func (opts Config) Clone() (int, time.Duration, string) {
	configMutex.RLock()
	defer configMutex.RUnlock()
	return opts.IOCount, opts.Sleep, opts.Bitrot
}

// GetWorkers returns the number of workers, -1 is none configured
func (opts Config) GetWorkers() int {
	configMutex.RLock()
	defer configMutex.RUnlock()
	return opts.DriveWorkers
}

// Update updates opts with nopts
func (opts *Config) Update(nopts Config) {