Performance

TL;DR If you run self-hosted GitHub Actions runners, every actions/cache step is round-tripping to GitHub’s cloud storage. For a homelab cluster with local runners, that means cache restores travel from GitHub’s CDN to your runner, through your ISP, and back – even though the runner is 10 feet from your NAS. I deployed falcondev-oss/github-actions-cache-server as a Kubernetes deployment, pointed it at NFS storage on my NAS, set one environment variable on my runners, and flushed all the GitHub-hosted caches. Zero workflow changes required. ...

TL;DR Prometheus and Grafana both crashed with I/O errors on the same node. Before assuming software, I ran a full hardware audit across all four Proxmox hosts — SMART health, NVMe disk benchmarks (fio), CPU benchmarks (sysbench), memory bandwidth tests, and 10GbE network throughput (iperf3). The result: all hardware is healthy. The I/O errors were Longhorn CSI virtual block device corruption, not physical disk failure. Along the way, I established baseline performance numbers for every subsystem and discovered that custom cooling makes a dramatic difference in thermal performance. ...