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Runlevel
A runlevel is a mode of operation in the computer operating systems that implements Unix System V-style initialization. Conventionally, seven runlevels exist, numbered from zero to six. ''S'' is sometimes used as a synonym for one of the levels. Only one runlevel is executed on startup; run levels are not executed one after another (i.e. only runlevel 2, 3, or 4 is executed, not more of them sequentially or in any other order). A runlevel defines the state of the machine after boot. Different runlevels are typically assigned (not necessarily in any particular order) to the single-user mode, multi-user mode without network services started, multi-user mode with network services started, system shutdown, and system reboot system states. The exact setup of these configurations varies between operating systems and Linux distributions. For example, runlevel 4 might be a multi-user GUI no-server configuration on one distribution, and nothing on another. Runlevels commonly follow the gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Init
In Unix-based computer operating systems, init (short for ''initialization'') is the first process started during booting of the computer system. Init is a daemon process that continues running until the system is shut down. It is the direct or indirect ancestor of all other processes and automatically adopts all orphaned processes. Init is started by the kernel during the booting process; a kernel panic will occur if the kernel is unable to start it. Init is typically assigned process identifier 1. In Unix systems such as System III and System V, the design of init has diverged from the functionality provided by the init in Research Unix and its BSD derivatives. Up until recently, most Linux distributions employed a traditional init that was somewhat compatible with System V, while some distributions such as Slackware use BSD-style startup scripts, and others such as Gentoo have their own customized versions. Since then, several additional init implementatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sysvinit
In Unix-based computer operating systems, init (short for ''initialization'') is the first process started during booting of the computer system. Init is a daemon process that continues running until the system is shut down. It is the direct or indirect ancestor of all other processes and automatically adopts all orphaned processes. Init is started by the kernel during the booting process; a kernel panic will occur if the kernel is unable to start it. Init is typically assigned process identifier 1. In Unix systems such as System III and System V, the design of init has diverged from the functionality provided by the init in Research Unix and its BSD derivatives. Up until recently, most Linux distributions employed a traditional init that was somewhat compatible with System V, while some distributions such as Slackware use BSD-style startup scripts, and others such as Gentoo have their own customized versions. Since then, several additional init implementations have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single-user Mode
Single-user mode is a mode in which a multiuser computer operating system boots into a single superuser. It is mainly used for maintenance of multi-user environments such as network servers. Some tasks may require exclusive access to shared resources, for example running fsck on a network share. This mode can also be used for security purposes network services are not run, eliminating the possibility of outside interference. On some systems a lost superuser password can be changed by switching to single-user mode, but not asking for the password in such circumstances is viewed as a security vulnerability. Unix family Unix-like operating systems provide single-user mode functionality either through the System V-style runlevels, BSD-style boot-loader options, or other boot-time options. The run-level is usually changed using the init command, runlevel 1 or S will boot into single-user mode. Boot-loader options can be changed during startup before the execution of the ker ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Single User Mode
Single-user mode is a mode in which a multiuser computer operating system boots into a single superuser. It is mainly used for maintenance of multi-user environments such as network servers. Some tasks may require exclusive access to shared resources, for example running fsck on a network share. This mode can also be used for security purposes network services are not run, eliminating the possibility of outside interference. On some systems a lost superuser password can be changed by switching to single-user mode, but not asking for the password in such circumstances is viewed as a security vulnerability. Unix family Unix-like operating systems provide single-user mode functionality either through the System V-style runlevels, BSD-style boot-loader options, or other boot-time options. The run-level is usually changed using the init command, runlevel 1 or S will boot into single-user mode. Boot-loader options can be changed during startup before the execution of the kernel. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Systemd
systemd is a software suite that provides an array of system components for Linux operating systems. Its main aim is to unify service configuration and behavior across Linux distributions; Its primary component is a "system and service manager"—an init system used to bootstrap user space and manage user processes. It also provides replacements for various daemons and utilities, including device management, login management, network connection management, and event logging. The name ''systemd'' adheres to the Unix convention of naming daemons by appending the letter ''d''. It also plays on the term " System D", which refers to a person's ability to adapt quickly and improvise to solve problems. Since 2015, the majority of Linux distributions have adopted systemd, having replaced other init systems such as SysV init. It has been praised by developers and users of distributions that adopted it for providing a stable, fast out-of-the-box solution for issues that had exist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multi-user
Multi-user software is computer software that allows access by multiple users of a computer. Time-sharing systems are multi-user systems. Most batch processing systems for mainframe computers may also be considered "multi-user", to avoid leaving the CPU idle while it waits for I/O operations to complete. However, the term " multitasking" is more common in this context. An example is a Unix or Unix-like system where multiple remote users have access (such as via a serial port or Secure Shell) to the Unix shell prompt at the same time. Another example uses multiple X Window sessions spread across multiple terminals powered by a single machine - this is an example of the use of thin client. Similar functions were also available in a variety of non-Unix-like operating systems, such as Multics, VM/CMS, OpenVMS, MP/M, Concurrent CP/M, Concurrent DOS, FlexOS, Multiuser DOS, REAL/32, OASIS, THEOS, PC-MOS, TSX-32 and VM/386. Some multi-user operating systems such as Windows versi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Remote File System
Remote File Sharing (RFS) is a Unix operating system component for sharing resources, such as files, devices, and file system directories, across a network, in a network-independent manner, similar to a distributed file system. It was developed at Bell Laboratories of AT&T in the 1980s, and was first delivered with UNIX System V Release 3 (SVR3). RFS relied on the STREAMS Transport Provider Interface feature of this operating system. It was also included in UNIX System V Release 4, but as that also included the Network File System (NFS) which was based on TCP/IP and more widely supported in the computing industry, RFS was little used. Some licensees of AT&T UNIX System V Release 4 did not include RFS support in SVR4 distributions, and Sun Microsystems removed it from Solaris 2.4. Features The basic application architecture of RFS is the client–server model, in which a participating host may be a server as well as a client, simultaneously. It was based on different design decisions, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slackware Linux
Slackware is a Linux distribution created by Patrick Volkerding in 1993. Originally based on Softlanding Linux System, Slackware has been the basis for many other Linux distributions, most notably the first versions of SUSE Linux distributions, and is the oldest distribution that is still maintained. Slackware aims for design stability and simplicity and to be the most "Unix-like" Linux distribution. It makes as few modifications as possible to software packages from upstream and tries not to anticipate use cases or preclude user decisions. In contrast to most modern Linux distributions, Slackware provides no graphical installation procedure and no automatic dependency resolution of software packages. It uses plain text files and only a small set of shell scripts for configuration and administration. Without further modification it boots into a command-line interface environment. Because of its many conservative and simplistic features, Slackware is often considered to be most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gentoo Linux
Gentoo Linux (pronounced ) is a Linux distribution built using the Portage package management system. Unlike a binary software distribution, the source code is compiled locally according to the user's preferences and is often optimized for the specific type of computer. Precompiled binaries are available for some larger packages or those with no available source code. Gentoo Linux was named after the gentoo penguin, the fastest swimming species of penguin. The name was chosen to reflect the potential speed improvements of machine-specific optimization, which is a major feature of Gentoo. Gentoo package management is designed to be modular, portable, easy to maintain, and flexible. Gentoo describes itself as a meta-distribution because of its adaptability, in that the majority of users have configurations and sets of installed programs which are unique to the system and the applications they use. History Gentoo Linux was initially created by Daniel Robbins as the ''Enoch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debian GNU/Linux
Debian (), also known as Debian GNU/Linux, is a Linux distribution composed of free and open-source software, developed by the community-supported Debian Project, which was established by Ian Murdock on August 16, 1993. The first version of Debian (0.01) was released on September 15, 1993, and its first stable version (1.1) was released on June 17, 1996. The Debian Stable branch is the most popular edition for personal computers and servers. Debian is also the basis for many other distributions, most notably Ubuntu. Debian is one of the oldest operating systems based on the Linux kernel. The project is coordinated over the Internet by a team of volunteers guided by the Debian Project Leader and three foundational documents: the Debian Social Contract, the Debian Constitution, and the Debian Free Software Guidelines. New distributions are updated continually, and the next candidate is released after a time-based freeze. Since its founding, Debian has been developed openly an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for efficient use of the system and may also include accounting software for cost allocation of Scheduling (computing), processor time, mass storage, printing, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer from cellular phones and video game consoles to web servers and supercomputers. The dominant general-purpose personal computer operating system is Microsoft Windows with a market share of aroun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
