Shawn Sesna discusses his ongoing experiences with building a Raspberry Pi cluster, focusing on the upgrades and lessons learned since his last post. He has expanded his cluster from five to eight Raspberry Pi machines by switching to a 24-port switch, allowing him to divide them between Docker Swarm and Kubernetes. Sesna highlights the challenge of running containers on ARM architecture, noting that while the Raspberry Pi 4 has a 64-bit processor, the Raspberry Pi OS remains 32-bit, prompting him to use a 64-bit version of Ubuntu. He successfully deployed ARM64 compatible MySQL containers in his Kubernetes cluster to modernize his database management, offering a solution to the limitations of outdated MySQL containers. Additionally, Sesna shares his preference for using Portainer over Visualizer for better monitoring and management of his Docker Swarm, enhancing his understanding of Linux, Docker, and Kubernetes during the COVID-19 pandemic.