Virtualization involves dividing the resources of a computer system into multiple execution environments. It works by inserting a thin virtualization layer that allows multiple operating systems to run concurrently on a single physical machine while sharing hardware resources. Virtualization provides significant benefits such as improved hardware utilization, simplified management, reduced costs, and improved fault tolerance.

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2.  Virtualization is a framework or methodology of dividing the
resources of a computer into multiple execution environments,
 Done by applying one or more concepts or technologies such
as:
 Hardware & software partitioning,
 Time-sharing,
 Partial or complete machine simulation,
 Emulation,
 Quality of service,
 And many others.
 “Virtualization is an abstraction layer that decouples the
physical hardware from the operating system to deliver greater
IT resource utilization & flexibility”.

3.  Virtualization technology enables multiple operating systems
and application „images‟ to share a single physical server. A
virtual server, or what is commonly known as a „virtual
machine‟, simulates the operations of your servers. This
enables an application to run on a machine as it would on a
physical server.

4.  Not a new concept
 1960‟s at IBM:
 M44/44X Project, the goal of which was being to evaluate the
then emerging time sharing system concepts.
 The architecture was based on virtual machines: the main
machine was an IBM 7044(M44) and each virtual machine was
an experimental image of the main machine(44X).
 IBM & MIT headed research through the years & eventually
developed the idea of a virtual Machine Monitor(VMM).

5.  The VMware virtualization platform is built on a business-
ready architecture.
 Use software such as VMware vSphere to transform or
“virtualized” the hardware resources of an x86-based
computer—including the CPU, RAM, hard disk and network
controller—to create a fully functional virtual machine that can
run its own operating system and applications just like a “real”
computer.
 Each virtual machine contains a complete system, eliminating
potential conflicts. VMware virtualization works by inserting a
thin layer of software directly on the computer hardware or on
a host operating system.

6.  This contains a virtual machine monitor or “hypervisor” that
allocates hardware resources dynamically and transparently.
 Multiple operating systems run concurrently on a single
physical computer and share hardware resources with each
other.
 By encapsulating an entire machine, including
CPU, memory, operating system, and network devices, a
virtual machine is completely compatible with all standard x86
operating systems, applications, and device drivers.
 We can safely run several operating systems and applications at
the same time on a single computer, with each having access to
the resources it needs when it needs them.

7. x86 privilege level The binary
architecture translation
without approach to x86
virtualization virtualization
The
Paravirtualization
approach to x86
Virtualization
The hardware assist
approach to x86
virtualization

8. Memory Virtualization

9. Device and I/O virtualization

10.  Modern computer systems are composed of various hardware
& software layers.
 Virtualization inserts a software layer(VMM) at different points
in this architecture, comes in three variants:
 Hardware-level virtualization,
 Operating system-level,
 High-level language virtual
machines.

11.  Virtualization layer sits right on top of the real hardware.
 Since the VM presents a version the real machine, all software
written for that hardware(x86) will run on that virtual machine.
 Original design from IBM in the 1960‟s

12.  Virtualization layer sit between the operating system and the
application programs that run on the operating system
 Virtual Machine runs applications, or sets of applications
written for the operating system but in a controlled
environment
 use host OS API
 FreeBSD jails act like this. What have we seen in lab that acts
like this?

13.  Virtualization layer sit between Application
the operating system and the
application programs that run Virtual Machine
on the operating system
VMM Applications
 Virtual Machine runs
applications, or sets of
applications written for the OS
operating system but in a
controlled environment
Real Machine
 use host OS API
 FreeBSD jails act like this.
What have we seen in lab that
acts like this?

14.  The virtualization layer sits
as an application program Java Byte Code
on top of the operating
JVM
system
 Can run any programs Applications
written for that virtual
machine abstraction
regardless of the operating OS
system hosting that virtual
machine
Real Machine

15.  It enables us to get the most out of our server hardware.
 It will allow us to set up redundant servers for better fault
tolerance.
 Management is simplified.
 We can partition applications on separate OSes for greater
reliability.
 Provisioning new servers for prototyping, testing and migration
is simplified.
 We can save energy.
 Virtual Desktop Infrastructure can save us a fortune on PCs

16.  SimOS
 Microsoft Virtual Server
 Mac-on-Linux
 Linux-VServer
 OpenVZ
 Microsoft Virtual PC

17.  Hardware companies have taken notice of virtualizations
growing popularity and advantages
 Intel (called Virtualization Technology or VT-X Vander pool)
and AMD (Pacifica) are releasing processors that have built in
software virtualization support that try to eliminate emulation
costs
 This support will allow Xen to support unmodified
unprivileged OS‟s (hello Windows support)

18.  Many organizations across Australia are starting to take
advantage of server virtualization to reduce power, cooling and
equipment costs, reduce server administration and
downtime, and gain a higher level of server redundancy.