Failed router update

What Happened

A routine OPNsense update from 26.1.11 to 26.7 failed mid-install — the new kernel archive never extracted, but the updater rebooted anyway. The firewall came back with no kernel to boot, hanging early with a vidconsole is invalid message and no network, taking every service behind it offline.

The Fix

With no remote console on the hardware, recovery required booting from an OPNsense installer USB into its rescue shell, importing the ZFS pool, backing up the firewall config to a second USB, and restoring the previous kernel that the failed update had thankfully left behind (kernel.old). That got the system bootable again on a temporary mismatched state, after which a normal update completed the job and brought everything current.

Impact & Takeaway

No configuration or data was lost — the failure never touched the config, only the base/kernel install step. Total downtime was a few hours, spent entirely on physical, on-site recovery. The main takeaway: an update that reboots automatically even after a failed step can leave a system worse off than not updating at all, and out-of-band access (IPMI/serial) would have made this far less painful to diagnose.