Disorganized List of Features

• Optimized for high space efficiency (as opposed to speed). It is highly likely that fakefs will be very slow for writes and not particularly fast for reads either. Perhaps ``Astonishingly Slow File System'' would be a better name.

• Interface compatible with POSIX, with the usual Unix features and extensions (users, groups, set-id bits, symlinks, devices, pipes).

• Designed for storing highly redundant collections of files. Capable of performing global searches for common data blocks to reduce the size of the text stored. Can also store completely identical copies of entire files by copy-on-write references.

• Identical copies of a file appear only once in physical storage, but transparently appear as distinct files through the filesystem interface. This is different from normal Unix hard links, which are not distinct.

• Implemented entirely in user-space--ordinary users can create virtual /dev structures, change ownership of files, and act as if they were root within the virtual filesystem, without having root privileges outside of the virtual filesystem. This becomes interesting when combined with...

• ...the optional LD_PRELOAD interface for legacy application support.

• Journaling and concurrent access implemented by Berkeley DB Transactional Data Store.

• Maybe in the future, efficient storage of previous views of the filesystem contents (`snapshots').