UPS & Power Daemon // VERSION: v2.8.2 Stable // LICENSE: GPLv2+
● 100% LOCAL LAN EXECUTION (18 MB Daemon • <32 MB RAM)
Network UPS Tools (NUT) & APCUPSD Daemon
Protocols: SNMPv3 • USB-HID • Graceful Shutdown • UK Regulatory Clearance: 100% cleared for UK commercial server rooms; vendor-neutral USB-HID and SNMPv3 polling with zero cloud telemetry.
Architectural Overview
Industry-standard Linux/BSD daemon that monitors APC Smart-UPS Li-Ion and Eaton 9PX rack UPS units over USB or SNMP, orchestrating staged graceful shutdowns of hypervisors and Synology WORM NAS arrays before batteries deplete.
72-Hour Blackout Plant-Room Use Case
Prevents catastrophic Btrfs/ZFS RAID corruption and VMware/Proxmox filesystem damage when an unattended weekend blackout outlasts rack UPS battery runtime.
Production Configuration & Deployment Snippet
# /etc/nut/upsmon.conf — Staged Commercial Rack Shutdown MONITOR [email protected] 1 monuser secretPass master MINSUPPLIES 1 SHUTDOWNCMD "/sbin/shutdown -h +0 'NUT: Commercial UPS Low Battery (20% SoC)'" NOTIFYFLAG ONBATT SYSLOG+WALL+EXEC NOTIFYFLAG LOWBATT SYSLOG+WALL+EXEC