毕业设计英文外文翻译虚拟服务器Word文件下载.docx

1、As are physical servers, a virtual PC is useless until you install an operating system on it. The operating systems that you install on your virtual hosts are called guests. Installing a guest OS can be as easy as booting from the OSs installation CD. Its just like installing an OS on a PC, and in g

2、eneral, if you wonder how virtualization will behave, thats the answer: Just like a PC. In fact, in an all-Windows environment, its easy to lose your place: Are you looking at your Windows host OS or at one of the four Windows guest OSes you just installed? You might get confused, but your guest OSe

3、s and their applications never do. Each guest OS believes it has the whole machine to itself. And, in a sense, it does. Software-based hardware Operating systems and applications running on virtual servers dont have direct control over resources such as memory, hard drives, and network ports. Instea

4、d, the VM that sits beneath the OS and applications intercepts requests for interaction with hardware and handles them as it sees fit. The real mindblower that turns this technology into something close to magic is that a world-class virtualization solution such as VMware ESX Server can synthesize a

5、n entire hardware configuration that has little resemblance to the underlying hardware. For example, the host might simulate the initialization process of a SCSI controller to the last detail, convincing the guest OS that this initialization is being performed even when no physical SCSI controller e

6、xists. It can make IDE drives look like SCSI drives, convert network shares into locally attached storage, turn one Ethernet adapter into several, and create gateways between older operating systems and unsupported modern hardware such as Fibre Channel adapters. You build your own servers that preci

7、sely fit the needs of your applications, but you use a mouse instead of a screwdriver. Installing the OS and software onto a physical PC server every time you need one can be tedious. Fortunately, with virtualization you dont have to. After youve tuned a virtualized hardware configuration precisely

8、to your liking, you can save that servers disk image to a file and use it as a template for other guest systems. In practice, this is a delight. You can back up a virtual server by copying the file. You can create a new server by duplicating the filecopying Windows requires reactivation and an appro

9、priate licenseor move an existing server to different physical hardware. Virtualized servers do all the good and bad things regular servers do. They boot up, power down, suspend, hang, and even crash. If a guest OS or a device driver it uses is buggy, the virtual PC will crater. But not the physical

10、 computer, and thats key. If your OS crashes or an application hangs, or even if you install a software fix that requires a reboot, nothing happens to the hardware. One virtual machine can fail over to another in a purely virtual sense or in a way thats closer to the real thing. Even if certain hard

11、ware devices have malfunctioned, so long as the fail-over target is configured to use a secondary network adapter and an alternate path to storage, the fail-over will work exactly as it would if the virtual PCs were physical PCs. In most cases, an enterprise management system will monitor and react

12、to a virtual fail-over as if it were the real thing. Solutions such as HP OpenView see and interact with virtual servers the same way they do with physical ones. The reported configurations of the servers will change after theyre virtualized, but its entirely likely that the day-to-day management of

13、 your shop will experience little change. Why build the suppositional lead plane？Internet becomes the focal point that the business family fixes eyes on gradually, in development of technology swift and violent today, enterprises informationize already becoming important market competition Duan. One

14、 of trend marketplace , trend internationalization or the necessary condition keeping home market wont shrink is to must own the unimpeded modern times international connection means: Self domain name , self host page , self electron mailbox , self propagating position. Where , condition now to be m

15、ember of disregarding your enterprise how, that hard disk space rents out , the suppositional lead plane of network serves a server uses all these becomes reality!The network becomes a important way of marketing and sales already gradually , that any enterprise carries out upper Electronic Commerce

16、of net all is a piece of very prudent thing but, because of its throwing into on manpower and material resources is very big. When not satisfying sufficient requirments enterprise, building a trial supposing a lead plane to carry out ElectronicCommerce first on the network is very necessary. Let the

17、 special field company come to bear the systematic upkeep and manage, feasible enterprise can save more manpower and cost compose other business. You have owned the suppositional lead plane （website server） having founded self right away having caught with a net electron advertisement over a long pe

18、riod of time.）In addition, most virtualization systems bundle solution-specific management software, allowing an administrator to sit at a central console and manipulate all the virtual servers in an enterprise. Its quite an eye-opener to swap out a virtual Ethernet card without ever touching the ha

19、rdware. A virtualization solutions management console gives you a degree of control over your virtual PCs that surpasses what administrators can do with traditional tools. From a central location, you can boot and shut down virtual PCs as needed. Its also possible to pause them, which harmlessly fre

20、ezes them in their current state, or hibernate them, putting them in a deep freeze by saving their state to a file on disk. By overwriting the disk file, you can restore PCs from a backed-up state and roll back changes that rendered the guest inoperable, all from a terminal session. In environments

21、with a mix of operating systemsa common condition that turns even simple consolidation into a messy affair one solution would be to host each OS in its own VM. For example, on a PC server running one of VMwares virtualization solutions, you can run any combination of Windows 2003 Server, Windows 200

22、0, Windows NT 4.0, various flavors of Linux, and FreeBSD. You can even use VMs to host different versions of the same OS. Linux software is infamous for dependence on specific versions and vendor distributions of Linux. Virtualization is the only way to run applications designed for Red Hat 7.2 and

23、Suse 9.0 simultaneously on a single server. Virtualization is magnificent stuff, but it doesnt cure all ills. You can never create a virtual PC that outperforms the physical system underneath. You will learn much about your applications system requirements from moving them to a virtual environment.

24、Theyll likely surprise you, either with how little of the original server they usedthats the typical caseor how piggish they are. If necessary, you can throttle the nasty ones down. And while one of the great benefits of virtualization is securityits hard to accomplish much by cracking a system that

25、 doesnt exista virtualized PC can still be compromised. Fortunately, the cure is to overwrite the virtual PCs disk image with one thats known to be clean, but managing virtual servers still requires vigilance. Ultimately, hardware consolidation is only one reason to opt for server virtualization, an

26、d it has wide appeal. Still, depending on each departments unique needs, IT managers are sure to find innumerable ways that virtualization can benefit your enterprise. （The End）虚拟服务器服务器的虚拟化是少有的几种技术之一，它们听上去好的好像很不真实，但实际上是真的。虚拟服务器在早期的用途是减少使用率不足的服务器硬件，将处理任务集中到数量更少的机器上。自这些早期应用以来，现在已经发展成一种多目的的解决方案，实现更高的可靠

27、性、更好的管理、以及成为企业数据中心管理员不可或缺的工具。 按照非常简化的定义，虚拟服务器仅仅是利用单独的软件来模拟计算机的独立行为和能力。虚拟化实质上是一个很简单的术语，服务器虚拟化。软件底部的堆栈是直接安装在服务器硬件上的普通的操作系统。其上是处理重新定向和仿真的虚拟层，而重新定向和仿真构成了虚拟计算机。这底部的两层合起来被叫做宿主机。宿主机提供大家熟悉的PC机BIOS ROM的全部工作，按照用户的选择，利用改变用户定义的配制而生出很多独立的PC机。作为物理的服务器，一个虚拟的PC机在没有安装操作系统之前是不可以使用的。安装在虚拟宿主机上的操作系统称作OS。安装客操作系统OS非常简便，只需

28、从OS的安装光盘上引导过来。这和PC机上安装OS没有什么两样。一般来说，如果你对虚拟化是如何运转的感到惊奇，那么这就是答案：就像一台PC机。事实上，在一个全Windows环境下，你很容易迷失了方向：是在看Windows宿主机OS，还是在看刚刚安装的四个Windows客OS中的一个？你自己可能产生困惑，但你的寄宿OS及其应用程序是从来不会弄错的。每个寄宿OS认为它拥有整个机器。在某种意义上，它是拥有整个机器。基于软件的硬件 连续运行在虚拟服务器上的操作系统和应用程序不直接控制内存、硬盘和网络端口等资源，取而代之的是位于OS和应用程序之间的VM（虚拟机）截取与硬件交互的请求并在认为合适时对它们进行

29、处理。真正将此技术变成接近于魔术的是VMware公司的ESX Server等世界级的虚拟化解决方案，这类解决方案能合成整个硬件的配置，而它与基础的硬件几乎没有关系。例如，宿主机可以最详细地模拟SCSI控制器的初始化过程，让客OS相信即使不存在物理的SCSI控制器时初始化也在被执行。它能使IDE磁盘机看上像SCSI磁盘机，能将网络共享的磁盘机转换成装在本机内的存储设备，将一个以太网卡变成几个网卡，并能在较老式的操作系统和它不支持的新式硬件（如光通道卡）之间生成网关。你可以建立完全适合应用程序需要的属于你自己的服务器，这时你用的是鼠标而不是用改锥。在每次需要时把OS和软件装到物理的PC服务器是很烦人的。幸亏有了虚拟化你就不必这么做。在完全按你的