Title: PLATFORM VIRTUALIZATION – Work with multiple operating systems simultaneously

Authors: P. Anusha & G. Anusha, 4th Year BTech, Information Technology Department

College: Prakasam Engineering College – Kandukur


Virtualization is a proven software technology that is rapidly transforming the IT landscape and fundamentally changing the way that people compute. Today’s powerful x86 computer hardware was designed to run a single operating system and a single application. This leaves most machines vastly underutilized. Virtualization lets you run multiple virtual machines on a single physical machine, sharing the resources of that single computer across multiple environments. Different virtual machines can run different operating systems and multiple applications on the same physical computer

We use a desktop which runs on a single operating system. We also see systems which have more than one operating system installed, but run on one via dual boot. The utilization percentage of these systems is much low when compared to the level of their capability.

By virtualization we can run simultaneously more than one operating system on the physical machine. The main idea behind this is to better utilize the available resources in an organization.


We are familiar with the concept of multiple processes running simultaneously and sharing the resources of a single computer. This is achieved by operating system acting as a single point of contact interfacing with the hardware resources, and there by controlling the access to hardware resources by multiple processes.

Virtualization can be thought of as an extension of this concept, where in multiple operating systems are allowed to share the hardware simultaneously by means of virtualization software.

An OS directly interacts with hardware in normal non-virtualized case. Now if we want to run multiple operating systems simultaneously, we need to have an abstraction layer between the OS and the actual hardware. This hardware abstraction layer fools the operating system into thinking that it is directly interacting with the hardware.

It is the one which enables the user to run more one than operating system simultaneously. On machines with single operating system the resources of that machine are set under that OS.

Here in case of virtualization there is a hardware abstraction layer called hypervisor or virtual machine monitor between the hardware and the operating system. With the help of this virtual machine monitor we can install and run more than on operating system. This hardware abstraction layer creates an illusion that each of the OS running is having its own resources, but actually they are sharing the same resources.


Here the virtualization provides an abstraction, which is very similar, but not completely identical to the underlying hardware. Xen Virtual Machine and VMware ESX server are examples of this technique. Instead of completely emulating the underlying hardware architecture by the virtualization software, the virtualized guests collaborate with the hypervisor to achieve optimal performance. Para virtualization offers significantly improved performance; however, it requires modification to guest operating system. The guest OS is modified at low time to include Para Virtualization extensions. Hence it requires cooperation from the OS vendor.

Ex: sun xVM virtual box


Here the virtualization software provides a complete emulation of the underlying hardware. All software that can run on the underlying hardware can run as is, on the virtual machine. The operating system does not need any modifications to be run as a guest OS instance. The guest OS instance can be any operating system supported by the underlying hardware.

Ex: VMware workstations, Virtual PC, QEMU.

With virtualization we can be

a) ble to dynamically move resources

b) Able to share resources

c) Making better use of the resources

d) Driving up utilization

After installing and running sun xVM virtual box it looks like this


A virtual machine is a tightly isolated software container that can run its own operating systems and applications as if it were a physical computer. A virtual machine behaves exactly like a physical computer and contains it own virtual (i.e., software-based)CPU, RAM, harddisk and network Interface card(NIC).

An operating system can’t tell the difference between a virtual machine and a physical machine, nor can applications or other computers on a network. Even the virtual machine thinks it is a “real” computer. Nevertheless, a virtual machine is composed entirely of software and contains no hardware components whatsoever. As a result, virtual machines offer a number of distinct advantages over physical hardware.

The VMware virtualization platform is built on a business-ready architecture. Use software such as VMware Infrastructure and VMware ESXi to transform or “virtualize” the hardware resources of an x86-based computer—including the CPU, RAM, hard disk and network controller—to create a fully functional virtual machinehat can run its own operating system and applications just like a “real” computer. VMware virtualization works by inserting a thin layer of software directly on the computer hardware or on a host operating system. 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. You can safely run several operating ssystems and applications at the same time on a single computer, with each having access to the resources it needs when it needs them.


A virtual infrastructure lets you share your physical resources of multiple machines across your entire infrastructure. A virtual machine lets you share the resources of a single physical computer across multiple virtual machines for maximum efficiency. Resources are shared across multiple virtual machines and applications. Your business needs are the driving force behind dynamically mapping the physical resources of your infrastructure to applications—even as those needs evolve and change. Aggregate your x86 servers along with network and storage into a unified pool of IT resources that can be utilized by the applications when and where they’re needed. This resource optimization drives greater flexibility in the organization and results in lower capital and operational costs.

A virtual infrastructure consists of the following components:

• Bare-metal hypervisors to enable full virtualization of each x86 computer.

• Virtual infrastructure services such as resource management and consolidated backup to optimize available resources among virtual machines

• Automation solutions that provide special capabilities to optimize a particular IT process such as provisioning or disaster recovery.

Decouple your software environment from its underlying hardware infrastructure so you can aggregate multiple servers, storage infrastructure and networks into shared pools of resources. Then dynamically deliver those resources, securely and reliably, to applications as needed.

Virtual Machines Benefits

In general, VMware virtual machines possess four key characteristics that benefit the user:

Compatibility: Just like a physical computer, a virtual machine hosts its own guest operating system and applications, and has all the components found in a physical computer (motherboard, VGA card, network card controller, etc). As a result, virtual machines are completely compatible with all standards x86 operating systems, applications and device drivers, so you can use a virtual machine to run all the same software that you would run on a physical x86 computer.

Isolation: While virtual machines can share the physical resources of a single computer, they remain completely isolated from each other as if they were separate physical machines. If, for example, there are four virtual machines on a single physical server and one of the virtual machines crashes, the other three virtual machines remain available. Isolation is an important reason why the availability and security of applications running in a virtual environment is far superior to applications running in a traditional, non-virtualized system.

Encapsulation: A virtual machine is essentially a software container that bundles or encapsulates a complete set of virtual hardware resources, as well as an operating system and all its applications, inside a software package. Encapsulation makes virtual machines incredibly portable and easy to manage. For example, you can move and copy a virtual machine from one location to another just like any other software file, or save a virtual machine on any standard data storage medium, from a pocket-sized USB flash memory card to an enterprise storage area networks

Hardware Independence: Virtual machines are completely independent from their underlying physical hardware. For example, you can configure a virtual machine with virtual components (e.g., CPU, network card, SCSI controller) that are completely different from the physical components that are present on the underlying hardware. Virtual machines on the same physical server can even run different kinds of operating systems (Windows, Linux, etc).

SUN xVM Virtual Box: SUN Microsystems developed a virtual box. This Virtual Box allows the guest code to run unmodifned, directly on the host computer, and the guest operating system “thinks” it’s running on real machine.

The techniques and features that Virtual Box provides are useful for several scenarios:

Operating system support: With Virtual Box, one can run software written for one operating system on another (for example, Windows software on Linux) without having to reboot to use it. You can even install in a virtual machine an old operating system such as DOS or OS/2 if your real computer’s hardware is no longer supported.

Infrastructure consolidation: Virtualization can significantly reduce hardware and electricity costs. The full performance provided by today’s powerful hardware is only rarely really needed, and typical servers have an average load of only a fraction of their theoretical power.

Testing and disaster recovery: Once installed, a virtual box and its virtual hard disk can be considered a “container” that can be arbitrarily frozen, woken up, copied, backed up, and transported between hosts. On top of that, with the use of another Virtual Box feature called snapshots, one can save a particular state of a virtual machine and revert back to that state, if necessary.

Host key: Right control is the default host key. When we press the right ctrl we move from one OS to another OS.


Virtualization dramatically improves the efficiency and availability of resources and applications in your organization. Internal resources are underutilized under the old “one server, one application” model and IT admins spend too much time managing servers rather than innovating Here are the key benefits of server virtualization for small and medium businesses.
1. Reduce Cost:

By consolidating multiple applications onto one or a few servers, virtualization lowers the number of servers required to handle a given workload. Fewer servers mean reduced space, power consumption, cooling and maintenance costs, licensing fees and environmental impact. In brief, virtualization allows businesses to get more from their current configuration so they can improve their return on assets. Since server administration is greatly simplified, virtualization can also reduce IT staff costs.
2. Improve asset utilization:

In the traditional one-application-per-server model, the average company uses only 10% of its available server power. As a result, substantial computing power sits dormant at any given moment. With virtualization, applications are consolidated onto fewer servers so usage becomes significantly more efficient — as much as 90% for peak loads.

Virtualization also can improve server resilience and business continuity. Because applications are partitioned on a virtual machine, they can fail “in isolation” without bringing down other servers or your network. In the event of an equipment failure, data and virtual machines automatically switch to unharmed devices, which allow you to recover quickly from business interruptions. Likewise, you can test new applications in a virtual environment and deploy them automatically, meaning that backup and migration maintenance outages can become a thing of the past.
3. Enhance management:

Virtualization improves server management in two major ways. First, since applications are consolidated, there is less hardware to manage. Perhaps more importantly, virtualization software comes with management tools that simplify server administration, such as intuitive “click and drag” interfaces. Since your staff can manage two or three times as many servers as before, you may be able to reduce personnel and training expenses.
4. Increase flexibility:

Adding resources to support high-demand applications in a traditional environment requires new servers and storage arrays to be wired into the system. In a virtualized environment, additional resources are provided to that application on the fly, and data placement is optimized to maximize performance and utilization of disk space without having to re-provision or install a new server. As a result, your critical applications always get the resources they need and save you the cost of “peak time” hardware.
5. Allow faster resource deployment:

When your business needs to adapt to IT changes – supporting strategic business initiatives, managing workload changes, adding new equipment, responding to disasters and such — virtualization significantly increases deployment speed. In fact, you can set up new virtual machines, servers and storage in minutes.

With all these benefits, it’s no wonder that virtualization is growing so quickly; IDC forecasts that 50% of servers will be virtualized in 2011, up from 7% in 2007. If your business hasn’t virtualized its environment yet, don’t worry — it’s easier than you think, even for small and medium businesses. Now is the perfect time to gain the benefits of this important technology.
6. Get more out of your existing resources:

Pool common infrastructure resources and break the legacy “one application to one server” model with server consolidation
7. Reduce datacenter costs by reducing your physical infrastructure and improving your server to admin ratio:

Fewer servers and related IT hardware means reduced real estate and reduced power and cooling requirements. Better management tools let you improve your server to admin ratio so personnel requirements are reduced as well.
8. Increase availability of hardware and application for improved business logic:

Securely backup and migrate entire virtual environments with no interruption in service. Eliminate planned downtime and recover immediately from unplanned issues.
9. Gain operational flexibility:

Respond to market changes with dynamic resource management, faster server provisioning and improved desktop and application deployment.
10. Improve desktop manageability and security:

Deploy, manage and monitor secure desktop environments that users can access locally or remotely, with or without a network connection, on almost any standard desktop, laptop or tablet PC.


Virtualization enables us to run more than one operating system at once.

Hence it is very easy for a programmer to evaluate his program simultaneously in different operating system.

It becomes easy for various organizations to provide a new desktop for a newcomer with existing resources.

Effective utilization of resources.

Therefore download and install a virtual box

Next install different operating systems of your needs and have fun.







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