K3s deployment experiences on Hetzner Cloud and Raspberry Pi

Technical implementations of k3s Kubernetes clusters have been documented across different hardware environments, highlighting varying levels of stability and ease of use.

On Hetzner Cloud, a high-availability (HA) k3s cluster was successfully deployed using ARM instances and HA etcd. The setup utilized a private network with a specific subnet, employing a custom Hetzner cloud controller and Longhorn for storage instead of local storage. The configuration involved disabling Traefik and using flannel pointed toward the private network interface.

In contrast, an attempt to run a k3s cluster with embedded etcd on Raspberry Pi 5 nodes proved unreliable. While intended to provide lower power consumption and physical separation, the setup suffered from high latency and fragility. The primary cause was identified as SD card write endurance; the write-heavy nature of etcd operations led to significant latency spikes on the microSD cards, making the cluster less reliable than a single-node virtual machine setup.