@zwol I didn't think that's true. I've understood that all data on-disk has a checksum- data and metadata/structure alike. If (meta)data is damaged on-disk, the way of repairing it is to copy it from a redundant copy, not fill in the blanks with zeroes and guesses like fsck or hardware raid might do. Using zfs without mirroring or raidz is a recipe for disaster, and that should be made more clear. But storing important data without a redundancy scheme at all is a recipe for disaster.