Btrfss

Btrfs, which stands for B-tree file system, is a modern copy-on-write (CoW) file system for Linux. It was designed with features aimed at fault tolerance, ease of administration, and self-healing. Key features of Btrfs include snapshots, which allow for point-in-time copies of the file system, and data integrity checks through checksumming. It also supports subvolumes, which can be mounted and unmounted independently and behave like separate file systems for certain operations.

Btrfs offers integrated volume management, meaning it can span multiple devices and manage them as a single storage pool. This allows for features like RAID configurations, including RAID 0, RAID 1, RAID 10, and RAID 5/6 (though RAID 5/6 are still considered less stable than other RAID levels). Data and metadata are checksummed separately, and Btrfs can detect and often automatically correct silent data corruption if multiple copies of the data exist.

The copy-on-write nature means that when data is modified, Btrfs writes the new data to a new location rather than overwriting the old data in place. This is fundamental to its snapshotting capabilities and helps prevent data corruption during unexpected shutdowns. While Btrfs has become increasingly stable and is used in production environments by various Linux distributions, some advanced features, particularly certain RAID configurations, may still be considered experimental by some users.