A 1994 book called 'The Design and Implementation of a Log-structured file system' contains the claim "We have implemented a prototype log-structured file system called Sprite LFS; it outperforms current Unix file systems by an order of magnitude for small-file writes while matching or exceeding Unix performance for reads and large writes." That would seem on the face of it to constitute a compelling case to start using the file system in question, which raises the question of why this did not happen.
The Unix Haters Handbook claims this is because Sprite LFS not only was not compatible with the Unix API, but could not be; that user-visible aspects of the Unix API preclude high performance in any file system that retains compatibility. Granted that this book disclaims impartiality by its very title, I'm still interested in whether they are right.
Did the classic Unix API indeed preclude high-performance file systems like Sprite LFS? If so, what features of the API were responsible for this? (And how was the problem eventually resolved? I haven't seen anyone claim modern Linux file systems lack performance, and I'm under the impression Linux retains a high degree of backward compatibility.)