Is a Cluster with Two Raspberry Pis and One SSD Practical?

It really depends on what you plan to do! If it's for learning purposes, your setup makes perfect sense. You might not achieve the most efficient performance, especially with one node on SD, but it's a solid starting point. Just remember, for anything mission-critical or if you hope to have high availability, you may want to scale up to at least three nodes in the future, ideally with SSDs.

Great question! Many tutorials use single hosts with virtual machines because not everyone has multiple physical nodes available for testing. It's easier to show concepts that way. In a home lab, you fit as much as you can on one machine while tolerating some downtime for learning. However, for production workloads, you'd want a more robust setup to avoid single points of failure. Learning with clusters, even if virtual, can provide a richer understanding of networking and deployment.

Your question hits the nail on the head! It's a good starting point for both learning and practical experimentation. Just be aware that having fewer than three control nodes can lead to downtime when you try to upgrade your OS or Kubernetes. So while clustering with your current setup is feasible, it's good practice to aim for more nodes down the line.

For home use, your setup could work just fine! You can have one Raspberry Pi as the control node and the other as a worker. However, keep in mind that having only two nodes limits your fault tolerance. If you want to ensure high availability, you really should aim for three control plane nodes. Also, mixing architectures like ARM on the Pis and x86 on the laptop can complicate things a bit, as you'd need to manage compatibility across different systems.