Store iTunes library on network drive, keep local cache of some media for offline use, and let iTunes organize media on network drive

I have a relatively large iTunes library, a Macbook Pro laptop with a relatively small SSD, and a Linux box with plentiful storage space that is always connected to the internet. I have a dream that one day I will be able to store my iTunes library on the Linux box as a network drive, keep a hand-curated list of songs and podcasts cached on my laptop, and still allow iTunes to organize my media library on the network drive. (Specifically, I want to use the 'Keep iTunes Media folder organized' and 'Copy files to iTunes Media folder when adding to library' options in iTunes so that I can drag-and-drop files into iTunes, have iTunes organize copies via ID3 info, and delete the original files.)

The last time I tried to tackle this problem was ~2 years ago. From what I can recall, my best attempt was a continuously running script that checked if the network drive was accessible and if so, it mounted the network drive where iTunes was set to look for media, and otherwise it moved or mounted (I forget which) a local directory with hand-copied media there instead. I forget exactly why this solution was causing me headaches but obviously it does sound terribly kludgy and I did give up on it. At the time I was trying this, iTunes would not follow symlinks to find media so mounting was necessary.

Lately I've "sucked it up" and stored all my iTunes media on my laptop but right now I'm feeling renewed vigor for solving this problem. Needed clarifications? Thoughts?

I'll try to work on this myself over the next week and update if I think I have new ideas on a good solution.

For this question, I don't want to insist on exactly how iTunes should behave if I attempt to add media while my laptop is offline. Ideally, iTunes would prevent that and display an error message but if that's not feasible and I just need to remember to not do that, it's not a dealbreaker.

Related questions:

Splitting an iTunes Library [duplicate]

iTunes videos on a different harddrive?

A REAL iTunes server on NAS

I don't want to split my iTunes library so this question is a bit different from the ones above. I want the Linux box to have a master copy of all my iTunes media.

Solutions need not be limited to configuration within iTunes. Solutions that "trick" iTunes -- such as how I suggested above by selectively mounting drives to the iTunes media directory -- are fair game. Thanks for reading!

Edit: I promised to update after a week. Currently, I do not have interesting progress to report.

Solution 1:

I'm using Supersync on multiple macs that's based on my qnap nas that keeps track of everything -- from "cloud/not on this machine" "on thismsachine:notonserver" etc.

It also handles dupes, missing tracks, various library issues -- and even better fixes them easily.

I'm not shilling for them -- I have some problems with its quirks -- but with 4 machines, 15 years of iTunes and now a ton of other media that would dwarf my drive it does the trick.

Hope this helps...