12x 3.5" HDDs spinning up simultaneously can spike ~240W, pushing a single 750W PSU close to its limit. Two-layer fix: - Layer 1: racadm iDRAC BIOS setting (HddSeq) fires at POST before OS loads - Layer 2: stagger-spinup.service wakes drives one at a time via hdparm on boot https://claude.ai/code/session_01TxTSnxDjgEVuNztdsWQjMD