btrfs · shipping · also B-tree filesystem

Btrfs

Btrfs is a Linux filesystem built around copy-on-write B-trees, with integrated snapshots, checksumming and multi-device storage.

Copy-on-write does not remove the need for recovery: Btrfs uses a separate tree log for eligible fsync updates before a full transaction commit. Checksum coverage and mount-time recovery depend on the features and options in use. [1] [2] The subvolume ro property is separate from read-only mounting. [5]

Relations

related

copy-on-write, snapshot, btrfs-nodatasum, btrfs-tree-log, checksum, btrfs-read-only-subvolume

Limitations

• File data marked NODATASUM is outside data-checksum coverage; copy-on-write is not itself an application transaction or independent backup. [3]

Citations

1. Josef Bacik (2012). Btrfs: The Swiss Army Knife of Storage. USENIX ;login:, volume 37, number 1, Filesystem Consistency section. (accessed 2026-10-15)
2. Linux v6.16: Btrfs tree-log.c, design comment and replay implementation (accessed 2026-10-15)
3. Btrfs documentation: btrfs(5), tree logging and rescue mount options (accessed 2026-10-15)
4. Hesela: Btrfs tree logs, read-only replay and version boundaries (accessed 2026-10-15)
5. Btrfs documentation: subvolume flags and non-recursive snapshots (accessed 2026-10-15)

JSON: /data/terms/btrfs.json