float64(GetTotalUsableCapacity(server.Disks, sinfo)),
	)

	// Report total usable capacity free
	ch <- prometheus.MustNewConstMetric(
		prometheus.NewDesc(
			prometheus.BuildFQName(minioNamespace, "capacity_usable_free", "total"),
			"Total free usable capacity online in current MinIO server instance",
			nil, nil),
		prometheus.GaugeValue,
		float64(GetTotalUsableCapacityFree(server.Disks, sinfo)),
	)