- We limited the number of drives to 16 for erasure set because, erasure code shards more than 16 can become chatty and do not have any performance advantages. Additionally since 16 drive erasure set gives you tolerance of 8 drives per object by default which is plenty in any practical scenario.

	if hr.Before.Drives[0].State != madmin.DriveStateMissing {
		t.Fatalf("Unexpected drive state: %v", hr.Before.Drives[0].State)
	}

	// Check the state of all other disks (should be ok)
	for i, h := range append(hr.Before.Drives[1:], hr.After.Drives...) {
		if h.State != madmin.DriveStateOk {
			t.Fatalf("Unexpected drive state (%d): %v", i+1, h.State)
		}
	}

		return config.DefaultHelpPostfix(DefaultKVS, key)
	}

	// Help provides help for config values
	Help = config.HelpKVS{
		config.HelpKV{
			Key:         Bitrot,
			Description: `perform bitrot scan on drives when checking objects during scanner` + defaultHelpPostfix(Bitrot),
			Optional:    true,
			Type:        "on|off",
		},
		config.HelpKV{
			Key:         Sleep,

          "expr": "minio_node_drive_used_bytes{job=~\"$scrape_jobs\",server=\"$server\"}",
          "interval": "",
          "legendFormat": "Used [{{drive}}]",
          "refId": "B"
        },
        {
          "datasource": {
            "type": "prometheus",
            "uid": "${DS_PROMETHEUS}"
          },
          "exemplar": true,

			"Total number of offline drives in current MinIO server instance",
			nil, nil),
		prometheus.GaugeValue,
		float64(offlineDisks.Sum()),
	)

	// MinIO Total Disks per node
	ch <- prometheus.MustNewConstMetric(
		prometheus.NewDesc(
			prometheus.BuildFQName(minioNamespace, "drives", "total"),
			"Total number of drives for current MinIO server instance",
			nil, nil),

		readsPerSec:       "Reads per second on a drive",
		writesPerSec:      "Writes per second on a drive",
		readsKBPerSec:     "Kilobytes read per second on a drive",
		writesKBPerSec:    "Kilobytes written per second on a drive",
		readsAwait:        "Average time for read requests to be served on a drive",
		writesAwait:       "Average time for write requests to be served on a drive",

	globalServiceFreezeCnt int32
	globalServiceFreezeMu  sync.Mutex // Updates.

	// List of local drives to this node, this is only set during server startup,
	// and is only mutated by HealFormat. Hold globalLocalDrivesMu to access.
	globalLocalDrives   []StorageAPI
	globalLocalDrivesMu sync.RWMutex

	globalDriveMonitoring = env.Get("_MINIO_DRIVE_ACTIVE_MONITORING", config.EnableOn) == config.EnableOn

	// Is MINIO_CI_CD set?

	if askDisks == -1 {
		newDisks := getQuorumDisks(disks, infos, (len(disks)+1)/2)
		if newDisks != nil {
			// If we found disks signature in quorum, we proceed to list
			// from a single drive, shuffling of the drives is subsequently.
			disks = newDisks
			askDisks = 1
		} else {
			// If we did not find suitable disks, perform strict quorum listing
			// as no disk agrees on quorum anymore.

			anonNetwork[anonEndpoint] = status
		}
		return anonNetwork
	}

	anonymizeDrives := func(drives []madmin.Disk) []madmin.Disk {
		anonDrives := []madmin.Disk{}
		for _, drive := range drives {
			drive.Endpoint = anonAddr(drive.Endpoint)
			anonDrives = append(anonDrives, drive)
		}
		return anonDrives
	}

	go func() {
		defer xioutil.SafeClose(healthInfoCh)

		Subsystem: "health",
		Name:      "erasure_set_online_drives",
		Help:      "Get the count of the online drives in this erasure set",
		Type:      gaugeMetric,
	}
}

func getClusterErasureSetHealingDrivesMD() MetricDescription {
	return MetricDescription{
		Namespace: clusterMetricNamespace,
		Subsystem: "health",
		Name:      "erasure_set_healing_drives",