Disk Standby / Spin Down / Sleep doesn't work, disk being accessed every 30 min · Issue #430 · IceWhaleTech/ZimaOS · GitHub - that’s all I can do.
Feature request: Better power management options (powertop, power governor) - check this topic, or better this one: How to reduce power usage with zima os on generic x86 hardware? - #11 by Casmin7