My notes said the cold-spare Proxmox box was sitting in Wake-on-LAN standby. It wasn’t. Here’s how I checked Wake-on-LAN on four Lenovo ThinkCentre Tinys: what ethtool and sysfs tell you, how to find the MAC of a machine that’s off, and why the switch port’s link light is the most honest answer.
When my Raspberry Pi 5 NAS rebooted into kernel 6.12.87, the Radxa Penta SATA HAT’s JMB585 controller failed to initialise and every disk vanished. NFS followed, and my Frigate NVR quietly stopped recording. The fix was one line in config.txt.
A Vevor weather station that can only upload to Weather Underground, a Raspberry Pi 3 pretending to be wunderground.com on its own isolated wifi network, and weewx-interceptor catching the data. Plus the WPA2 handshake that failed nine times out of ten, and the console clock that was an hour fast.
My GPS-disciplined time server dropped off the network and I didn’t find out for 24 days. The cause wasn’t the hardware, and it wasn’t what I assumed twice along the way — it was a permanent DNS record aimed at an address the router was free to hand to somebody else.
A small Proxmox cluster, a managed switch or two, some IP cameras, and Home Assistant eventually stop being a pile of gadgets and start being infrastructure. Here’s how I built observability, a live topology graph, and an AI-assisted ops layer for mine — without letting anything have unsupervised write access to the network.
How a Raspberry Pi 5, a cheap u-blox GPS module, and chrony turned into a home stratum-1 time server — the wiring mistakes, the serial-port gotcha nobody documents, and the PPS upgrade that took accuracy from ±50ms to ±350ns.