There’s been some Friday night kernel drama on the Linux kernel mailing list… Linus Torvalds has expressed regrets for merging the Bcachefs file-system and an ensuing back-and-forth between the file-system maintainer.
Looks dead on arrival to me, so much complexity for “performance” but the filessystem is outclassed by everything else in existence. If there was any real performance from this complexity it could have cool niche use cases but this is very disappointing https://www.phoronix.com/review/bcachefs-linux-67/2
Brand new anything will not show up with amazing performance, because the primary focus is correctness and features secondary.
Premature optimisation could kill a project’s maintainability; wait a few years. Even then, despite Ken’s optimism I’m not certain we’ll see performance beating a good non-cow filesystem; XFS and EXT4 have been eeking out performance for many years.
Cow is an excuse for writing performance, though the read is awful too currently
A rather overly simplistic view of filesystem design.
More complex data structures are harder to optimise for pretty much all operations, but I’d suggest the overwhelmingly most important metric for performance is development time.
It has gotten better since November of last year though, here’s a more recent benchmark showing it beating btrfs quite often: https://www.phoronix.com/review/linux-611-filesystems/2