func Enabled(kvs config.KVS) bool {
	ssc := kvs.Get(ClassStandard)
	rrsc := kvs.Get(ClassRRS)
	return ssc != "" || rrsc != ""
}

// DefaultParityBlocks returns default parity blocks for 'drive' count
func DefaultParityBlocks(drive int) int {
	switch drive {
	case 1:
		return 0
	case 3, 2:
		return 1
	case 4, 5:
		return 2
	case 6, 7:
		return 3
	default:
		return 4