The review of #129 found false alarms and a silent failure: the NVMe temperature bit, old-age attributes, a fan's minimum or latched alarm, an unrelated hot sensor and a board chip's limits could raise a condition, while a hung smartctl stopped the fans' looks and an old readings file passed as healthy. Read spinning drives hourly (smartd too) so a read never keeps one from spinning down, and skip a drive that cannot say whether it sleeps.