Be File System
Encyclopedia
The Be File System is the native file system
for the BeOS
.
BFS was developed by Dominic Giampaolo
and Cyril Meurillon over a ten month period, starting in September 1996, to provide BeOS
with a modern 64-bit
capable journaling file system
. It is case sensitive and capable of being used on floppy
, hard disk
s and read-only media such as CD-ROM
s, although 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
, was also called BFS when current), it includes support for extended file attributes (metadata) with indexing and querying characteristics to provide functionality similar to that of a relational database
.
Whilst intended as a 64-bit capable file system, the size of some on-disk structures mean that practical size limit is approximately 2 exabytes. 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
, and internal workings are, for the most part, documented in the book Practical File System Design with the Be File System.
, there are several implementations for Linux
. In early 1999, Makoto Kato developed a Be File System driver for Linux; however, the driver never reached a complete stable state, so in 2001 Will Dyson developed his own version of the Linux BFS driver.
As part of the OpenBeOS attempt (now Haiku
) to recreate the BeOS operating system, in 2002 Axel Dörfler and a few other developers created and released a reimplemented BFS called OpenBFS. In January 2004, Robert Szeleney announced that he had developed a fork of this OpenBFS file system for use in his SkyOS
operating system. The regular OpenBFS implementation was also ported to Syllable
and is included since version 0.6.5.
File system
A file system is a means to organize data expected to be retained after a program terminates by providing procedures to store, retrieve and update data, as well as manage the available space on the device which contain it. A file system organizes data in an efficient manner and is tuned to the...
for the BeOS
BeOS
BeOS is an operating system for personal computers which began development by Be Inc. in 1991. It was first written to run on BeBox hardware. BeOS was optimized for digital media work and was written to take advantage of modern hardware facilities such as symmetric multiprocessing by utilizing...
.
BFS was developed by Dominic Giampaolo
Dominic Giampaolo
Dominic B. Giampaolo is a software developer who helped develop the Be File System for the Be Operating System and currently works at Apple Inc....
and Cyril Meurillon over a ten month period, starting in September 1996, to provide BeOS
BeOS
BeOS is an operating system for personal computers which began development by Be Inc. in 1991. It was first written to run on BeBox hardware. BeOS was optimized for digital media work and was written to take advantage of modern hardware facilities such as symmetric multiprocessing by utilizing...
with a modern 64-bit
64-bit
64-bit is a word size that defines certain classes of computer architecture, buses, memory and CPUs, and by extension the software that runs on them. 64-bit CPUs have existed in supercomputers since the 1970s and in RISC-based workstations and servers since the early 1990s...
capable journaling file system
Journaling file system
A journaling file system is a file system that keeps track of the changes that will be made in a journal before committing them to the main file system...
. It is case sensitive and capable of being used on floppy
Floppy
Floppy may refer to:* Floppy disk or floppy disk drive* Floppy disk controller* The Floppy Show* Mr. Floppy from the Sitcom Unhappily Ever After* Mr Floppy Australian rock band* Floppy a character from The Magic Key...
, hard disk
Hard disk
A hard disk drive is a non-volatile, random access digital magnetic data storage device. It features rotating rigid platters on a motor-driven spindle within a protective enclosure. Data is magnetically read from and written to the platter by read/write heads that float on a film of air above the...
s and read-only media such as CD-ROM
CD-ROM
A CD-ROM is a pre-pressed compact disc that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed by Sony and Philips adapted the format to hold any form of binary data....
s, although 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
Benoit Schillings is a Belgian software engineer, who until recently was the chief technology officer at Myriad Group,. He is known for being one of the lead developers of the Be Operating System and is a noted amateur astronomer....
, was also called BFS when current), it includes support for extended file attributes (metadata) with indexing and querying characteristics to provide functionality similar to that of a relational database
Relational database
A relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
.
Whilst intended as a 64-bit capable file system, the size of some on-disk structures mean that practical size limit is approximately 2 exabytes. 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
File system fragmentation
In computing, file system fragmentation, sometimes called file system aging, is the inability of a file system to lay out related data sequentially , an inherent phenomenon in storage-backed file systems that allow in-place modification of their contents. It is a special case of data fragmentation...
.
Its design process, application programming interface
Application programming interface
An application programming interface is a source code based specification intended to be used as an interface by software components to communicate with each other...
, 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 BeOSBeOS
BeOS is an operating system for personal computers which began development by Be Inc. in 1991. It was first written to run on BeBox hardware. BeOS was optimized for digital media work and was written to take advantage of modern hardware facilities such as symmetric multiprocessing by utilizing...
, there are several implementations for Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
. In early 1999, Makoto Kato developed a Be File System driver for Linux; however, the driver never reached a complete stable state, so in 2001 Will Dyson developed his own version of the Linux BFS driver.
As part of the OpenBeOS attempt (now Haiku
Haiku (operating system)
Haiku is a free and open source operating system compatible with BeOS. Its development began in 2001, and the operating system became self-hosting in 2008, with the first alpha release in September 2009, the second in May 2010 and the third in June 2011....
) to recreate the BeOS operating system, in 2002 Axel Dörfler and a few other developers created and released a reimplemented BFS called OpenBFS. In January 2004, Robert Szeleney announced that he had developed a fork of this OpenBFS file system for use in his SkyOS
SkyOS
SkyOS was a prototype commercial, proprietary, graphical desktop operating system written for the x86 computer architecture. As of January 30, 2009 development has halted and no plans to resume its development have been announced.- History :...
operating system. The regular OpenBFS implementation was also ported to Syllable
Syllable (operating system)
Syllable Desktop is a free and open source operating system for Pentium and compatible processors. Its purpose is to create an easy-to-use desktop operating system for the home and small office user...
and is included since version 0.6.5.