Virtualization, VM Ware, Linux kernel and Linux

Virtualization, VM Ware, Linux kernel and Linux 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 Software. 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. 3rd Edition, OReilly Media.

College Students Cheating on Exams Essay

In today’s age when you look at the word â€Å"Cheating†, you may find many different definitions or meanings. Whether you cheat at work; known as fraud, cheat at home; known as dishonesty, or at school, this act of conduct can lead to many consequences made by ones choice. Cheating as a word to me means to not follow rules or standards brought up as a person. As we focus today on students cheating, the first thing that comes to my mind is cheating on an exam. As much as we hate to believe it, students in these days have followed the path of trying to do anything to get that grade. I believe many students today are driven to cheat when there is too much emphasis to ace an exam from both parents and school staff. It’s difficult to dismiss why students cheat, but I think if you eliminate pressure, students are less likely to engage in such conduct. Cheating leads to breaking the rules in many cases. Sometimes cheating can also lead to students finding someone else to help take one another’. No matter how careful teachers or programs are designed to prevent it, students will always find ways to get around obstacles and cheat at one point. Students may think cheating on an exam might seem like an easy way for a student to get a good grade and get ahead in his or her career, but the end result is when students cheat on exams, everyone is affected in many ways. When a student cheats or decides to cheat on an exam, they forget to think about the consequences that occur as a result of the decision made. Have you ever stopped and thought of the different consequences that occur? Consequences can vary depending on the student getting caught cheating. Some professors may issue a grade of a zero as a standard consequence; other professors may report the cheating to school board depending on the kind of test taken. In most cases, the student will be put on academic probation for repeat offenses which can affect the student’s career development. The student may be able to get a job with more responsibilities and more pay, but they may not be able to keep it, or might even harm people. Whether the student’s career is medical assistant, a teacher, or a lawyer, the exams are supposed to show the level of knowledge required for them to perform well and how can one show that when they are cheating on studies or exams. Another consequence of students cheating is that students, who cheat and get caught, cause other current and future students who do not cheat to become penalized for honesty. When students cheat they change the rules of education in favor of themselves. At the same time changing rules for themselves also cause changing rules for those that choose not to cheat, end result at one point or another someone will be affected. When you think of cheating, the question you should ask yourself should be; â€Å"Are you willing to take a huge risk and possibly affect your future? † The end result to cheating is obviously not a good turnout that leads to many different wrong roads. Many people say once a cheater, always a cheater meanings if you cheat once, are you bound to cheat again or will you learn from your mistakes. On the basis of predictability of human conduct, when you think of exams your first perception would be who is going to cheat on the exam. There are many different reasons why people cheat, just as there are differences in individuals who may cheat. For some, cheating is a way of life, one may cheat for some relief and in other cases others may cheat and be caught off guard causing a momentary slipup, which in end result may never happen again. Now what causes a person to act in that behavior, and determine what caused that behavior. What factors lead a person to cheat is what many ask. Eventually one can make a change and not cheat again. I believe schools should organize speakers, programs and workshops in the framework of â€Å"helping a student to cope with stress†. As part of these programs, parents should be made aware of how they often teach their children to cheat by increasing the pressure or demonstrating that success is the ultimate value in life. Students need to learn that you can cheat your way through school, graduate without learning anything, then get a profession and cause another person to get hurt due to not knowing anything in school due to cheating. Next time if you should cheat to make that extra grade, think again because it may result in hurting yourself and your future or the future of others.

Using Lo Que and Lo Cual to Form Noun Phrases in Spanish

Lo que and lo cual are common ways of forming a phrase that acts as a noun. Because lo que and lo cual are neuter, they are used to refer to an entire sentence, a thought, or an abstract concept rather than something specific. It is best to think of lo que and lo cual as single words with a space in the middle rather than trying to parse the individual particles. Lo que and lo cual can be translated as that or which, and it is also common for lo que to be translated as what or, more formally, that which. They function as relative pronouns, meaning they introduce a clause (a noun and an accompanying verb that dont form a complete sentence when standing alone) that provide more information about what lo que or lo cual refer to. An Annotated Example of Using Lo Que Heres an example of lo que being used three times in a paragraph. The paragraph is from ABC.es, a major news site in Spain. Antognini y otros colegas europeos y de EE UU presentan esta semana en science un estudio que seà ±ala que el protà ³n es mà ¡s pequeà ±o de lo que se cree. Los resultados confirman lo que el mismo equipo ya publicà ³ en Nature en 2010: El protà ³n parece ser 0,00000000000003 milà ­metros menor de lo que pensaban los investigadores. Here is one what in this except could be translated to English: Antognini and other European and American colleagues are presenting a study in science this week that indicates that the proton is smaller than what is believed. The results confirm what the same research team already published in Nature in 2010: The proton seems to be 0.00000000000003 millimeters smaller than what researchers thought. Examining these examples can show you how lo que is used; lo cual is used much the same way and is often interchangeable. In the first sentence, lo que introduces the clause se cree. Se cree is a conjugated reflexive form of creer, a verb meaning to believe or to think. The reflexive here is used like the passive voice in that it indicates something is believed without explicitly stating who is doing the believing, so it can be thought of as meaning is believed making lo que se cree meaning what is believed. What is believed is a concept that doesnt have gender. In the second sentence, lo que introduces el mismo equipo ya publicà ³ (the same team already published). So the complete phrase (lo que el mismo equipo ya publicà ³) means what the same team already published, again a concept without gender, which gives the reader more information about the research results. In the third sentence, the full phrase (lo que pensaban los investigadores) acts as a noun phrase functioning as a prepositional object of de. Again, what the researchers thought is a concept without gender. Sample Sentences Using Lo Cual El hotel està ¡ situado en lo alto de una colina, lo cual permite tener una panorà ¡mica de 360 grados de la regià ³n. (The hotel is situated on the top of a hill, which allows it to have a 360-degree panoramic view of the region. Lo cual gives us more information about a concept, that of the hotel being on a hill.) Oyeron unos 40 disparos, por lo cual salieron. (They heard some 40 gunshots, which is why they left.) Las tasas de natalidad y de mortalidad son muy altas, por lo cual el crecimiento natural de la poblacià ³n es muy lento. (The birth and death rates are very high, which is why the populations natural growth rate is very slow.) Las condiciones de temperatura deben ser controladas, lo cual es difà ­cil en una cocina. (The temperature conditions should be controlled, which is difficult to do in a kitchen.) Key Takeaways Lo cual and lo que can function as relative pronouns that refer to an entire sentence or a concept.Lo cual and lo que dont refer to specific things but rather to concepts or entire sentences.That, which, and what are common English translations for lo que and lo cual.

Essay on Morris Luries Pride and Joy - 1365 Words

Write about how one character from Morris Lurie’s Pride and Joy is presented and how this character develops key concerns in the story. Billy in Morris Lurie’s ‘Pride and Joy’ is initially presented as a 16 year old boy who literally lives his life in the footsteps of his abusive, irresponsible, bohemian father, Ned Mathews. By the end of the story Billy’s character has undergone a transformation to become his own person; he has broken away from his father. This short story is told in first person narrative by an anonymous narrator. This narrator is a tourist on an island in the â€Å"Great Barrier Reef† who tells his account of his encounter with millionaire Ned Mathews and his son, Billy. Through his characterization of Billy,†¦show more content†¦By exploring Billy’s inappropriate choice of lifestyle in great detail, Lurie expresses his theme, which is to take care when choosing your lifestyle. Billy’s desire to please his father and to control is reiterated by the motif of alcohol. Billy is too young to be drinking as much alcohol as he does, yet he does and he does it to please his father and to control by demonstrating that he is able to drink as much as his father. This is shown in the quotation, â€Å"His son [Billy] matched him drink for drink.† Lurie’s use of the narrator’s voice is very significant here because the narrator is presented to readers as very moral and sensible, so when the narrator talks about a boy drinking as much as a man we worry. This concern is further addressed by the narrative voice in the line, â€Å"I watched the boy. How long could he last? I thought. How long could he keep it up?† and also when he thinks, â€Å"Don’t tell me Billy is outdrinking him. I thought. His own son. His own pride and joy.† The pace is signi ficantly sped up during these two quotations by the shorter more choppy sentences. This serves two purposes, first it makes the passage stand out from the rest of the paragraph and second it permits the narrator to clearly state his point. The repetition of â€Å"I though† in both quotations creates an effective link of the two quotations. It is therefore reasonable to assume