Proxmox Virtual Environment
Posts on Proxmox VE, Proxmox VE Cluster and Puppet management of Proxmox.
I use a combination of Proxmox and Puppet to implement a personal "cloud" service that is more economical to implement than commercial alternatives. The cost of server hardware is constantly decreasing while computing power and capabilities are increasing. Open source software like Proxmox and Puppet is free. The only thing that is complex and expensive is the technical know-how required to harness the power of open source software.
(My venture, SOFIns, addresses the cost and complexity of technical know-how.)