions of one OS on one desktop,
 for developers that need sandbox environments and snapshots, or
 for labs and demonstration purposes.
2. VMware Server
 VMware Server is a free, hosted virtualization hypervisor that’s very similar to the VMware
Workstation.
VMware has halted development on Server since 2009
3. Microsoft Virtual PC
 This is the latest Microsoft’s version of this hypervisor technology, Windows Virtual
PC and runs only on Windows 7 and supports only Windows operating systems running on
it.

21. 4. Oracle VM VirtualBox
 VirtualBox hypervisor technology provides
reasonable performance and features if you
want to virtualize on a budget. Despite being
a free, hosted product with a very small
footprint, VirtualBox shares many features
with VMware vSphere and Microsoft Hyper-V.
5. Red Hat Enterprise Virtualization
 Red Hat’s Kernel-based Virtual Machine (KVM)
has qualities of both a hosted and a bare-
metal virtualization hypervisor. It can turn the
Linux kernel itself into a hypervisor so the
VMs have direct access to the physical
hardware.

22. KVM
 This is a virtualization infrastructure for the
Linux kernel. It supports native virtualization
on processors with hardware virtualization
extensions.
 The open-source KVM (or Kernel-Based
Virtual Machine) is a Linux-based type-1
hypervisor that can be added to most Linux
operating systems including Ubuntu, Debian,
SUSE, and Red Hat Enterprise Linux, but
also Solaris, and Windows.
 .

23. Benefits of using Virtual Machines
 Instant provisioning - fast scalability
 Live Migration is possible
 Load balancing and consolidation in a
Data Center is possible.
 Low downtime for maintenance
 Virtual hardware supports legacy
operating systems efficiently
 Security and fault isolation

24. VM Migration

25. Load Balancing
Better Response time

26.  Consolidation -
Reduces number of Physical Machine req
uirement

27. References
 Amburst et al. “Above the Clouds: A
Berkeley view of cloud computing”
 David Chisnall. “The Definitive Guide to
XEN Hypervisor”.
 Prof. Purushottam Kulkarni, CSE, IITB, His
Presentation.
 Vmware “ www.vmware.com”
 Wikipedia and Internet.

28.  Thank You
 Any Questions?
Email me on zunnunkhan@gmail.com