> I dropped btrfs after the second time it hosed my rootfs

btrfs fans use the "you're using it wrong" excuse a lot.

I recall a failure mode that activated when you fill the FS to 100% and their response was "you should never fill a filesystem to capacity"

That failure mode is still there although it's been mitigated a bit. I hit it a few months ago but was able to recover after a few hours of doing various stuff.

It's really a shame, though. btrfs is permanently unfinished, and zfs has the wrong license. End result is people stick with ext4 or xfs most of the time anyway.

Otoh, good luck bringing a CoW filesystem back from 100%. Delete a file? Sure, let me just make a copy of all the metadata that was pointing at it using... the zero blocks I have left.

Tradeoffs are a bitch, bitch.