btrfs-nodatasum · shipping · also NODATASUM, Btrfs no-data-checksum flag

Btrfs NODATASUM

Btrfs NODATASUM marks file data as excluded from the filesystem's data checksumming.

Related Observatory article: Btrfs NODATASUM on hesela.com

NODATACOW implies NODATASUM, but disabling data checksums is not synonymous with disabling copy-on-write; the mount option applies to newly created files. Metadata remains checksummed.

Relations

related

data-scrubbing, checksum, copy-on-write, mirroring

Limitations

• Scrub cannot checksum-validate the affected file data or use those missing checksums to select a correct mirror after silent damage. [2]

Citations

1. Btrfs documentation: btrfs(5), datacow/nodatacow and datasum/nodatasum (accessed 2026-10-13)
2. Btrfs documentation: btrfs-scrub(8), checksum exclusions and read-only limitations (accessed 2026-10-13)
3. Btrfs documentation: Deduplication, compatibility of COW files with NODATASUM (accessed 2026-10-13)
4. Hesela: Disk scrubbing, checksum coverage and consistency boundaries (accessed 2026-10-13)

JSON: /data/terms/btrfs-nodatasum.json