I have been using an old PC as NAS and running docker containers (Immich, Nextcloud, paperless-ngx etc.). I got 5 3.5" HDD disks and a Nvme. Even on idle, I am consuming 50-60w. A friend of mine is selling a Qnap NAS which is a dedicated machine and probably consumes less power, although I don’t know if it’s worth it.
if it’s for drive health stats, and the device runs linux, hd-idle could help. it only counts actual block device (so, storage) access as activity
edit: https://github.com/adelolmo/hd-idle
They run a custom vendor-locked distro named QTS, so they’re not really as easy to modify as a normal system, I don’t think you can even install programs like that.
I’ll definitely bookmark it though if I ever get around to building my own solution, thanks!