Notes on Optimising Energy Usage

I live in a very sun-rich place. And we have solar panels on our roof that generate around 34 KWh’s during the summer daylight hours, less in winter. This largely covers our use during the day, notwithstanding a scenario where we have the Dishwasher, Washing Machine and Dryer all on at once (and the Homelab of course!) which happends from time to time. Ever since having the panels installed, I have been more energy conscious, partly because we now have visibility of our usage and partially because the more efficient we are with our use, the quicker the solar array pays itself off.

I keep a close(r) eye on the Homelab energy usage as it is a source of some contovercy in the household and try as much as possible to keep it under 200W/s. Running:

• TrueNAS [ASRock C2750D4i, 16GB DDR3 ECC, 7x 7200rpm HDD, 1x nvme SSD, 2x Sata SSD]
• Proxmox Node 1 [Lenovo m70q tiny (10th Gen), 64GB DDR4, 1x nvme, 1x Sata SSD]
• Proxmox Node 2 [Dell OptiPlex 3080 (10th Gen), 64GB DDR4, 1x nvme, 1x Sata SSD]
• Unifi UXG Ultra
• Unifi Switch 8 2.5Gb
• Unifi Switch 250 PoE
• Eaton 5P UPS

I tend to notice that running full VM’s on Proxmox has a big impact on power consumption, as compared to running the workload in an LXC container - which I guess is a no brainer.

GitLab vs GiTea

The recent example of this variance was in switching from GitLab to GiTea, I noticed a roughly 15W decrease in my consumption. I thought that this was quite stark. As it was, my GitLab instance was underpowered and often hung on resoueces being in adequate to run the jobs that it needed to.

As much as GiTea has fewer features that GitLab, it is certainly adequate for my needs and I have now migrated my CI/CD process to use Action Runners.

Wazuh VM vs Wazuh LXC

I recently found this awesome write up on running Wazuh on LXC https://wroberts.me/?p=443. I have now powered off my Wazuh instance for both power reasons and because I really didn’t know what I was doing with it. This arctle looks like and excellent up and running which gets you to a level with alerting and pro-active threat remediation. And it is running in LXC.

Docker VM vs Docker LXC

I haven’t looked into this for a while but I believe it can be done and works well. I think it is even possible to run in an unprivileged LXC too. This would allow me to move Mailcow Dockerized onto an LXC which would be very nice.

Workload Scheduling

Another way of saving power would be to schedule various services to only run during daylight hours.

More efficient CPUs

Moving one of my Proxmox nodes from 6th Gen Intel to 10th Gen Intel, running the same workloads, made a power saving. Can I use this to justify moving to even newer generation CPU’s!?