Be File System
From Wikipedia, the free encyclopedia
| BFS | |
|---|---|
| Developer | Be Incorporated |
| Full name | Be File System |
| Introduced | (BeOS R3) |
| Partition identifier | Be_BFS (Apple Partition Map) 0xEB (MBR) |
| Structures | |
| Directory contents | B+ tree |
| File allocation | Inodes |
| Bad blocks | Inodes |
| Limits | |
| Max file size | ~260 GB * |
| Max number of files | Unlimited |
| Max filename size | 255 characters |
| Max volume size | ~2 EB * |
| Allowed characters in filenames | All UTF-8 but "/" |
| Features | |
| Dates recorded | Access, Creation, Modified |
| Date range | Unknown |
| Forks | Yes |
| Attributes | POSIX ACLs: Read, Write, Execute |
| File system permissions | Yes, POSIX (RWX per owner, group and all) |
| Transparent compression | No |
| Transparent encryption | No |
| Supported operating systems | BeOS, ZETA |
The Be File System (BFS, occasionally misnamed as BeFS) is the native file system for the BeOS operating system.
BFS was developed by Dominic Giampaolo and Cyril Meurillon over a ten month period, starting in September 1996[1], to provide BeOS with a modern 64-bit capable journaling file system[2]. It is case sensitive and capable of being used on floppy, hard disks and read-only media such as CD-ROMs, although its use on small removable media is not advised, as the file system headers consume from 600KB to 2MB, rendering floppy disks virtually useless.
Like its predecessor, OFS (written by Benoit Schillings, Old Be File System, was also called BFS when current[3]), 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.
Contents |
[edit] Implementations
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[4].
As part of the OpenBeOS attempt to recreate the BeOS operating system, in 2002 Axel Dörfler and a few other developers created and released a reimplemented BFS called OpenBFS[5]. In January 2004, Robert Szeleney announced that he had developed a fork of this OpenBFS filesystem for use in his SkyOS operating system[6].
[edit] References
- ^ Giampaolo, Dominic (1999). Practical File System Design with the Be File System. Morgan Kaufmann. ISBN 1-55860-497-9.
- ^ Andrew Orlowski (March 29, 2002). Windows on a database – sliced and diced by BeOS vets. The Register. Retrieved on 2006-12-09.
- ^ Henry Bortman. Benoît Schillings, Software Engineer. The BeOS Bible. Retrieved on 2006-09-10.
- ^ Will Dyson (2002). BeFS driver for Linux: About BeFS. SourceForge. Retrieved on 2006-12-09.
- ^ Daniel Teixeira (September 04, 2002). OBFS Reaches Beta. Haiku News. Retrieved on 2006-12-09.
- ^ Robert Szeleney (January 23, 2004). Update. skyos.org. Retrieved on 2006-12-09.
