> One thing to note is that checks and resyncs of the proposed setup are significantly prolonged (by a factor of 3 to 4) compared to an mdraid without the integ

> One thing to note is that checks and resyncs of the proposed setup are significantly prolonged (by a factor of 3 to 4) compared to an mdraid without the integrity-layer underneath. The investigation so far has so far not revealed the underlying cause. It is not CPU-bound, indicating that the read-performance is not held back by checksumming, the latency figures above do not imply an increase in latency significant enough to cause a factor 3-4 prolonged check-time, disabling the journal did not change this either (as one would expect, as the journal is unrelated to read, which should be the only relevant mode for a raid-check). > ZFS was roughly on par with mdraid without the integrity-layer underneath with regard to raid-check time. > If anyone has an idea of the root cause of this behavior, feel encouraged to contact me, I’d be intrigued to know. note that by default ZFS is tuned to prioritize online transactions at the expense of scrub/resilver speed, as this is a sensible choice for its intended use-case of business storage appliances. Businesses can't stop the world for a resilver. For your average home NAS, you can tune ZFS to scrub/resilver faster, not really a big deal as you are not really hammering it anyway. https://www.reddit.com/r/zfs/comments/6t799g/really_slow_scrub/ https://www.reddit.com/r/zfs/comments/6t799g/really_slow_scr... https://www.ixsystems.com/community/threads/scrub-performance-tuning.51959/ https://www.ixsystems.com/community/threads/scrub-performanc...