This sets whether file logging is turned on or off for the RMON Ethernet history entries that will be automatically created going forward, per the auto-config-state object. Because this only affects entries created after the setting is changed, not existing ones, an admin who changes this expecting it to also retroactively apply to already-running auto-created history entries on existing ports will be surprised to find those entries unaffected. For example, enabling this with on(1) before adding a new line card means every newly-activated port's auto-created history entry will log to file from the start, while ports activated before the change keep whatever setting was in effect when their entry was created.