If you have a mix of Proxmox nodes and external servers, getting a clean, truthful view of CPU, memory and disk is strangely hard. Proxmox’s built-in charts blur the line between free, cached and used memory, which makes planning resources awkward. I also needed email alerts for low disk space and high CPU or memory after learning the hard way that a full disk can freeze VMs and turn recovery into a risky dance. Finally, I wanted all nodes in one place, not just Proxmox, but remote KVMs, VPSs and dedicated servers from various providers.