WinBtrfs is a Windows driver that enables the Btrfs filesystem to be read and written on Windows systems.
The tool solves the problem of accessing Btrfs filesystems from Windows by implementing a complete driver from scratch without using Linux kernel code. This approach allows it to work across Windows versions from XP onwards and be included in ReactOS. The driver handles the full range of Btrfs features including RAID levels 0, 1, 10, 5, and 6, compression formats, snapshots, subvolumes, and advanced operations like balancing and scrubbing. It bridges Linux and Windows by mapping Linux users to Windows accounts and storing Linux extended attributes as Windows Alternate Data Streams and ACLs.
Developers should choose this tool if they need to access Btrfs filesystems from Windows for data interchange, backup, or development purposes. It suits scenarios where Btrfs volumes are created on Linux systems and must be accessed from Windows machines, or where cross-platform filesystem compatibility is required. The README notes companion tools for related tasks: WinMD for handling Linux MD software RAID devices, Quibble as an experimental bootloader for Windows on Btrfs, and Ntfs2btrfs for converting NTFS filesystems to Btrfs in place.
Development activity shows consistent maintenance with regular feature additions tracking upstream Btrfs development, including support for newer checksum types, compression algorithms, and filesystem structures. The project includes a substantial todo list covering remaining features like fs-verity support, zoned storage, defragmentation, and quota support, indicating ongoing work toward fuller Btrfs compatibility. The codebase is actively refined with bug fixes and optimizations across core driver functionality.
