A data storage system according to one embodiment includes a head; a drive mechanism for passing a medium over the head; a controller electrically coupled to the head; logic for periodically determining a stopwrite threshold based on a current position error signal sample; logic for determining whether the current position error signal sample exceeds the stopwrite threshold; logic for disabling writing when the current position error signal sample exceeds the stopwrite threshold; and logic for enabling writing when the current position error signal sample does not exceed the stopwrite threshold. Additional embodiments are also disclosed.