Yeah, I certainly understand ZFS was designed for different types of storage, but we now have flash storage as a default ... Which is why I do these benchmarks

Yeah, I certainly understand ZFS was designed for different types of storage, but we now have flash storage as a default ... Which is why I do these benchmarks - to educate myself and learn what behavior to expect from different systems, and maybe even find stuff to optimize in Postgres. The goal definitely is not to "shame" some of the filesystems (or whatever I benchmark), I have huge respect to all of the engineers working on these things. FWIW I really like the ideas behind ZFS, and many deployments chose to use it. But that's kinda the point - to decide what's the right trade off you need to have some basic understanding what kind of behavior to expect.