Raspberry Pi

My control-plane machine vanished for twenty hours. The most useful evidence turned out to be a safety mechanism that did not fire.

The standby for my agent server was designed as a warm standby, formally ratified, amended five times, and thrown out the same day for an always-on mesh with edge steering. That died too, on cost and on a Pi with 905 MB of RAM. What shipped is a dormant cold standby with its own free tunnel, a structural split-brain fence, and a health endpoint that tells the truth about what it cannot do.

The control-plane machine had a config file explicitly setting persistent log storage, and its logs were still vanishing. A vendor file with a higher number won by sort order alone, roughly nine days of history had already rotated away, and half the reported symptom turned out to be my own wrong command.

Moved the public tunnel entrance off the busy compute box onto its own dedicated Raspberry Pi with its own uplink, so a reboot of any other machine can no longer take the whole public site down.