Be File System

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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 in 1996 over a ten month period to provide BeOS with a modern 64-bit capable journaling file system. 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), it includes support for extended file attributes (metadata) with indexing and querying characteristics to provide functionality similar to that of a relational database.

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. Although the book is now out of print it is freely available as a PDF file [1].

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.

BFS has been reimplemented as OpenBFS as a part of the Haiku open source operating system. SkyFS, a filesystem used in SkyOS, is a fork of OpenBFS.