There is very little mention to the notion of "file server" in the file module documentation while this seems to be currently an important implementation detail and even a requirement in many cases.
An additional intro about "file server" in https://erlang.org/doc/man/file.html would also be a great plus, as it seems to be a big differentiating feature whereas it's not clearly highlighted, only mentioned for a few functions (remote filer server, file server running as slave to the file server of another node, etc.).
I'm creating this issue as discussed in
ERL-1244, since a PR would be welcome by the OTP team