context: I am running a small self made NAS with Ubuntu as OS, with a small ssd for OS and hdds for (user-)data. Since for now just some few people are accessing files on the NAS I used to spin down the hdds after some idle time to lower energy consumption. Disks are being spun-up if someone needs access to some data on the hdds. Works like a charm. Recently I found an interesting solution were the NAS can be suspended to RAM but will get wake-up calls from the router via magic packets when the router detects incoming requests on the ports forwarded to the NAS. This allows me to have a very low energy consumption but still be able to run the services I want to.
problem description: I just learned that because I have a webserver running, several spiders (e.g. baidu) are regularly (several times a day) scanning for some files. This will result in my NAS resuming from suspend and serving those requests. Unfortunately none of those requests do need any kind of access to the data disks but because system was suspended and is waking up, the disks will spin up. The requests itself from baidu or others don't bother me but if my NAS is requested several times a day, I will soon have a very high spin-up count on my hdds which are not involved with serving the requests anyhow. Just the sdd is involved and therefore should be activated. Even if it not was on baidu, other requests are imaginable where the hdds with the data are not involved.
question: Is there a possibility to wake a computer from a suspended state (to RAM/Disk or whatever) without spinning up all hard drives and how does it work?
subsequent question: If YES, is it possible to have a list of hard drives which are spun-up or kept in suspend when waking up?
comprehension question: I would guess what I asked is not possible because it is related to the hardware/bios which has to reconnect/check all the devices contained in the system for some reason. If this is not correct why can't the OS which knows its hardware components before being suspended let the devices stay in suspended state until they are really needed.
Thanks for reading my question. I hope someone can give me some clues on this since I was not able to find anything related in hours of googling. Lets hope I not just used the wrong terms :)