Workloads spread one-per-server or across many lightly loaded hosts keep every host powered and cooled. Over time placements drift and utilisation falls further.
The fix you can use today
Find hosts that are consistently underloaded.
Migrate their workloads onto fewer hosts, leaving headroom for peaks.
Power down or repurpose the emptied hosts, and repeat periodically.
One study found that packing virtual machines onto fewer servers can cut energy by up to 22%. GreenCode's research review draws on this work.
Tools that help
Kepler: exports energy estimates per pod and container on Kubernetes, using eBPF and hardware counters
Scaphandre: measures the power drawn by each process on a Linux server and exports it to Prometheus and other monitoring stacks
ipmitool: reads a server's power from its management controller (`ipmitool dcmi power reading`)
How GreenCode helps
GreenCode helps tackle this by mining a running estate and rebuilding it as infrastructure as code. It traces energy and CO2e to the services that cause it, including the ones barely running at all. More on this.
