Managing filesystem types

The bfs filesystem type

The bfs filesystem type is a special-purpose filesystem. It contains all the stand-alone programs (such as unix) and all the text files necessary for boot procedures. For more information, see ``The stand slice''.

Because the object of the bfs filesystem type is to allow quick and simple booting, bfs was designed as a contiguous flat filesystem. It is not intended to support general users. The only directory bfs supports is the root directory. Users can create only regular files; no directories or special files can be created in the bfs filesystem.

NOTE: The operations that may be performed on a filesystem of type bfs (and, in particular, on the /stand filesystem) are severely limited. For example, it is not possible to have two files open for writing simultaneously, and tasks such as simple compilations will fail if the output file is specified as a bfs file. These restrictions do not apply to operations involving only the reading of files.

A bfs filesystem consists of three parts:

the disk superblock (see ``The bfs superblock'' for details)
the inodes (see ``bfs inodes'' for details)
the storage or data blocks (see ``bfs storage blocks''