Runtime-only config mode is a temporary mode where the commands you enter do not automatically become part of the saved FortiGate configuration. This enables you to make changes with the knowledge that you can revert to the saved configuration if there are problems.

NOTE: Backup your configuration before experimenting with this feature. Otherwise you may lose your working configuration data.

The commands related to Runtime-only config mode are:

config system global
  set cfg-save { automatic | manual | revert }
  set cfg-revert-timeout <seconds>
end

execute cfg reload
execute cfg save

The default setting for cfg-save is automatic mode where CLI commands become part of the saved unit configuration as soon as you execute them by entering either next or end.

In manual mode, commands take effect but do not become part of the saved configuration unless you execute the execute cfg save command. When the FortiGate unit restarts, the FortiGate unit loads the saved configuration. Configuration changes that were not saved are lost.

Revert mode is manual mode plus, if the administrative session is idle for more than a specified timeout period, the FortiGate unit will reboot using the last saved configuration. You set the timeout delay in system global using the set cfg-revert-timeout command.