Be File System
| Developer(s) | Be Inc. |
|---|---|
| Full name | Be File System |
| Introduced | May 10, 1997; 28 years ago (1997年05月10日) with BeOS Advanced Access Preview Release[1] |
| Partition IDs | Be_BFS (Apple) 0xEB (MBR) 42465331-3BA3-10F1-802A-4861696B7521 (GPT) |
| Structures | |
| Directory contents | B+ tree [2] |
| File allocation | inodes |
| Bad blocks | inodes |
| Limits | |
| Max volume size | ~2 EB * |
| Max file size | ~260 GB * |
| Max no. of files | Unlimited |
| Max filename length | 255 characters |
| Allowed filename characters | All UTF-8 but "/" |
| Features | |
| Dates recorded | Access, Creation, Modified |
| Date range | Unknown |
| Date resolution | 1s |
| Forks | Yes |
| File system permissions | Unix permissions, POSIX ACLs |
| Transparent compression | No |
| Transparent encryption | No |
| Other | |
| Supported operating systems | BeOS, ZETA, Haiku, SkyOS, Syllable, Linux |
The Be File System (BFS) is the native file system for the BeOS. In the Linux kernel, it is referred to as "BeFS" to avoid confusion with Boot File System.
BFS was developed by Dominic Giampaolo and Cyril Meurillon over a ten-month period, starting in September 1996,[2] to provide BeOS with a modern 64-bit-capable journaling file system.[3] It is case-sensitive and capable of being used on floppy disks, hard disks and read-only media such as CD-ROMs. 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 - formerly BFS),[4] 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 the 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.[citation needed ]
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.[2]
Implementations
[edit ]In addition to the original 1996 BFS used in BeOS, 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 completely stable state, so in 2001 Will Dyson developed his own version of the Linux BFS driver.[5]
In 2002, Axel Dörfler and a few other developers created and released a reimplemented BFS called OpenBFS for Haiku (OpenBeOS back then).[6] In January 2004, Robert Szeleney announced that he had developed a fork of this OpenBFS file system for use in his SkyOS operating system.[7] The regular OpenBFS implementation was also ported to Syllable, with which it has been included since version 0.6.5.
See also
[edit ]References
[edit ]- ^ Scot Hacker (1997年07月01日). "BeOS Journal 10: A First Look at DR9". ZDNet. Archived from the original on 1999年10月02日. Retrieved 2007年03月22日.
- ^ a b c Giampaolo, Dominic (1999). Practical File System Design with the Be File System (PDF). Morgan Kaufmann. ISBN 1-55860-497-9. Archived from the original (PDF) on 2017年02月13日. Retrieved 2004年06月01日.
- ^ Andrew Orlowski (2002年03月29日). "Windows on a database – sliced and diced by BeOS vets". The Register. Archived from the original on 30 December 2006. Retrieved 2006年12月09日.
- ^ Henry Bortman. "Benoît Schillings, Software Engineer". The BeOS Bible. Archived from the original on 27 September 2006. Retrieved 2006年09月10日.
- ^ Will Dyson (2002). "BeFS driver for Linux: About BeFS". SourceForge. Retrieved 2006年12月09日.
- ^ Daniel Teixeira (2002年09月04日). "OBFS Reaches Beta". Haiku News. Archived from the original on 2006年10月04日. Retrieved 2006年12月09日.
- ^ Robert Szeleney (2004年01月23日). "Update". skyos.org. Archived from the original on 2007年09月26日. Retrieved 2006年12月09日.
External links
[edit ]- The BeOS file system: an OS geek retrospective, by Andrew Hudson, 2010年06月03日, Ars Technica