The catch is that scrubs are expensive, especially when the pool holds petabytes. An admin who hit a power-supply problem or a sudden shutdown usually wants to scrub the data written around that event, not the entire pool. That is the goal here: teach ZFS something about wall-clock time.

Internally, ZFS only thinks in transaction group (TXG) numbers. Administrators, inconveniently, think in dates. A TXG is just a uint64_t that goes up with every transaction, and there has never been a clean way to map between the two. //

With the database in place, zpool scrub learned two new flags: -S for the start date and -E for the end date. Both accept "YYYY-MM-DD" or "YYYY-MM-DD HH:MM" in local time. The end date is rounded up: scrubbing a bit more than asked is fine, scrubbing less is not.

shipped in OpenZFS 2.4.0.