In computing Computing is usually defined as the activity of using and developing computer technology, computer hardware and software. It is the computer-specific part of information technology. Computer science is the study and the science of the theoretical foundations of information and computation and their implementation and application in computer, a disk is an exact copy of a data The term data means groups of information that represent the qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which information and set. On the Internet The Internet is a global system of interconnected computer networks that use the standardized Internet Protocol Suite to serve billions of users worldwide. It is a network of networks that consists of millions of private and public, academic, business, and government networks of local to global scope that are linked by copper wires, fiber-optic, a mirror site is an exact copy of another Internet site. Mirror sites are most commonly used to provide multiple sources of the same information, and are of particular value as a way of providing reliable access to large downloads In networks, to download means to receive data to a local system from a remote system, or to initiate such a data transfer. Examples of a remote system might from which a download might be performed include a webserver, FTP server, email server, or other similar systems. A download can mean either any file that is offered for downloading or that. Mirroring is a type of file synchronization File synchronization in computing is the process of making sure that files in two or more locations are updated through certain rules.[citation needed].
A live mirror is automatically updated as soon as the original is changed.
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Reasons
Mirroring of sites occurs for a variety of reasons.
- To preserve a website or page, especially when it is closed or is about to be closed.
- To allow faster downloads for users at a specific geographical location. For example, a U.S. The United States of America is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the server could be mirrored in Japan Japan is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. The characters which make up Japan's name mean "sun-origin", which, allowing Japanese Internet users to download content faster from the local Japanese server than from the original American one. This may be viewed as caching on a worldwide scale.
- To counteract censorship Censorship is the suppression of speech or deletion of communicative material which may be considered objectionable, harmful, sensitive, or inconvenient to the government or media organizations as determined by a censor and promote freedom of information Freedom of information refers to the protection of the right to freedom of expression with regards to the Internet and information technology (see also, digital rights). Freedom of information may also concern censorship in an information technology context, i.e. the ability to access Web content, without censorship or restrictions. For example, an activist Activism, in a general sense, can be described as intentional action to bring about social change, political change, economic justice, or environmental wellbeing. This action is in support of, or opposition to, one side of an often controversial argument might post pictures on a website of a company conducting illegal activities or make available information on secret government activity and be litigated A lawsuit is a civil action brought before a court of law in which a plaintiff, a party who claims to have received damages from a defendant's actions, seeks a legal or equitable remedy. The defendant is required to respond to the plaintiff's complaint. If the plaintiff is successful, judgment will be given in the plaintiff's favor, and a range of for such. Other internet users will make the content in question available on other servers when the legal action results in the cancellation of ISP An Internet service provider is a company that offers its customers access to the Internet. The ISP connects to its customers using a data transmission technology appropriate for delivering Internet Protocol datagrams, such as dial-up, DSL, cable modem, wireless or dedicated high-speed interconnects or DNS The Domain Name System is a hierarchical naming system for computers, services, or any resource connected to the Internet or a private network. It associates various information with domain names assigned to each of the participants. Most importantly, it translates domain names meaningful to humans into the numerical (binary) identifiers services for the original activist.
- To provide access to otherwise unavailable information. For example, when the popular Google Google Inc. is an American public corporation, earning revenue from advertising related to its Internet search, e-mail, online mapping, office productivity, social networking, and video sharing services as well as selling advertising-free versions of the same technologies. Google has also developed an open source web browser and a mobile operating search engine was banned in 2002 by the People's Republic of China b. ^ Information for mainland China only. Hong Kong and Macau are excluded. In addition, the territories under the jurisdiction of the Republic of China, commonly known as Taiwan, are also excluded, the mirror elgooG elgooG is a literal mirror image of the Google search engine. Like Pimp my search, elgooG is a satire of Google. The site was created by a group called All Too Flat, who put up various comedy and satire pages on their website. To search on this search engine, a user must type in the keywords backwards for it to understand the search string was used as a way of effectively circumventing the ban.
- To preserve historic content. Financial constraints and/or bandwidth prevent the maintainers of a server from keeping older and unsupported content available to users who still may desire them - a mirror may be made to prevent this content from disappearing.
- To balance load. If one server is extremely popular a mirror may help relieve this load: for example if a Linux Linux is a generic term referring to Unix-like computer operating systems based on the Linux kernel. Their development is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed, both commercially and non-commercially, by anyone distribution is released as an ISO image An ISO image is an archive file of an optical disc in a format defined by the International Organization for Standardization (ISO). This format is supported by many software vendors. ISO image files typically have a file extension of .ISO. The name ISO is taken from the ISO 9660 file system used with CD-ROM media, but an ISO image can also contain onto the distribution developer's own server, this server may become overloaded with demand. Alternative download points allow the total number of download requests to be spread among several servers, maintaining the availability of the distribution. Metalink Metalink is a cross-platform and cross-application open standard/framework/file format for programs that download, including download managers, BitTorrent clients, Web browsers, FTP clients, and P2P programs. For increased convenience, it stores the multiple download locations for a file in a single metafile with the extension .metalink. This is frequently used for automatic load balancing by listing all mirrors.
- As a temporary measure to counterbalance a sudden, temporary increase in traffic Web traffic is the amount of data sent and received by visitors to a web site. It is a large portion of Internet traffic. This is determined by the number of visitors and the number of pages they visit. Sites monitor the incoming and outgoing traffic to see which parts or pages of their site are popular and if there are any apparent trends, such. For example, Slashdotted The Slashdot effect, also known as slashdotting, occurs when a popular website links to a smaller site, causing a massive increase in traffic. This overloads the smaller site, causing it to slow down or even temporarily close. The name stems from the huge influx of web traffic that results from the technology news site Slashdot linking to websites websites will often be mirrored by a few slashdot Slashdot, sometimes abbreviated as /., is a technology-related news website owned by Geeknet, Inc. It features user-submitted and editor-evaluated current affairs news with a "nerdy" slant. Each story on the site has an Internet forum-style comments section attached. The name "Slashdot" is described by the site's owners as & posters until the article is pushed off the front page.
- To increase a site's ranking in a search engine A web search engine is a tool designed to search for information on the World Wide Web. The search results are usually presented in a list and are commonly called hits. The information may consist of web pages, images, information and other types of files. Some search engines also mine data available in databases or open directories. Unlike Web by placing hyperlinks In computing, a hyperlink is a reference to a document that the reader can directly follow. The reference points to another document or to a specific element within a document. Hypertext is text with hyperlinks. Such text is usually viewed with a computer. A software system for viewing and creating hypertext is a hypertext system from each mirror to every other mirror (a technique known as link farming On the World Wide Web, a link farm is any group of web sites that all hyperlink to every other site in the group. Although some link farms can be created by hand, most are created through automated programs and services. A link farm is a form of spamming the index of a search engine . Other link exchange systems are designed to allow individual). This is viewed as unethical Ethics is a branch of philosophy which seeks to address questions about morality, such as what the fundamental semantic, ontological, and epistemic nature of ethics or morality is (meta-ethics), how moral values should be determined (normative ethics), how a moral outcome can be achieved in specific situations (applied ethics), how moral capacity by most search engine administrators and websurfers.
- Rarely, as a form of plagiarism Plagiarism, as defined in the 1995 Random House Compact Unabridged Dictionary, is the "use or close imitation of the language and thoughts of another author and the representation of them as one's own original work." Within academia, plagiarism by students, professors, or researchers is considered academic dishonesty or academic fraud; this is, however, usually pointless, as a website popular enough to be worth plagiarizing will quickly discover the copy as soon as one of their many readers stumbles onto the plagiarized site.
- As a form of raising advertising revenue. Wikipedia Wikipedia is a free, web-based, collaborative, multilingual encyclopedia project supported by the non-profit Wikimedia Foundation. Its name is a portmanteau of the words wiki (a technology for creating collaborative websites, from the Hawaiian word wiki, meaning "quick") and encyclopedia. Wikipedia's 13 million articles (three million in is probably the best example of material released under the GNU Free Documentation License The GNU Free Documentation License is a copyleft license for free documentation, designed by the Free Software Foundation (FSF) for the GNU Project. It is similar to the GNU General Public License, giving readers the rights to copy, redistribute, and modify a work and requires all copies and derivatives to be available under the same license which is then duplicated by other companies which, unlike Wikipedia, then attempt to generate money from advertising, etc. See Wikipedia:Mirrors and forks.
- To serve as a method of circumventing firewalls.
Examples
A good example of mirroring is the well-known SourceForge.net website. The basis of the Sourceforge SourceForge is a web-based source code repository. It acts as a centralized location for software developers to control and manage open source software development. The website is operated by SourceForge, Inc. and runs a version of SourceForge Enterprise Edition, forked from the last open-source version available. As of February 2009[update], the concept is, primarily, the hosting of open-source software Open source software is computer software for which the source code and certain other rights normally reserved for copyright holders are provided under a software license that meets the Open Source Definition or that is in the public domain. This permits users to use, change, and improve the software, and to redistribute it in modified or projects, but secondarily the use of many different locations to achieve one goal: to maintain download availability to the user. Many innovative computer A computer is a machine that manipulates data according to a set of instructions projects host their sites and software on SourceForge, which provides mirrors in several countries In geography, a country is a geographical region. The term is often applied to a political division or the territory of a state, or to a smaller, or former, political division of a geographical region. Usually, but not always, a country coincides with a sovereign territory and is associated with a state, nation and government, from Dublin Dublin is both the largest city and capital of Ireland. It is officially known in Irish as Baile Átha Cliath ([bˠalʲə aːha klʲiəh]) or Áth Cliath ([aːh cliə(ɸ)]); the English name comes from the Irish Dubh Linn meaning "black pool". It is located near the midpoint of Ireland's east coast, at the mouth of the River Liffey and, Ireland Ireland (pronounced /ˈaɪrlənd/ , locally [ˈaɾlənd]; Irish: Éire, pronounced [ˈeːɾʲə] ( listen); Ulster Scots: Airlann, Latin: Hibernia) is the third-largest island in Europe and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islets. To the east of to Tokyo Tokyo , officially Tokyo Metropolis (東京都, Tōkyō-to?), is one of the 47 prefectures of Japan and is located on the eastern side of the main island Honshū. The twenty-three special wards of Tokyo, each governed as a city, cover the area that was once the city of Tokyo in the eastern part of the prefecture, totaling over 8 million people, Japan Japan is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south. The characters which make up Japan's name mean "sun-origin", which.
Examples of even larger mirrored networks include those of the Debian Debian is a computer operating system composed of software packages released as free and open source software especially under the GNU General Public License and other open source licenses. The primary form, Debian GNU/Linux, which uses the Linux kernel and GNU OS tools, is a popular and influential Linux distribution. It is distributed with and FreeBSD FreeBSD is a free Unix-like operating system descended from AT&T UNIX via the Berkeley Software Distribution . It has been characterized as "the unknown giant among free operating systems". It is not a clone of UNIX, but works like UNIX, with UNIX-compliant internals and system APIs. FreeBSD is generally regarded as reliable and software projects. The encyclopedia Wikipedia Wikipedia is a free, web-based, collaborative, multilingual encyclopedia project supported by the non-profit Wikimedia Foundation. Its name is a portmanteau of the words wiki (a technology for creating collaborative websites, from the Hawaiian word wiki, meaning "quick") and encyclopedia. Wikipedia's 13 million articles (three million in is mirrored at numerous locations.
Examples of free file mirroring sites are Uploadjockey, MassMirror, Sharebee.com. They allow anyone to mirror any file.
Software
There are numerous offline browsers The terms online and offline have specific meanings with respect to computer technology and telecommunication. In general, "online" indicates a state of connectivity, while "offline" indicates a disconnected state. In common usage, "online" often refers to the Internet or the World Wide Web that provide automated mirroring of entire sites. Some are oriented towards personal use, which allows browsing from a local copy — this means an initial waiting time but much improved load time for those pages once they're mirrored.
Other programs are intended to be used by public mirror maintainers.
- CVSup
- rsync rsync is a software application for Unix systems which synchronizes files and directories from one location to another while minimizing data transfer using delta encoding when appropriate. An important feature of rsync not found in most similar programs/protocols is that the mirroring takes place with only one transmission in each direction. rsync
Free file mirroring software includes MMup by MassMirror and wget GNU Wget is a computer program that retrieves content from web servers, and is part of the GNU Project. Its name is derived from World Wide Web and get, connotative of its primary function. It currently supports downloading via HTTP, HTTPS, and FTP protocols, the most popular TCP/IP-based protocols used for web browsing, mirror and mirrordir available as add ons for many Linux Linux is a generic term referring to Unix-like computer operating systems based on the Linux kernel. Their development is one of the most prominent examples of free and open source software collaboration; typically all the underlying source code can be used, freely modified, and redistributed, both commercially and non-commercially, by anyone distributions.
See also
- Coral CDN The Coral Content Distribution Network, sometimes called Coral Cache or Coral, is a free peer-to-peer content distribution network. Coral uses the bandwidth of volunteers to mirror web content, often to avoid the Slashdot Effect or to reduce the load on websites in general
- Disk mirroring
- Offline browsing The terms online and offline have specific meanings with respect to computer technology and telecommunication. In general, "online" indicates a state of connectivity, while "offline" indicates a disconnected state. In common usage, "online" often refers to the Internet or the World Wide Web
- Website mirroring software Website mirroring software is software that allows one to download a copy of an entire website to the local hard disk for offline browsing. In effect, the downloaded copy serves as a mirror of the original site
- Wikipedia:Mirrors and forks
Categories: Data management Categories: Computer data | Data | Project management | Information retrieval | Information technology management | Web technology | Black hat search engine optimization
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Videos Now days one of the first things people see in the morning is their own reflection staring back at them in the mirror We get in our cars surrounded by mirrors We watch our DLP big
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Sat, 25 Apr 2009 17:28:27 GM
Can any one provide me the steps or procedure to cofigure raid 1(. mirror. ima...
Q. This is not homework for everybody who said that last time I tried to ask. I am just trying to figure something out on my own and it has NOTHING to do with school. Thank you in advance for answering some or all of these questions: 1) What is the focal length of a 12-inch f/10 mirror?: ___ inches 2) Compute the focal length of the 200-inch, f/3.3 mirror on Mount Palomar.: ___ inches 3) Compute the value of the magnifying power of a 150-inch, f/8 telescope with an eyepiece of one-half-inch focal length.: ___x 4) The larger distance is the: A: Astronomical Unit B: Light-Year I've googled them over and over again or I wouldn't be asking them here. SO thanks alot.
Asked by detroitsports19 - Mon Mar 3 11:17:34 2008 - - 2 Answers - 0 Comments
A. 1) 120 inches (12 times 10). 2) 660 inches (200 times 3.3) 3) 150 at f/8 gives a focal length of 1200 inches. Divide 1200 by 1/2 to get the magnification (2400X) This magnification is generally useless when looking through Earth's atmosphere, no matter how big the objective mirror. 4) the light year. An AU is 93 million miles. The light year is 5.9 trillion miles.
Answered by david_bowman_sc - Mon Mar 3 11:50:46 2008
