"The Meta infrastructure is built completely on btrfs and its features. We have saved billions of dollars in infrastructure costs with the features and robustness of btrfs."
So this ZFS data corruption issue caused me being insecure about my data safety and to check my system for bit rot with btrfs scrubbing…
Scrub is a pass over all filesystem data and metadata and verifying the checksums. Basically, it reads all data on the disk, recomputes its checksum, and compares the recomputed checksum to the stored one. When the stored and recomputed checksums don’t match, the system knows there’s corruption.
Btrfs scrub is a filesystem checking tool that reads all the data and metadata on the filesystem and uses checksums and the duplicate copies from RAID storage to identify and repair any corrupt data
To start a BTRFS scrub and to check the status of this process:
/root 