I read through these and also tried searching your fora. What is unclear to me is how exactly the command works. 
I'm using this: ipfs add --raw-leaves --nocopy --recursive --hidden --fscache --progress $dir
1.) I was under the impression that '--fscache' skips files already added once, however it still prints them out the same way as if adding them the first time.
2.) I have 4 10TB HDD in a Lx software raid as one partition. I'm trying to add a folder with 23TB and 15+ million files. Is there any way to actually speed this up because right now it's doing between 1 and 5 files a second depending o their size.
3.) Can the hashes be calculated on another machine (say, with an SSD for speed. _IF_ the storage medium even matters) and then imported to my other machine so I do not have to generate them there?
Right now it would take me over 2 months to add everything. And a additional problem is that the contents change frequently so I'd have to rerun the add command again.
Splitting the add command onto subfolders isn't an option since it wouldn't give me one has with everything in it (as far as I know). Unless there is a way to combine them later.