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Vkernel
A virtual kernel architecture (vkernel) is an operating system virtualisation paradigm where kernel code can be compiled to run in the user space, for example, to ease debugging of various kernel-level components, in addition to general-purpose virtualisation and compartmentalisation of system resources. It is used by DragonFly BSD in its vkernel implementation since DragonFly 1.7, having been first revealed in , and first released in the stable branch with DragonFly 1.8 in . The long-term goal, in addition to easing kernel development, is to make it easier to support internet-connected computer clusters without compromising local security. Similar concepts exist in other operating systems as well; in Linux, a similar virtualisation concept is known as user-mode Linux; whereas in NetBSD since the summer of 2007, it has been the initial focus of the rump kernel infrastructure. The ''virtual kernel'' concept is nearly the exact opposite of the ''unikernel'' concept — with ''vkern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OS-level Virtualisation
OS-level virtualization is an operating system (OS) paradigm in which the kernel allows the existence of multiple isolated user space instances, called ''containers'' ( LXC, Solaris containers, Docker, Podman), ''zones'' (Solaris containers), ''virtual private servers'' (OpenVZ), ''partitions'', ''virtual environments'' (VEs), ''virtual kernels'' (DragonFly BSD), or ''jails'' (FreeBSD jail or chroot jail). Such instances may look like real computers from the point of view of programs running in them. A computer program running on an ordinary operating system can see all resources (connected devices, files and folders, network shares, CPU power, quantifiable hardware capabilities) of that computer. However, programs running inside of a container can only see the container's contents and devices assigned to the container. On Unix-like operating systems, this feature can be seen as an advanced implementation of the standard chroot mechanism, which changes the apparent root folder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DragonFly BSD
DragonFly BSD is a free and open-source Unix-like operating system forked from FreeBSD 4.8. Matthew Dillon, an Amiga developer in the late 1980s and early 1990s and FreeBSD developer between 1994 and 2003, began working on DragonFly BSD in June 2003 and announced it on the FreeBSD mailing lists on 16 July 2003. Dillon started DragonFly in the belief that the techniques adopted for threading and symmetric multiprocessing in FreeBSD 5 would lead to poor performance and maintenance problems. He sought to correct these anticipated problems within the FreeBSD project. Due to conflicts with other FreeBSD developers over the implementation of his ideas, his ability to directly change the codebase was eventually revoked. Despite this, the DragonFly BSD and FreeBSD projects still work together, sharing bug fixes, driver updates, and other improvements. Intended as the logical continuation of the FreeBSD 4.x series, DragonFly has diverged significantly from FreeBSD, implementing lig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FreeBSD Jail
The jail mechanism is an implementation of FreeBSD's OS-level virtualisation that allows system administrators to partition a FreeBSD-derived computer system into several independent mini-systems called ''jails'', all sharing the same kernel, with very little overhead. It is implemented through a system call, jail(2), as well as a userland utility, jail(8), plus, depending on the system, a number of other utilities. The functionality was committed into FreeBSD in 1999 by Poul-Henning Kamp after some period of production use by a hosting provider, and was first released with FreeBSD 4.0, thus being supported on a number of FreeBSD descendants, including DragonFly BSD, to this day. History The need for the FreeBSD jails came from a small shared-environment hosting provider's (R&D Associates, Inc.'s owner, Derrick T. Woolworth) desire to establish a clean, clear-cut separation between their own services and those of their customers, mainly for security and ease of administrationjail(8 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BSD Software
The Berkeley Software Distribution or Berkeley Standard Distribution (BSD) is a discontinued operating system based on Research Unix, developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley. The term "BSD" commonly refers to its open-source descendants, including FreeBSD, OpenBSD, NetBSD, and DragonFly BSD. BSD was initially called Berkeley Unix because it was based on the source code of the original Unix developed at Bell Labs. In the 1980s, BSD was widely adopted by workstation vendors in the form of proprietary Unix variants such as DEC Ultrix and Sun Microsystems SunOS due to its permissive licensing and familiarity to many technology company founders and engineers. Although these proprietary BSD derivatives were largely superseded in the 1990s by UNIX SVR4 and OSF/1, later releases provided the basis for several open-source operating systems including FreeBSD, OpenBSD, NetBSD, DragonFly BSD, Darwin, and TrueOS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prentice Hall Professional
Prentice Hall was an American major educational publisher owned by Savvas Learning Company. Prentice Hall publishes print and digital content for the 6–12 and higher-education market, and distributes its technical titles through the Safari Books Online e-reference service. History On October 13, 1913, law professor Charles Gerstenberg and his student Richard Ettinger founded Prentice Hall. Gerstenberg and Ettinger took their mothers' maiden names, Prentice and Hall, to name their new company. Prentice Hall became known as a publisher of trade books by authors such as Norman Vincent Peale; elementary, secondary, and college textbooks; loose-leaf information services; and professional books. Prentice Hall acquired the training provider Deltak in 1979. Prentice Hall was acquired by Gulf+Western in 1984, and became part of that company's publishing division Simon & Schuster. S&S sold several Prentice Hall subsidiaries: Deltak and Resource Systems were sold to National Education ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
InformIT (publisher)
Pearson Education is a British-owned education publishing and assessment service to schools and corporations, as well for students directly. Pearson owns educational media brands including Addison–Wesley, Peachpit, Prentice Hall, eCollege, Longman, Scott Foresman, and others. Pearson is part of Pearson plc, which formerly owned the ''Financial Times''. It claims to have been formed in 1840, with the current incarnation of the company created when Pearson plc purchased the education division of Simon & Schuster (including Prentice Hall and Allyn & Bacon) from Viacom (2005–2019), Viacom and merged it with its own education division, Addison-Wesley Longman, to form Pearson Education. Pearson Education was rebranded to Pearson in 2011 and split into an International and a North American division. Although Pearson generates approximately 60 percent of its sales in North America, it operates in more than 70 countries. Pearson International is headquartered in London, and maintai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KernelTrap
KernelTrap was a computing news website which covered topics related to the development of free and open source operating system kernels, and especially, the Linux kernel. News stories usually consisted of a summary of a recent discussion from a development mailing list (Linux kernel mailing list) followed by the entire contents of several messages from the discussion. Each story had moderated threaded discussion attached to it. The site also included a forum for general discussion of computing topics. The site used the Drupal content management system. Kerneltrap was hosted by the Oregon State University Open Source Lab from May 2005. The site was operated by Jeremy Andrews. Current status The site has not been active since 12 April 2010, only 12 days after it became active again after a full year without any news items (except a note about upgrading the site engine, Drupal). Since May of 2021, the kerneltrap.org domain points to a lengthy KernelTrap-style interview with Linus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2006 Software
6 (six) is the natural number following 5 and preceding 7. It is a composite number and the smallest perfect number. In mathematics Six is the smallest positive integer which is neither a square number nor a prime number; it is the second smallest composite number, behind 4; its proper divisors are , and . Since 6 equals the sum of its proper divisors, it is a perfect number; 6 is the smallest of the perfect numbers. It is also the smallest Granville number, or \mathcal-perfect number. As a perfect number: *6 is related to the Mersenne prime 3, since . (The next perfect number is 28 (number), 28.) *6 is the only even perfect number that is not the sum of successive odd cubes. *6 is the root of the 6-aliquot tree, and is itself the aliquot sum of only one other number; the square number, . Six is the only number that is both the sum and the product of three consecutive positive numbers. Unrelated to 6's being a perfect number, a Golomb ruler of length 6 is a "perfect ruler". Si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matthew Dillon
Matthew Dillon (born 1966) is an American software engineer known for Amiga software, contributions to FreeBSD and for starting and leading the DragonFly BSD project since 2003. Biography Dillon studied electronic engineering and computer science at the University of California, Berkeley, where he first became involved with BSD in 1985. He also became known for his Amiga programming, his C compiler DICE and his work on the Linux kernel. He founded and worked at Best Internet from 1994 until 1997, contributing to FreeBSD in that time. His "Diablo" internet news transit program was very popular with many ISPs. In 1997, Dillon gained commit access to the FreeBSD code and heavily contributed to the virtual memory subsystem, amongst other contributions. Concerned with problems he saw in the direction FreeBSD 5.x was headed in regards to concurrency, and coupled with the fact that Dillon's access to the FreeBSD source code repository was revoked due to a falling-out with other Fre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Architecture
In computer engineering, computer architecture is a description of the structure of a computer system made from component parts. It can sometimes be a high-level description that ignores details of the implementation. At a more detailed level, the description may include the instruction set architecture design, microarchitecture design, logic design, and implementation. History The first documented computer architecture was in the correspondence between Charles Babbage and Ada Lovelace, describing the analytical engine. When building the computer Z1 in 1936, Konrad Zuse described in two patent applications for his future projects that machine instructions could be stored in the same storage used for data, i.e., the stored-program concept. Two other early and important examples are: * John von Neumann's 1945 paper, First Draft of a Report on the EDVAC, which described an organization of logical elements; and *Alan Turing's more detailed ''Proposed Electronic Calculator'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mmap
In computing, mmap(2) is a POSIX-compliant Unix system call that maps files or devices into memory. It is a method of memory-mapped file I/O. It implements demand paging because file contents are not immediately read from disk and initially use no physical RAM at all. The actual reads from disk are performed after a specific location is accessed, in a lazy manner. After the mapping is no longer needed, the pointers must be unmapped with munmap(2). Protection information—for example, marking mapped regions as executable—can be managed using mprotect(2), and special treatment can be enforced using madvise(2). In Linux, macOS and the BSDs, mmap can create several types of mappings. Other operating systems may only support a subset of these; for example, shared mappings may not be practical in an operating system without a global VFS or I/O cache. History The original design of memory-mapped files came from the TOPS-20 operating system. mmap and associated systems calls were des ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Free Software Programmed In C
Free may refer to: Concept * Freedom, having the ability to do something, without having to obey anyone/anything * Freethought, a position that beliefs should be formed only on the basis of logic, reason, and empiricism * Emancipate, to procure political rights, as for a disenfranchised group * Free will, control exercised by rational agents over their actions and decisions * Free of charge, also known as gratis. See Gratis vs libre. Computing * Free (programming), a function that releases dynamically allocated memory for reuse * Free format, a file format which can be used without restrictions * Free software, software usable and distributable with few restrictions and no payment * Freeware, a broader class of software available at no cost Mathematics * Free object ** Free abelian group ** Free algebra ** Free group ** Free module ** Free semigroup * Free variable People * Free (surname) * Free (rapper) (born 1968), or Free Marie, American rapper and media personal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
