Announcing XRAID: declustered parity RAID for zoned XFS

Christoph Hellwig has announced the initial public release of XRAID, a declustered parity RAID system integrated into XFS. The key objectives of XRAID are to support parity RAID on zoned devices, such as SMR hard drives, and to provide a high-performance RAID implementation without data integrity issues. XRAID is compatible with conventional hard drives and SSDs as well.

The system's performance optimization has not been a priority, but it still shows a significant performance boost, with write speeds up to 20 times faster than mdraid.

Development on XRAID has been ongoing for a year and a half, and while it is not yet ready for upstream submission, Hellwig is eager to gather feedback and test the system with a broader audience. The current version supports parity levels ranging from zero to two. Although experiments with the SnapRAID parity library were conducted to enable support for three or more parities, this feature is not included in the present version but is planned for future updates.

The xfsprogs branch of the codebase includes mkfs support and a new xraid utility for managing devices and inspecting XRAID file systems. Additionally, Zonar, a tool for visualizing zoned file systems, has been extended to illustrate how logical zones map to physical zones on devices. Hellwig presented XRAID at the FOSSY conference in August, but a video of his talk is not available. Nevertheless, his slides are accessible for further information.