I too use 11 HDD's but mine are set to spin-down after 10 mins. I've brought this issue up a couple times over the years and the only suggestions I received was to always leave the drives spun-up. I don't see this as a solution, rather a workaround and a poor one imo.
You asked that a button to spin-up drives be created. There is one. It's the 'update library on startup' setting in Kodi. Kodi will spin-up each drive one by one and scan them one by one for any changes. Once the process completes, all the drives are spinning and the library is finally ready for navigating. For 11 drives, this process takes 2 or 3 minutes while we twiddle our thumbs and yes it's a painfully slow wait. The time is increased if any new additions were added to any of the drives while waiting for artwork to download and cache.
Considering we might enter the info page about a title and spend 10 or 20 minutes reading actor bios, watching trailers, youtube related video, or simply step away to take a pee, by the time we're done and return to the library to select another title, we can't navigate because the drives have once again spun-down. Many times we watch one title and want to navigate to another. Of course in the time it took to play one title and move on to the next, you guessed it, the drives have spun-down and navigating is impossible until they spin-up again.
One would think the entire purpose of caching to one single drive (C
where the Kodi cache resides, is why we cache in the first place; so the only time a drive needs to spin-up is when it actually needs to be accessed for the title data - not the cached data which is all that is required to navigate.
I (think) the problem is that Kodi itself does not trust the cached data on C: and simply use it solo. I (think) what happens is Kodi wants to double check the cached data on C: against the drive data every single time it's accessed just in case their was some sort of change. I don't think it needs to constantly recheck the cache against the drive simply because it spun-down and needs to spin-up again because a title comes into focus. I think the session should assume nothing has changed after an initial 'update library on start-up'.
I could be waaay off on this thinking but in my mind, cached data is consolidated within the Kodi installation on the C: so it doesn't have to be retrieved from the additional drives otherwise, what's the purpose of having Kodi cache data in the first place? It's meaningless if the drives have to sync with the cached data constantly. The only time a drive(s) should need to spin-up is to access data that isn't cached already. But to require they spin-up just to navigate the library is counterproductive. I understand most folks don't have 11 drives and could care less about any of this. Some folks do though and with the size of UHD rips increasing, it won't be long until multiple drives are common.
Fwiw, I've tried running as vanilla as possible. No artwork or anything else except a poster trying to relax the constant cache update checking. I use the texturecache utility successfully from time to time. None of this helps either. I don't think I'm doing anything improperly but maybe someone has more to add.
