To expand upon that, I had something similar to the OP's setup at one point, and I found things worked a lot better when the files could be moved on the same volume, rather than appearing as separate volumes (because they were mounted separately). I ended up re-engineering my whole setup for that and it's much faster now.
As for duplicates... I assume this is so you can continue seeding after the file has been moved? I can't think of anything that would fit the bill for that off the top of my head. Ideally, I think you'd want QBT to just start serving from the new location instead, though I admit hard links does sound like a solution that could work.
And after Googling, it seems like it already does hard links for torrents for this exact reason. I think if you just map /media (and drop the 2 maps you have after that) things will work like you want.
You can't hard link across docker volumes. In the second example, you need to remove the /media/movies and /media/downloads volumes, only keep /media.
After fixing this, only future downloads will be hard links. Use a deduplication tool like jdupes to create hard links for the already downloaded files.
data
├── torrents
│ ├── movies
│ ├── music
| ├── books
│ └── tv
├── usenet
│ ├── movies
│ ├── music
│ ├── books
│ └── tv
└── media
├── movies
├── music
├── books
└── tv
I couldnt find best way tbh. You could set your qbittorrent to auto delete after some time or when hit specific ratio, then manually delete from arrs. There is also app that auto deletes library after X days (, but didnt try it myself.
None of that suits my needs, so I just do it manually from both qbit and library
Edit: best way is to get more storage so you do it less frequently or you never do it 🙃
I don't think that particular setup has any issue but have you confirmed if it is enabled and they were copies and not hard links? Doing ls -l will show hard link count. Also all of those directories are in home folder right? I don't think you can keep them in different partitions but don't quote me on that.