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The Von Neumann Computer is a digital pc that storing the data i

Virtualization, VM Ware, Linux kernel and Linux device drivers

Virtualization is a system or rather a technique for hiding the physical characteristics of computing resources from the way in which other systems, applications, or end users interact with those resources. This consists of making a single physical resource (like a storage device, a server, an application, or an operating system) appear to operate as multiple logical resources. It can also comprise making multiple physical resources (like storage devices or servers) appear as a single logical resource. It can also take in making one physical resource to appear, with fairly diverse characteristics, as one logical resource.

It is the universal theme of all virtualization technologies to hide the technical detail by means of encapsulation. An external interface that hides an underlying implementation (for example, by simplifying a control system, by combining resources at different physical locations, or by multiplexing access) is created by virtualization. Owing to the recent development of new virtualization platforms and technologies, attention has been refocused on virtualization. It is a confirmed software technology. Through this technology, the IT landscape is speedily transforming and the manner of computing is also fundamentally changing. (VMWare 2008)

The technology of virtualization can benefit any person who uses a computer, from the IT professionals and Mac enthusiasts to commercial businesses and government organizations. It saves time, effort and money while it also achieves more with the computer hardware already owned by the users. (VMWare 2008)Virtualization is used in various diverse contexts; they can be grouped into two major types: Platform virtualization involves the simulation of whole computers; and resource virtualization involves the simulation of combined, fragmented, or simplified resources. Certainly, it is also an important concept in non-computer contexts. A virtualized interface is employed to a complex device by many control systems; therefore gas pedal of a modern car does much more than simply increasing the flow of fuel to the engine.

The returns on investment in any business can be improved with the use of Virtualization. It effectively lets one computer to do the job of multiple computers, through sharing the resources of a single computer across multiple or several environments. Virtual servers and virtual desktops allow hosting multiple operating systems and multiple applications locally as well as in distant and inaccessible locations. It gives freedom from physical and geographical limitations. Better desktop management, improved disaster recovery processes, increased security, and high availability of resources are the other benefits that one gets from building a virtual infrastructure apart from the basic advantages that are savings in energy and lower capital expenses because of more efficient use of the hardware resources. There are some benefits of virtualization, which are as follows:

• Through virtual machines, the workloads of several under-utilized servers can be consolidated to a smaller number of machines, possibly a single machine. This results in benefits of savings on hardware, environmental costs, management, and administration of the server infrastructure.
• They also serve the purpose of running the legacy applications. A legacy application just might not operate on newer hardware or operating systems. And if it runs on it, there may be under-utilization of the server; therefore consolidation of several applications is useful. This is not easy to do without virtualization; applications are usually not written to co-exist within a single execution environment.
• Virtual machines offer safe and isolated sandboxes for running applications that can not be trusted upon. Such an execution environment can also be created dynamically – on the fly – as something is downloaded from the Internet. Virtualization plays an important role in building secure computing platforms.
• They can be used to create operating systems or execution environments with resource limits. Generally, partitioning goes together with quality of service in design of QoS-enabled operating systems.
• The illusion of hardware or hardware configuration (including the multiple processors and SCSI devices) is provided by the virtual machines. It simulates networks of independent computers.
• They can run multiple operating systems at the same time, which are of entirely different nature. Some such systems may be hard or impossible to run on newer real hardware.
• They allow powerful debugging and performance monitoring. Debugging of operating systems can be done without losing productivity, or creating more complicated debugging scenarios.
• Whatever is run by the virtual machines, can also be isolated by them. So, they provide fault and error containment. Faults can be injected proactively into software in order to study its consequent behavior.
• Application and system mobility is helped by the virtual machines, since they make migration of software easier.
• They are excellent tools for research and academic experiments. It is safer to work with them because they provide isolation. They sum up the complete state of a running system: the state can be saved, examined, modified, and reloaded.
• The existing operating systems can run on shared memory multiprocessors.
• They can create arbitrary test scenarios and can result in some very imaginative, effective quality assurance. Virtualization can retrofit new features in the existing operating systems without “too much” work.
• Several tasks including the system migration, backup, and recovery can be made easier and more manageable.
• It is an effective means of providing binary compatibility. In co-located hosting, virtualization on commodity hardware is extremely popular. Such hosting is economical, secure, and appealing on the whole.

In core, it can be said that virtualization helps to convert hardware into software. The software like VMware and ESX helps to transform the resources of an x86-based computer hardware that includes the CPU, RAM, network controller and hard disk. In order to create a virtual machine, this is fully functional and capable of running its own applications and operating system similar to a real computer. Multiple virtual machines are known for sharing the resources of hardware without having any interference among each other. This helps to safely run the various operating systems and applications on a single computer.

VMWare

The VMware Approach to Virtualization: This approach inserts a fine layer of software directly on the hardware of computer or might be on a host operating system. This layer of software is capable of creating machines that are virtual and contain a monitor of virtual machine. This allocates hardware resources energetically and transparently. This helps the multiple operating systems to run on a single physical computer concurrently. (VMWare 2008) Virtualizing a single physical computer marks the beginning. A robust virtualization platform is provided by the VMware. This helps to scale the hundreds of interlinked physical computers and storage devices that can form complete virtual infrastructure.

VMware, Inc. is a publicly-listed company on the New York Stock Exchange. It designs and develops proprietary virtualization software products for x86-compatible computers, counting commercially-available as well as freeware versions. The desktop software of VMWare runs atop Microsoft Windows, Linux, and Mac OS X. The enterprise level software and the ESX Server of VMWare run directly on the server hardware without the need of an extra core operating system. The name VMware comes from the abbreviation “VM”, which means “virtual machine” and ware comes from second part of Soft’ware’.

Achieving the Benefits of Virtualization: VMware’s proven technology is the basis of free VMware Server. With the help of this software, which is robust yet easy to use, many things can be done. Developers can create multiple environments by means of different operating systems on the same server so as to restructure software development and testing. New applications, IT testing of patches and operating systems can be simplified by permitting system administrator to test in secure virtual machines and by leveraging snapshots to be able to roll back to a clean state.

Server positioning can be simplified by once building a virtual machine and then developing it multiple times. In ready-to-run virtual machines, software can be evaluated without installation and configuration. Legacy operating systems such as Windows NT Server 4.0 and Window 2000 Server can be re-hosted in a virtual machine running on new hardware and operating system.

Pre-built, ready-to-run virtual appliances can be leveraged, which include virtual hardware, operating system and application environment. On Virtual Appliance Marketplace, virtual appliances for web, file, print, proxy, email and other infrastructure services are available for download. Free operating systems have several advantages as characterized by Linux. One of which is that their internals are open for all to view. Anybody, who has requisite skills, can readily examine, understand and modify the operating system, which is once considered as a dark and mysterious area whose code was restricted to a small number of programmers.

Operating systems can be democratized with the help of Linux. The Linux kernel is a large and complex body of code, which is not possible to be hacked. Kernel hackers would need an entry point where they can approach the code without being disturbed by the complexity of its codes. Frequently, the gateway is provided by device drivers (Corbet, Rubini & Kroah-Hartman 2005).

In Linux kernel, device drivers play an important role. These device drivers are a different kind of black boxes that make a particular hardware piece respond to a well-defined internal programming interface. Also, they completely hide the details regarding the working of the device. With the help of a set of standardized calls that are independent of the specific driver, various user activities are performed. The role of device driver is to map those calls to device-specific operations that act on real hardware.

The writing of Linux device drivers is interesting because of number of reasons. In order to gain access to a particular device that is of their interest, individuals need to know about the drivers. By making a Linux driver available for the products, hardware vendors can add large and growing Linux user base to their potential market (Corbet, Rubini & Kroah-Hartman 2005). It is necessary to reliably run the Linux kernel without considering whether a new hardware is added or removed from the system. Due to this, an additional burden is placed on the device driver author.

For USB drivers, when the device with which a USB driver is bound with, is removed from the system, the pending urbs that were submitted to the device begin to fail with the error – ENODEV. The driver is required to identify the error and properly clean up any pending I/O if it occurs. The hot pluggable devices are not only limited to the traditional devices like the mice and keyboards. Now, number of systems supports the removal and addition of the complete CPU’s and memory sticks. The Linux kernel properly handles the addition and removal of such core system devices so that there is no need for the individual device drivers to pay attention to these things.

References

VMWare 2008, Retrieved April 17, 2008 from www.vmware.com

Mullins, R 2007, VMware the bright spot on a gray Wall Street day, IDG News Service.

Corbet, J, Rubini, A & Kroah-Hartman, G 2005, Linux Device Drivers. 3^rd Edition, O’Reilly Media.

n a single separate way and it use a processing unit. A digital computer keeps its program in instruction with its data as well. The Von Neumann Computer named after name of computer scientist John von Neumann.

5 Internal Components: Description of each components, how they are connected to Mother Board, Diagram.

Hard Disk: Hard disk is a magnetic disk that allows you to store your computer data, a hard disk consist of several platters, which every individual platter is able to read and write. The hard disk is connected to the motherboard by ribbon cable (ATA66/100).

Random Access Memory (RAM:

It is type of computer memory but it can be accessed randomly, RAM is very fast to read than any storage device in a PC. As long as your computer is running the data store in a RAM but when the computer turns off, Ram will lose its data. The Ram connected to the motherboard by small circuit, in the motherboard there is two circuit places which is one for inline memory and the second is duel inline memory.

Processor: Processor or Central Processing Unit (CPU) it is part of computer system and in easy way it is a brain of computer the job of CPU in a computer is to give a instruction for any computer program the processor is connected to the motherboard directly.

Graphic Card: It is a bridge between processor and other devices to send command and gets back the signal, the Graphic Card is connected throw the expansion slot which is in the Motherboard.

5 External Components: Description, how are they connected? Eg Ports, USB, etc. Diagram.

Key Board: keyboard is primary way to communicate with input; you can use the keyboard to input text and data. When we press a key, it presses a button, completing the circuit and allowing an amount of current to run through and keyboards are connected by USB cable or PS2.

Mouse: mouse is device which lets you work with graphical objects that the computer displays on the screen. Mouse has one button or sometimes three buttons and it have scroll wheel that enable user to scrolling long document or webpage. The Mouse is connected by USB cable or PS2.

Printer: It is a device that can print text or graphic that stored in a electronic form, and it connect to the PC by USB Port.

Scanner: It is a device that scans data or any text, printed page or photo you scan it to the computer and it connected to the computer by USB Port.

Monitor: A Monitor is like a television but the difference is that monitor display the information produced by a computer, basically it is a screen display of a computer and it connect VGA port in a PC or in some PC by the Video card.

Task 2 Describe the characteristics of the various types of internal memory of computer:

What is internal memory of computer?

The internal memory of computer is also part of computer devices that recoding media that keep digital data used for computing for some interval of time.

What are the major types of internal memory of computer? For each type of internal memory, explain how it works and what are its major characteristics

There are types of computer internal memory which is Random Access Memory (RAM) and Read Only Memory (ROM).

Random Access Memory (RAM): It is a temporary computer internal memory and it is a space that allows us to temporarily store data when a program is running. The contents are being lost when the computer is switched off it only holds data while power is on.

There are some major types of RAM which are

:

Rambus DRAM (RDRAM): is a serial memory technology that arrived in three flavours, PC600, PC700, and PC800. PC800 DRAM has doubled the maximum throughput of old, but a higher speed and it use small capacitors to store each bit of memory in an addressable format that consists of rows and columns, DRAM designs with multiple channels.

SIMM chips: Single in-line memory modules (SIMMs) it is a type of solid state computer memory which is used particular for the processor cache memory. The 72-pin SIMM has a notch among the contacts in the middle. An important characteristic of RAM is that the entire memory place can be accessed at almost the same speed.

Read Only Memory (ROM): Is a kind of memory that store the data permanently and it cannot be removed, eventually every computer is coming with a small amount of ROM which recorded of boot firmware, when we start our computer the ROM chips will running hardware diagnostics that will loading the operating system into RAM.

Cache: The cache will make our computer more skilled and better, your computer memory, cache is extremely fast memory that store data and the data is accessible quickly and it gives quickest response to the CPU.

Virtual Memory: The virtual memory task was to enable a process to operate or establish the status of pages in its virtual address space.

Task 3 Explain the purpose and functions of the system busses of a computer:

Explain how the internal subsystems are linked through buses and where these buses could be found inside a computer.

The computer internal subsystems are connect to the busses through wire inside the computer and the data transfer throw these from one part to the another part of computer. Busses connect the entire computer component with the main memory and processor.

Explain the functions of control, data, and address busses. What is “bus width” and what is the effect of the “bus width” on the bus performance?

The architecture of buses is a wire inside a computer which data is transfer from one part to another part inside the computer, the purpose of buses is to connect the entire computer component to the processor and to the central memory. Busses are dividing into two parts the Data busses and Address busses. The function of data busses is to transfer the data and the function of address busses is to give direction to data where to go. Bus width is a canal that information is flowing; when the bus width is wider it is beneficial for busses because more information can flow in more speedy time.

What is a motherboard “chip set”? With use of a diagram, explain what is the role and characteristics of the North and South Bridge of a motherboard.

It is a specific chip in a computer that calls motherboard chipset. The Northbridge is core logical in a computer motherboard and its role is to hold communication with RAM, BIOS ROM, PCI and CPU. The South Bridge job is to manage the basic of input/output These include all hard drive and expansion slots, USB, FireWire, RAID, audio codes, real-time system clock, system power management, interrupt controller, direct memory access (DMA) controller, and non-volatile BIOS memory.

Task 4 Describe, with the aid of diagrams, what are the components and

the structure of CPU and how CPU works:

What is the CPU of a modern computer and what are the CPU components?

The Central Processing Unit (CPU) is the brain of a computer that gives function to a computer programme. Every time when CPU doing a job there is a stored code in the computer’s memory that instructs the CPU what to do. CPU needs to decode the instruction code to find what it needs to do finish the task. After the CPU solve the code, the CPU will start to perform calculation and the result whether it store the result back in memory, to hard drive, or the computer display. The way that we can understand how powerful a process is by the number of instruction that a CPU can execute per second.

The CPU components are:

Logic or Arithmetic unit (ALU) it performs calculations, there are four types of function that ALU do and it depends on these to perform and they are addition, subtraction, multiplication and division even registering and instruction.

Register or the memory which stores the data, it tell CPU where the information is located, also it’s a temporary storage areas for instructions or data and they are not part of the memory. Register hold and transfer instructions. Register operate faster than a Ram, normally register assess by bit like 32 bits.

Control unit which give direction to the data around the CPU by sending control signals and it’s job is to control the data that executed by the ALU, also the Control Unit keeping communicate with ALU and system memory.

Use a diagram to explain the components of CPU

CPU Components Diagram

Arithmetic Logic Unit (ALU)

Registers

Control Unit

Input Device

Secondary Storage

Output Device

Explain shortly the Fetch Execute Cycle of CPU referring to its components and RAM.

Fetch Execute Cycle of CPU it is an order of actions that the central processing unit (CPU) perform to execute each machine code instruction in a program. There are five register in the Fetch Execute Cycle which are:

The Instruction Register that hold the solved and executed last instruction. The memory buffer register that use to get data from memory. The memory address registers that to be use when a word is transferred between memory and MBR. The accumulator job is to hold the result of ALU for the time being and the programme counter that hold the address of the next instruction to be fetched from memory.