Why metrics

Logs tell you what happened; metrics tell you how things are trending. Is the host running out of memory? Is disk filling up? Is CPU pegged? Those are numbers over time, and you want them charted and alertable, not discovered by accident.

The lab runs a metrics stack on the Monitoring VM (10.100.100.4): InfluxDB as the time-series database and Grafana as the dashboards on top. The first thing it watches is the foundation everything else stands on — the Proxmox host itself.

Why we use this: you can't manage what you can't see. A host quietly creeping toward full RAM or disk is the kind of thing that's obvious on a graph weeks in advance and catastrophic when discovered at failure time. Metrics turn slow-moving problems into things you notice early.