Documentation: add performance overhead estimates

[ngirard]

Documentation: add performance overhead estimates

[sloonz]

Hello,

I am sorry, but I have no plan to do that. Filesystems benchmarking is a hard and contentious topic ; if you think that performances may be problematic for your use-case, I suggest you to run tests with the specific workload you have in mind.

From my quick, non-rigorous tests : FUSE has an important, non-negligible overhead (you can check this by yourself by testing the passthrough FUSE example ; running tar on my home folder is 5x slower, if my memory serves me right). rewritefs has a pretty-much non-existent overhead relatively to FUSE, but obviously suffers from the overhead of FUSE himself

Cheers

[ngirard]

@sloonz, thanks for your answer.

FUSE has an important, non-negligible overhead (you can check this by yourself by testing the passthrough FUSE example ; running tar on my home folder is 5x slower, if my memory serves me right). rewritefs has a pretty-much non-existent overhead relatively to FUSE, but obviously suffers from the overhead of FUSE himself

Actually, simply adding this piece of information to the README would already help a lot, IMHO.