Root directory

from Wikipedia, the free encyclopedia
Typical root directory on Linux

The root directory , the root , the root directory in short, the root , or fachsprachlich (the) Root (directory), English root (directory) , the top level of a tree-like data structure . The most prominent example of a tree in the field of computer science is usually found in the form of file systems on data carriers. Every operating system has a directory that is not contained in any other directory, some systems have such a directory per partition or volume , i.e. several. Such a directory represents (in each case) the starting point for the entire directory tree - it thus forms the head of every directory structure . Directory trees “grow” from top to bottom, the root is always shown at the top.

Which and how many root directories an operating system uses depends on the one hand on the operating system itself and on the file systems used.

Unix and Unixoids

A Unix and Unix - like operating system uses a global root directory and thus a central directory structure with a simple identifier/( Slash ) is. The entire directory structure below/is also known as the Unix file system. Unix-like systems follow the paradigm Everything is a file ('Everything is a file'), so that this directory structure not only manages binary and text files as well as (sub) directories and symbolic links , but also device files of various types. A volume (which often corresponds to a partition) is used for the global root directory, the so-called root partition (or volume ) /, below which further partitions (or volumes ) are mounted ("mounted") . Almost every partition - more precisely: the file system it contains - can be accessed via any subdirectory that serves as a mount point. mountIf the command is called without parameters, it outputs a list of all mounted volumes and the mount points used. The file sets in many Unix-like operating systems define the configuration of the partitions to be used for the operating system, so this when you start to be automatically mounted. /etc/fstab

The root directory, English root directory corresponds with the path /to the starting point of the "Unix file system" - within the volume -Verzeichnisses, however, according to the Filesystem Hierarchy Standard , a user directory of the root account exists, the with /rootis called similar, and thus poses a likelihood of confusion.


CP / M , DOS and Windows , as well as some other operating systems , usually assign the letter to the partition or volume from which they are booting (also called “system partition”)A.for floppy disks andC.for hard drives too, followed by a colon. The full path of the root directory is then e.g. B. C:\, where the drive letter C:forms the starting point. Other partitions (the same volume, or other media) will each be assigned a letter in alphabetical order, so that all volumes each with their own root directory: D:\, E:\etc. (The drive letter A:and B:were traditionally used for floppy drives reserved, but others can volumes are assigned.) Since Windows XP , volumes , for example NTFS partitions, can also - as with Unix-like operating systems - be mounted in the directory structure of the system partition or any other already existing drive letter (under its root directory) (C: \ Other_Partition \). Conversely, it is also possible to assign a free drive letter to any folder: The folderC: \ Documents and Settings \ [username] \ Music \can then z. B. asM: \can be made usable. The external command for this SUBSThas been available since PC DOS / MS-DOS 3.1 (see list of DOS command line commands ). Since all drive letters are managed and recorded internally by the operating system, it does not matter what type of drive letter a drive letter is, for application programs as well as for the user. For the user in a graphical environment , only a list of available "drives" is presented (meaning drive letters, but not directories as mount points). B. can be displayed virtually under Windows under “My PC”, “My Computer” or “This PC”. This also shows other devices and network addresses, but this does not correspond to an all-encompassing root directory as with Unix.

Individual evidence

  1. Aeleen fresh: Unix system administration . O'Reilly Germany, 2003, 2: The Unix Philosophy, p. 66, footnote 13 ( full text in Google Book Search): “The term file system thus refers on the one hand to the higher-level directory tree of the system, which includes all hard drive partitions of the system that the user can access (as in» the Unix file system «), On the other hand to the files and directories on the individual hard disk partitions (as in“ Setting up a file system on a hard disk partition ”or“ Mounting the user file system ”). Only from the context does it become clear which of the two meanings of the term is meant. "