The Be File System (BFS) is the native

file system In computing, file system or filesystem (often abbreviated to fs) is a method and data structure that the operating system uses to control how data is stored and retrieved. Without a file system, data placed in a storage medium would be one larg ...

for the

BeOS BeOS is an operating system for personal computers first developed by Be Inc. in 1990. It was first written to run on BeBox hardware. BeOS was positioned as a multimedia platform that could be used by a substantial population of desktop users an ...

. In the Linux kernel, it is referred to as "BeFS" to avoid confusion with

Boot File System The Boot File System (named BFS on Linux, but BFS also refers to the Be File System) was used on UnixWare to store files necessary to its boot process. It does not support directories, and only allows contiguous allocation for files, to make it ...

. BFS was developed by

Dominic Giampaolo Dominic P. Giampaolo is a software developer who helped develop the Be File System for the Be Operating System (BeOS) and currently works at Apple Inc. After graduating from Lewiston High School in Lewiston, Maine in 1987, he started studying po ...

and Cyril Meurillon over a ten-month period, starting in September 1996, to provide BeOS with a modern

64-bit In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit CPUs and ALUs are those that are based on processor registers, address buses, or data buses of that size. A ...

-capable

journaling file system A journaling file system is a file system that keeps track of changes not yet committed to the file system's main part by recording the goal of such changes in a data structure known as a " journal", which is usually a circular log. In the even ...

. It is

case-sensitive In computers, case sensitivity defines whether uppercase and lowercase letters are treated as distinct (case-sensitive) or equivalent (case-insensitive). For instance, when users interested in learning about dogs search an e-book, "dog" and "Dog" a ...

and capable of being used on

floppy disk A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined ...

hard disk A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magn ...

s and read-only media such as

CD-ROM A CD-ROM (, compact disc read-only memory) is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data. Computers can read—but not write or erase—CD-ROMs. Some CDs, called enhanced CDs, hold both com ...

s. However, its use on small removable media is not advised, as the file-system headers consume from 600 KB to 2 MB, rendering floppy disks virtually useless. Like its predecessor, OFS (Old Be File System, written by

Benoit Schillings Benoit Schillings is a Belgian software engineer, who is the Chief Technology Officer (CTO) at Google leading the early projects at X. He is known for being one of the lead developers of the Be Operating System (BeOS) and is a noted amateur astro ...

- formerly BFS), it includes support for extended file attributes (

metadata Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including: * Descriptive metadata – the descriptive ...

), with indexing and querying characteristics to provide functionality similar to that of a

relational database A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relati ...

. Whilst intended as a 64-bit-capable file system, the size of some on-disk structures mean that the practical size limit is approximately 2

exabytes The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit ...

. Similarly the extent-based file allocation reduces the maximum practical file size to approximately 260 gigabytes at best and as little as a few blocks in a pathological worst case, depending on the degree of fragmentation. Its design process,

application programming interface An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how ...

, and internal workings are, for the most part, documented in the book ''Practical File System Design with the Be File System''.

Implementations

In addition to the original 1996 BFS used in BeOS, there are several implementations for

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, whi ...

. In early 1999, Makoto Kato developed a Be File System driver for Linux; however, the driver never reached a completely stable state, so in 2001 Will Dyson developed his own version of the Linux BFS driver. In 2002, Axel Dörfler and a few other developers created and released a reimplemented BFS called OpenBFS for

Haiku is a type of short form poetry originally from Japan. Traditional Japanese haiku consist of three phrases that contain a '' kireji'', or "cutting word", 17 '' on'' (phonetic units similar to syllables) in a 5, 7, 5 pattern, and a '' kigo'', or ...

(OpenBeOS back then). In January 2004, Robert Szeleney announced that he had developed a fork of this OpenBFS file system for use in his

SkyOS SkyOS (''Sky Operating System'') is a discontinued prototype commercial, proprietary, graphical desktop operating system written for the x86 computer architecture. As of January 30, 2009 development was halted with no plans to resume its develop ...

operating system. The regular OpenBFS implementation was also ported to

Syllable A syllable is a unit of organization for a sequence of speech sounds typically made up of a syllable nucleus (most often a vowel) with optional initial and final margins (typically, consonants). Syllables are often considered the phonological ...

, with which it has been included since version 0.6.5.

References

External links

The BeOS file system: an OS geek retrospective
by Andrew Hudson, 2010-06-03, Ars Technica {{Haiku Software Disk file systems BeOS Haiku (operating system)

Implementations

See also

References

External links