totalDisks := offlineDisks.Merge(onlineDisks)

	// Report total capacity
	ch <- prometheus.MustNewConstMetric(
		prometheus.NewDesc(
			prometheus.BuildFQName(minioNamespace, "capacity_raw", "total"),
			"Total capacity online in the cluster",
			nil, nil),
		prometheus.GaugeValue,
		float64(GetTotalCapacity(server.Disks)),
	)

	// Report total capacity free
	ch <- prometheus.MustNewConstMetric(
		prometheus.NewDesc(

}

const (
	healthCapacityRawTotalBytes    = "capacity_raw_total_bytes"
	healthCapacityRawFreeBytes     = "capacity_raw_free_bytes"
	healthCapacityUsableTotalBytes = "capacity_usable_total_bytes"
	healthCapacityUsableFreeBytes  = "capacity_usable_free_bytes"
)

var (
	healthCapacityRawTotalBytesMD = NewGaugeMD(healthCapacityRawTotalBytes,
		"Total cluster raw storage capacity in bytes")

type rebalanceStats struct {
	InitFreeSpace uint64 `json:"initFreeSpace" msg:"ifs"` // Pool free space at the start of rebalance
	InitCapacity  uint64 `json:"initCapacity" msg:"ic"`   // Pool capacity at the start of rebalance

	Buckets           []string      `json:"buckets" msg:"bus"`           // buckets being rebalanced or to be rebalanced

		// Should not be set unless there are different handlers for the same HandlerID.
		Subroute string

		// OutCapacity is the output capacity. If <= 0 capacity will be 1.
		OutCapacity int

		// InCapacity is the output capacity.
		// If == 0 no input is expected
		InCapacity int
	}
)

type subHandlerID [32]byte

func makeSubHandlerID(id HandlerID, subRoute string) subHandlerID {

	s3MetricNamespace        MetricNamespace = "minio_s3"
)

const (
	cacheSubsystem            MetricSubsystem = "cache"
	capacityRawSubsystem      MetricSubsystem = "capacity_raw"
	capacityUsableSubsystem   MetricSubsystem = "capacity_usable"
	driveSubsystem            MetricSubsystem = "drive"
	interfaceSubsystem        MetricSubsystem = "if"
	memSubsystem              MetricSubsystem = "mem"

| `minio_cluster_capacity_usable_free_bytes`   | Total free usable capacity online in the cluster.              |
| `minio_cluster_capacity_usable_total_bytes`  | Total usable capacity online in the cluster.                   |
| `minio_cluster_objects_size_distribution`    | Distribution of object sizes across a cluster                  |

| `minio_cluster_health_capacity_raw_total_bytes`    | `gauge` | Total cluster raw storage capacity in bytes    |        |
| `minio_cluster_health_capacity_raw_free_bytes`     | `gauge` | Total cluster raw storage free in bytes        |        |
| `minio_cluster_health_capacity_usable_total_bytes` | `gauge` | Total cluster usable storage capacity in bytes |        |

}

// NewBytes returns a new Bytes.
// A slice is preallocated.
func NewBytes() *Bytes {
	b := Bytes(GetByteBuffer()[:0])
	return &b
}

// NewBytesCap returns an empty Bytes with the given capacity.
func NewBytesCap(size int) *Bytes {
	b := Bytes(GetByteBufferCap(size))
	return &b
}

// NewBytesWith returns a new Bytes with the provided content.

            "type": "prometheus",
            "uid": "${DS_PROMETHEUS}"
          },
          "exemplar": true,
          "expr": "topk(1, sum(minio_cluster_capacity_usable_total_bytes{job=~\"$scrape_jobs\"}) by (instance)) - topk(1, sum(minio_cluster_capacity_usable_free_bytes{job=~\"$scrape_jobs\"}) by (instance))",
          "format": "time_series",
          "instant": false,
          "interval": "1m",

	if capwidth > 0 && capwidth < 64 {
		panic("buffer capped with smaller than 64 bytes is not supported")
	}
	if capwidth > 0 && width > capwidth {
		panic("buffer length cannot be > capacity of the buffer")
	}
	return &BytePoolCap{
		c:    make(chan []byte, maxSize),
		w:    width,
		wcap: capwidth,
	}
}

// Populate - populates and pre-warms the byte pool, this function is non-blocking.