A file system (or filesystem) is an abstraction to store, retrieve and update a set of files. The term also identifies the data structures specified by some of those abstractions, which are designed to organize multiple files as a single stream of bytes, and the network protocols specified by some other of those abstractions, which are designed to allow files on a remote machine to be accessed. By extension, the term also identifies software or firmware components that implement the abstraction (i.e. that actually access the data source on behalf of other software or firmware that uses those components).
The file system manages access to the data and the metadata of the files, and manages the available space of the device(s) which contain it. Ensuring reliability is a major responsibility of a file system. A file system organizes data in an efficient manner, and may be tuned to the characteristics of the backing device.
Some file systems are used on data storage devices, to maintain the locations of the files on the device (which is seen as a stream of bytes). Others provide access to files residing on a server, by acting as clients for a network protocol (e.g. NFS, SMB, or 9P clients). Others provide access to data that is not stored on a persistent device, and/or may be computed on request (e.g. procfs). This is distinguished from a directory service and registry.
Famous quotes containing the words file and/or system:
“While waiting to get married, several forms of employment were acceptable. Teaching kindergarten was for those girls who stayed in school four years. The rest were secretaries, typists, file clerks, or receptionists in insurance firms or banks, preferably those owned or run by the family, but respectable enough if the boss was an upstanding Christian member of the community.”
—Barbara Howar (b. 1934)
“A heresy can spring only from a system that is in full vigor.”
—Eric Hoffer (19021983)