They are not, but they are better at swallowing the errors and not bothering you with such details. ZFS fails fast & early, while EXT4 will fail when you realiz

They are not, but they are better at swallowing the errors and not bothering you with such details. ZFS fails fast & early, while EXT4 will fail when you realize your Postgres DB is borked. I guess it's possible that some type of disk command timing could cause unexpected lockups or slowdowns that you wouldn't get with a system that doesn't try to control the hardware to quite the same extent as ZFS, but my (cursory) understanding is that it's rare/hardware specific. My personal take is that running ZFS on hardware that lies is no worse than running EXT4 on it. YMMV as I'm not a storage expert.