Caching on local disk

[Z3thor 0]

I have installed emby on my CLEAR LINUX SERVER OS system. Here I have attached cca 20 HDDs (via SATA) mounted into dir /_discs/001, /_discs/002, etc. These HDDs are set to go into spindown after 10mins of no activity. I have added movies to the library from all of these discs using the option "Keep a cached copy of images in the server's metadata folder" enabled (please see attached images). All libraries has even been rescanned (used the "refresh metadata" to force recache all images, etc.). I would expect that all thumbnails and other infos are being saved into the cache folder in the system drive. But obviously they arent. When I go to the Movies library, all the thumbnails are reloading everytime I get in (at first I see placeholders only, then I hear the HDDs spinning up, then the images starts to appear, like when they are loaded from the HDDs instead from the cache) and therefore waking up all the harddrive during only viewing the movie list (even when I dont go to any movie detail). Why is that? I would expect that the HDD with the selected movie would be waked up after opening the movie detail (or playing it). But now all the HDDs are spinning on even during browsing the movie library. Why? Why it has to wake up the HDDs? Does it mean that not all data are cached? How to achieve it then pls?

Edited July 18, 2025 by Z3thor

[Luke 42077]

@Z3thorHi, do you have theme songs? Could that be why they are spinning up?