This document discusses virtual machines. It begins with a brief history of virtual machines and an explanation of what a virtual machine is - a software program that exhibits the behavior of a separate computer. There are two main types of virtual machines: system virtual machines that mimic an entire computer system, and process virtual machines that run single applications in isolation. Some key uses and applications of virtual machines are also outlined, along with the main pros and cons which include improved flexibility but reduced performance compared to physical machines.

1. VIRTUAL MACHINE
Presented by : Zain Raza
Discipline : Information Technology
5th Semester

2. OUTLINE
 History of Virtual Machine
 Virtual Machine (VM) mean?
 Types
 Use of VM
 Virtual Machine Application
 Pros & Cons of VM

3. HISTORY OF VM
 VM is a family of IBM virtual machine operating
systems used on IBM mainframes System/370.
 The first version, released in 1972, was VM/370.
 This was a System/370 reimplementation of earlier
CP/CMS operating system.

4. VIRTUAL MACHINE MEAN?
• A virtual machine (VM) is a software program or
operating system that not only exhibits the behavior
of a separate computer, but is also capable of
performing tasks such as running applications and
programs like a separate computer.
• A virtual machine, usually known as a guest is
created within another computing environment
referred as a "host." Multiple virtual machines can
exist within a single host at one time.
• A virtual machine is also known as a guest.

5. VIRTUAL MACHINE CONCEPT :

6. SNAPSHOT OF VM

7. TYPES OF VIRTUAL MACHINE
There are two main types of virtual machines :
One, which is called a system virtual machine, is
used to mimic all the processes and components of
an actual computer.
The other, which is known as a process virtual
machine, is used to run only a single application
and disappears when that application is closed.

8. SYSTEM VIRTUAL MACHINES :
 It allow a person to use a single server as if it were many
different computers.
 Using system machines also allows a user to run multiple
operating systems on the same machine.
 This allows a user to run programs that are only available on
one type of operating system.
 It also makes it possible to test a program across multiple
platforms without switching machines.
 System virtual machines (also known as full
virtualization VMs) provide a complete substitute for the
targeted real machine and a level of functionality required for
the execution of a complete operating system.

9. PROCESS VIRTUAL MACHINES :
 They are used to run a single program in isolation from
the physical computer’s operating system.
 This allows a user to run a program that might otherwise
be incompatible with the normal operating system.
 Each process machine is created to run a specific
program and exists only while the program is running.
 Closing the program it is running will make a process
machine disappear, and opening that program again will
create a new virtual machine.

10. USES OF VIRTUAL MACHINE :
 Virtual machines allow user to run an multiple operating
system on his windows desktop.
 VM use to run different software on an operating system.
 By using VM we can try different new operating systems on
your O/S.
 By using VM you can try your new software or web apps or
even site design by just building virtual machines and running
the tests there.
 When you get ready to move from XP to Vista, you can use
VMWare to make a backup of your old system.

11. VIRTUAL MACHINE APPLICATIONS :
There are three major virtual machine applications that run
on all three major computer operating systems
(Windows, Mac OS, and Linux).
The three virtual machine applications are:
 Parallels
 VMware
 Qemu
 KVM
 Xen
 TeamViewer
 VirtualBox.

12. THE MAIN PROS & CONS OF VM :
Pros :
 You can run other programs in a VM that may not
necessarily be in the same OS as the host machine.
 Ability to run more than one OS simultaneously.
 You can install/reinstall/backup/move your guest OS
easily.
 You can manage allocation of resource (Memory, Hard
disk), and etc.

13. THE MAIN PROS & CONS OF VM :
Cons :
 Performance drop. Usually much slower due to
the workload on the system by running virtual
machines.
 Virtual machine is not that efficient as a real one
when accessing the hardware.