Can anyone tell me what it is that Roon is doing when it rattles my NAS drives 24/7?

Can anyone tell me what it is that Roon is doing when it rattles my NAS drives 24/7? I add music rarely and it may be a few albums at a time. The last album I added was the new Taylor Swift album when it came out yet the NAS is still getting rattled constantly. What is Roon doing and how do we stop this behaviour?

Last night I got so fed up I just killed the Roon services in my Mac Mini.

I may need to move my data off the NAS if this issue can’t be solved. It wasn’t always like this, what’s happened?