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Virtual File System
A virtual file system (VFS) or virtual filesystem switch is an abstract layer on top of a more concrete file system. The purpose of a VFS is to allow client applications to access different types of concrete file systems in a uniform way. A VFS can, for example, be used to access local and network storage devices transparently without the client application noticing the difference. It can be used to bridge the differences in Windows, classic Mac OS/macOS and Unix filesystems, so that applications can access files on local file systems of those types without having to know what type of file system they are accessing. A VFS specifies an interface (or a "contract") between the kernel and a concrete file system. Therefore, it is easy to add support for new file system types to the kernel simply by fulfilling the contract. The terms of the contract might change incompatibly from release to release, which would require that concrete file system support be recompiled, and possibly mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
File System
In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one large body of data with no way to tell where one piece of data stopped and the next began, or where any piece of data was located when it was time to retrieve it. By separating the data into pieces and giving each piece a name, the data are easily isolated and identified. Taking its name from the way a paper-based data management system is named, each group of data is called a "file". The structure and logic rules used to manage the groups of data and their names is called a "file system." There are many kinds of file systems, each with unique structure and logic, properties of speed, flexibility, security, size and more. Some file systems have been designed to be used for specific applications. For example, the ISO 9660 file system is designe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Heidemann
John Heidemann is an engineer at the USC Information Sciences Institute in Marina del Rey, California. He was named a Fellow of the Institute of Electrical and Electronics Engineers (IEEE) in 2014 for his contributions to sensor networks, internet measurement, and simulation A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the s ...s. He has authored more than two hundred and fifty scholarly papers in these fields. His research has been supported by the American National Science Foundation, among others. John Heidemann was very active in the field of sensor networks in the 2000s. With Nirupama Bulusu and Deborah Estrin, he developed the first wireless, range-free localization system for wireless sensor networks. With Wei Ye and Deborah Estrin he developed S-MAC, an early energy-conserving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OpenSolaris
OpenSolaris () is a discontinued open-source computer operating system based on Solaris and created by Sun Microsystems. It was also, perhaps confusingly, the name of a project initiated by Sun to build a developer and user community around the eponymous operating system software. OpenSolaris is a descendant of the UNIX System V Release 4 (SVR4) code base developed by Sun and AT&T in the late 1980s and is the only version of the System V variant of UNIX available as open source. OpenSolaris was developed as a combination of several software ''consolidations'' that were open sourced starting with Solaris 10. It includes a variety of free software, including popular desktop and server software. After Oracle’s acquisition of Sun Microsystems in 2010, Oracle discontinued development of OpenSolaris in house, pivoting to focus exclusively on the development of the proprietary Solaris Express (now Oracle Solaris). Prior to Oracle's close-sourcing Solaris, a group of former O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FreeBSD
FreeBSD is a free and open-source Unix-like operating system descended from the Berkeley Software Distribution (BSD), which was based on Research Unix. The first version of FreeBSD was released in 1993. In 2005, FreeBSD was the most popular open-source BSD operating system, accounting for more than three-quarters of all installed and permissively licensed BSD systems. FreeBSD has similarities with Linux, with two major differences in scope and licensing: FreeBSD maintains a complete system, i.e. the project delivers a kernel, device drivers, userland utilities, and documentation, as opposed to Linux only delivering a kernel and drivers, and relying on third-parties for system software; FreeBSD source code is generally released under a permissive BSD license, as opposed to the copyleft GPL used by Linux. The FreeBSD project includes a security team overseeing all software shipped in the base distribution. A wide range of additional third-party applications may be installe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NetBSD
NetBSD is a free and open-source Unix operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was forked. It continues to be actively developed and is available for many platforms, including servers, desktops, handheld devices, and embedded systems. The NetBSD project focuses on code clarity, careful design, and portability across many computer architectures. Its source code is publicly available and permissively licensed. History NetBSD was originally derived from the 4.3BSD-Reno release of the Berkeley Software Distribution from the Computer Systems Research Group of the University of California, Berkeley, via their Net/2 source code release and the 386BSD project. The NetBSD project began as a result of frustration within the 386BSD developer community with the pace and direction of the operating system's development. The four founders of the NetBSD project, Chris Demetriou, Theo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Userland (computing)
A modern computer operating system usually segregates virtual memory into user space and kernel space. Primarily, this separation serves to provide memory protection and hardware protection from malicious or errant software behaviour. Kernel space is strictly reserved for running a privileged operating system kernel, kernel extensions, and most device drivers. In contrast, user space is the memory area where application software and some drivers execute. Overview The term user space (or userland) refers to all code that runs outside the operating system's kernel. User space usually refers to the various programs and library (computing), libraries that the operating system uses to interact with the kernel: software that performs input/output, manipulates file system objects, application software, etc. Each user space process (computing), process normally runs in its own virtual memory space, and, unless explicitly allowed, cannot access the memory of other processes. This is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filesystem In Userspace
Filesystem in Userspace (FUSE) is a software interface for Unix and Unix-like computer operating systems that lets non-privileged users create their own file systems without editing kernel code. This is achieved by running file system code in user space while the FUSE module provides only a bridge to the actual kernel interfaces. FUSE is available for Linux, FreeBSD, OpenBSD, NetBSD (as puffs), OpenSolaris, Minix 3, macOS, and Windows. FUSE is free software originally released under the terms of the GNU General Public License and the GNU Lesser General Public License. History The FUSE system was originally part of ''AVFS'' (''A Virtual Filesystem''), a filesystem implementation heavily influenced by the translator concept of the GNU Hurd. It superseded Linux Userland Filesystem, and provided a translational interface using in libfuse1. FUSE was originally released under the terms of the GNU General Public License and the GNU Lesser General Public License, later also reimple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Installable File System
The Installable File System (IFS) is a filesystem API in MS-DOS/PC DOS 4.x, IBM OS/2 and Microsoft Windows that enables the operating system to recognize and load drivers for file systems. History When IBM and Microsoft were co-developing OS/2, they realized that the FAT file system did not offer some of the features modern OSes would require, and Microsoft began developing the High Performance File System (HPFS), codenamed ''Pinball''. Instead of coding it inside the kernel, as FAT was, Microsoft developed a "driver-based" filesystem API that could allow them and other developers to add new filesystems to the kernel without needing to modify it. When Microsoft stopped working on OS/2, IBM continued using the IFS interface and Microsoft implemented a similar one in Windows NT. Implementations IFS in DOS 4.x IFS in OS/2 The IFS provided a basic and powerful interface for programming filesystems. It was introduced in 1989 in OS/2 1.20, along with the HPFS filesystem. File ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OS/2
OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 relative to Microsoft's new Windows 3.1 operating environment, the two companies severed the relationship in 1992 and OS/2 development fell to IBM exclusively. The name stands for "Operating System/2", because it was introduced as part of the same generation change release as IBM's " Personal System/2 (PS/2)" line of second-generation personal computers. The first version of OS/2 was released in December 1987 and newer versions were released until December 2001. OS/2 was intended as a protected-mode successor of PC DOS. Notably, basic system calls were modeled after MS-DOS calls; their names even started with "Dos" and it was possible to create "Family Mode" applications – text mode applications that could work on both systems. Be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which includes the kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name "GNU/Linux" to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian, Fedora Linux, and Ubuntu, the latter of which itself consists of many different distributions and modifications, including Lubuntu and Xubuntu. Commercial distributions include Red Hat Enterprise Linux and SUSE Linux Enterprise. Desktop Linux distributions include a windowing system such as X11 or Wayland, and a desktop environment such as GNOME or KDE Plasma. Distributions intended for ser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultrix
Ultrix (officially all-caps ULTRIX) is the brand name of Digital Equipment Corporation's (DEC) discontinued native Unix operating systems for the PDP-11, VAX, MicroVAX and DECstations. History The initial development of Unix occurred on DEC equipment, notably DEC PDP-7 and PDP-11 (Programmable Data Processor) systems. Later DEC computers, such as their VAX, also offered Unix. The first port to VAX, UNIX/32V, was finished in 1978, not long after the October 1977 announcement of the VAX, for which – at that time – DEC only supplied its own proprietary operating system, VMS. DEC's Unix Engineering Group (UEG) was started by Bill Munson with Jerry Brenner and Fred Canter, both from DEC's Customer Service Engineering group, Bill Shannon (from Case Western Reserve University), and Armando Stettner (from Bell Labs). Other later members of UEG included Joel Magid, Bill Doll, and Jim Barclay recruited from DEC's marketing and product management groups. Under Canter's direction, UEG ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
System V Release 3
Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, and 4. System V Release 4 (SVR4) was commercially the most successful version, being the result of an effort, marketed as ''Unix System Unification'', which solicited the collaboration of the major Unix vendors. It was the source of several common commercial Unix features. System V is sometimes abbreviated to SysV. , the AT&T-derived Unix market is divided between four System V variants: IBM's AIX, Hewlett Packard Enterprise's HP-UX and Oracle's Solaris, plus the free-software illumos forked from OpenSolaris. Overview Introduction System V was the successor to 1982's UNIX System III. While AT&T developed and sold hardware that ran System V, most customers ran a version from a reseller, based on AT&T's reference implementation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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