Btrfs is a new filesystem that is designed to be scalable, efficient and fast. Notable features include very fast offline filesystem check, online filesystem checking, checksumming of all metadata and fast, writable filesystem snapshots. . This package provides the source code for the btrfs kernel modules. . WARNING: 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.