Virtual file system

from Wikipedia, the free encyclopedia

A virtual file system (English virtual file system and also called VFS for short ) is an abstraction layer above specific file systems .

more details

A VFS layer provides applications with a uniform API to access different file systems.

This serves as a general interface and hides various local file systems as well as access to remote directories and files. The VFS maintains an entry for each open file ( called v-node )

  • either the local file descriptor ( i-node )
  • or a global NFS descriptor ( r-node )

The dynamic mounting (and unmounting) of imported directories is carried out by a special program, the automounter.

A VFS layer (also called VFS switch ) is available in Linux , BSD -based operating systems, in the KDE desktop ( Kio ), Gnome desktop ( GVFS ) and in the Jakarta project of the Apache Software Foundation .

Variant of meaning

On the part of users and developers is the concept of the virtual file system for a set of data that an ordinary file system like (with on a disk physically stored files appear), but there are not, but are provided by special system components as required (see. " everything is a file ”).


Well-known examples are procfs and sysfs . Furthermore, FUSE offers the possibility of programming virtual file systems without having to intervene in the operating system software, although this possibility is already included in the system concept of GNU Hurd .

Web links

supporting documents

  1. GNU Hurd / hurd / translator (English)