ZFS-GPL

An independent, clean-room reimplementation of the ZFS filesystem in Rust, licensed GPL-2.0-or-later. It reads and writes the same on-disk format as OpenZFS, so the two can sit on one machine.

OpenZFS is CDDL, which is incompatible with GPLv2 and is the reason ZFS has never shipped in the mainline Linux tree. This project shares no code with OpenZFS. It is built from the published on-disk format and from behavioural observation, and development runs as a formal clean room: a spec side may study OpenZFS and writes fact-only functional specifications, while the implementation side works only from approved specifications and never sees the source. The two run on isolated systems, and the single crossing point is a gatekept, commit-pinned specification repository whose history is permanent.

It also sheds the original Solaris design constraints - the shim layer, a device discovery process that makes little sense on Linux, and caching tied to the filesystem module - and is cross-platform by design.

Pre-alpha: the tree currently holds the design and the clean-room process that governs how the code may be written.

Highlights

• On-disk compatible with OpenZFS in both directions, tracking one prior stable minor release or three months, whichever is longer.
• Coexists with an installed OpenZFS: distinct binary and module names, and no shared device paths or state files.
• Uses the native OS page cache instead of a reimplemented ARC.
• Device discovery by native enumeration and label scan, not a cache file.
• Cross-platform by design: Linux, BSD, Solaris, and Windows.