https://www.abclinuxu.cz/poradna/hardware/show/244460
smartctl
https://www.truenas.com/community/threads/ataidle-vs-smartctl-for-spindown.23393/
After playing around with Freenas, I've come to the conclusion that I would like to spindown in evening only i.e. when people are also asleep. So I thought...
vssmartctlspindowntruenascommunity