this book is very useful for learning virtualization.

1. virtual machine (VM)

2. What is virtual machine (VM)
• A virtual machine (VM) is a software program or
operating system that not only exhibits the behavior of a se
parate 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.

3. What is virtual machine (VM)
• Virtual machines are becoming more common with the
evolution of virtualization technology. Virtual machines are o
ften created to perform certain tasks that are different than t
asks performed in a host environment.
• In the VM world, the operating system actually running o
n your computer is called the host and any operating syst
ems running inside VMs are called guests. It helps keep t
hings from getting too confusing.

4. Uses/Benefits of (VM)
• They are used for testing purposes, especially to perform
risky tasks such as running malicious software, testing o
perating systems or creating backups, and accessing ma
lware-infected data.
• A lightweight software known as hypervisor allocates the
computing resources (RAM, CPU power, memory, storag
e, etc.) of the server or host to each VM, keeping all of
them separate to avoid interference.
• The computer’s operating system and applications are
separated from its hardware so that each new virtual
machine can access the physical resources of the original
server, which are managed by the hypervisor.

5. Uses/Benefits of (VM)
Virtual machines allow you to run an operating system in an
app window on your desktop that behaves like a full,
separate computer.
You can use them play around with different operating
systems, run software your main operating system can’t,
and try out apps in a safe, sandboxed environment.
in a particular VM, the guest OS is stored on a virtual hard
drive—a big, multi-gigabyte file stored on your real hard
drive. The VM app presents this file the guest OS as a real
hard drive. This means you won’t have to mess around with
partitioning or doing anything else complicated with your
real hard drive.

6. Uses/Benefits of (VM)
VMs offer a number of serious uses. They allow you to
experiment with another OS without having to install it on
your physical hardware. For example, they are a great way
to mess around with Linux—or a new Linux distribution
and see if it feels right for you. When you’re done playing wi
th an OS, you can just delete the VM.

7. Advantages.
• There are no protection problems because each virtual machine is
completely isolated from all other virtual machines.
• Virtual machine can provide an instruction set architecture that
differs from real computers.
• Easy maintenance, availability and convenient recovery.

8. Disadvantages:
• When multiple virtual machines are simultaneously running on a host
computer, one virtual machine can be affected by other running
virtual machines, depending on the workload.
• Virtual machines are not as efficient as a real one when accessing
the hardware.

9. Setting Up a Virtual Machine
Once you’ve decided on a VM app and gotten it installed, setting up a
VM is actually pretty easy. We’re going to run through the basic process
in VirtualBox, but most apps handle creating a VM the same way.
1. Open up your VM app and click the button to create a new virtual
machine.

10. Setting Up a Virtual Machine
2. You’ll be guided through the process by a wizard that first
asks which OS you’ll be installing. If you type the name of the
OS in the “Name” box, the app will most likely automatically s
elect the type and version for the OS. If it doesn’t—or it gues
ses wrong—select those items yourself from the dropdown m
enus. When you’re done, click “Next.”

11. Setting Up a Virtual Machine
3. Based on the OS you plan to install, the wizard will preselect some
default settings for you, but you can change them over the screens that
follow. You’ll be asked how much memory to allocate to the VM. If you
want something other than the default, select it here. Otherwise, just click
“Next.” And don’t worry, you’ll be able to change this value later if you
need to.

12. Setting Up a Virtual Machine
4. The wizard will also create the virtual hard disk file to be us
ed by the VM. Unless you already have a virtual hard disk file
you want to use, just select the option to create a new one.

13. Setting Up a Virtual Machine
5.
You’ll also be asked whether to create a dynamically allocate
d or fixed size disk. With a dynamically allocated disk, you’ll s
et a maximum disk size, but the file will only grow to that size
as it needs to. With a fixed size disk, you’ll also set a size,
but the file created will be that large from its creation.
We recommend creating fixed size disks because, while they
eat up a little more disk space, they also perform better
making your VM feel a bit more responsive. Plus, you’ll know
how much disk space you’ve used and won’t get surprised w
hen your VM files start growing.

14. Setting Up a Virtual Machine
5.

15. Setting Up a Virtual Machine
6. You’ll then be able to set the size of the virtual disk. You’re
free to go with the default setting or change the size to suit
your needs. Once you click “Create,” the virtual hard disk is
created.

16. Setting Up a Virtual Machine
7. After that, you’re dumped back into the main VM app wind
ow, where your new VM should show up. Make sure the insta
llation media you need is available to the machine—usually
this involves pointing to an ISO file or real disc through the
VM’s settings. You can run your new VM by selecting it and
hitting “Start.”

17. Assignment
What is Sandbox ?
Virtual Machine Apps.
OS: Important Attributes, Key Features, Pros and Cons