Do people really use copy-on-write filesystems though? I mean it'd be great if that were a default, but I rarely encounter them, and when I do, it's only because someone intentionally set it up that way. In 30+ years of using Unix systems, I can't even definitively recall one of them having a copy-on-write filesystem in place. Which is insane considering I used VAX/VMS systems before that and it was standard there.