func GetTotalCapacityFree(diskInfo []madmin.Disk) (capacity uint64) {
	for _, d := range diskInfo {
		capacity += d.AvailableSpace
	}
	return
}

// GetTotalUsableCapacityFree gets the total usable capacity free in the cluster.
func GetTotalUsableCapacityFree(diskInfo []madmin.Disk, s StorageInfo) (capacity uint64) {
	for _, disk := range diskInfo {
		// Ignore invalid.

	m.Set(healthCapacityUsableTotalBytes, float64(GetTotalUsableCapacity(storageInfo.Disks, storageInfo)))
	m.Set(healthCapacityUsableFreeBytes, float64(GetTotalUsableCapacityFree(storageInfo.Disks, storageInfo)))

	return nil