OPNsense
ZFS-Snapshots
Create a new Snapshot with the name
known-good
Upgrade Firmware
Reboot and test
OPNsense works as expected:
Remove the known-good Snapshot and keep using the default Snapshot
OPNsense has issues:
Activate the
known-good
Snapshot either in the WebGUI or the Boot Menu
After rebooting, remove the bad
default
Snapshot
Rename the
known-good
Snapshot back to
default