The (unstable and development-oriented only) filesystem Btrfs version 0.14 has been released. “Btrfs is a new copy on write filesystem for Linux aimed at implementing advanced features while focusing on fault tolerance, repair and easy administration. Initially developed by Oracle, Btrfs is licensed under the GPL and open for contribution from anyone.”Besides the obvious bug and performance fixes, the email announcement lists the main new feature of this release:

The major new feature is the ability to manage multiple devices under a single Btrfs mount. Raid0, raid1 and raid10 are supported. Even for single device filesystems, metadata is now duplicated by default. Checksums are verified after reads finish and duplicate copies are used if the checksums don’t match.

The stable release can be downloaded from here, and the source repositories are here. Don’t miss the big warning, though: “Btrfs is under heavy development, and is not suitable for any uses other than benchmarking and review. The Btrfs disk format is not yet finalized.”