file system

Definition of file system in The Network Encyclopedia.

What is File System?

Any technology for organizing, storing, and locating data on a system or network. The file system for a computing platform defines the method by which the operating system stores, locates, and accesses files on its hard disk subsystem.

How it works

File systems usually have a hierarchical structure consisting of a series of nested directories for storing files. Each directory can contain files, other subdirectories, or both. The top of the file system is called the root, and the various directories are its branches. The file system thus forms a tree.

Graphic F-12. A hierarchical file system.

File systems include conventions for the type and the maximum number of characters that can be used to name a file. A file can be located in the file system by specifying its absolute path - that is, its path starting from the root and traversing through the directory structure until the file is reached. Using graphical user interface (GUI) or command-line tools, files can be located, copied, moved, and deleted. Microsoft Windows Explorer is an example of a GUI tool that shows the hierarchical structure of the file system on a Windows-based machine. File systems can incorporate technologies for marking files with attributes such as hidden and read-only. Some file systems allow you to compress files, and some allow you to specify file system quotas for users.

File systems can generally be classified into two types, depending on where the stored resources are located:

  • Local file systems:
    These systems are part of the operating system and manage locally attached storage devices such as disk drives and removable drives. Portions of local file systems can be shared to allow users on the network to access specific files, but users generally need to know the name or location of the share in order to access it.

     

  • Distributed file systems:
    These systems are used to combine shared portions of local file systems on many different machines into a single network-wide hierarchical file system. Distributed file systems allow shared network resources located all over the network to appear as though they are located on a single “superserver,” and simplify the process of users locating and accessing shared network resources.

     

Examples of common file systems include the following:

  • The file allocation table (FAT) file system for MS-DOS-based and Windows-based computers
  • The NTFS file system for Windows NT and Windows 2000
  • The Distributed file system (Dfs) for Windows NT and Windows 2000
  • The standard hierarchical UNIX file system
  • Sun’s distributed Network File System (NFS) for UNIX platforms