While I enjoyed the post, the comparison at the end is unfair. The author compares ZFS with a 475GB NVMe drive as a cache to XFS without an equivalent cache.
The initial comparison with XFS is somewhat unfair as well, though: does XFS provide the same data integrity features that ZFS does? It’s hard, really, to compare file systems with vastly different design centres and feature sets – which feels like the point they’re trying to make, really.
Was the comparison looking at data integrity though? I didn’t see any mention of that anywhere – everything I saw was entirely about performance. If you’re doing a performance comparison of two filesystems, comparing them on (very) different hardware doesn’t seem real meaningful.
The author mentions the possiblity of comparing against something like bcache (which would then be a zfs vs. xfs+bcache comparison rather than strictly a filesystem comparison), but then handwaves it away as “exotic” and concludes, essentially, that “zfs plus additional fancy hardware and a bunch of manual tuning outperforms xfs”. Well…big deal.
At what point do you need to assume integrity as a baseline though? This is a database blog we’re talking here.
Unrelated observation: it’s tragic that most production databases out there aren’t running on ZFS, and says a lot about the priorities (and less charitably the general ability) of our industry.