With Uptime Kuma, I just used ping and http sensors so that I knew my stuff was up. When I switched to CheckMK, I installed the agent on all servers and that brought quite a bit more info in, then I added the Proxmox integration and that gave me the snapshot info (as well as more info). I think it automatically pulled in my ZFS info, like zpool status. Then added smart monitoring to my storage so that I can see that my hard drives have been spinning for 13 years and 266 days 😅