const (
	driveUsedBytes               = "used_bytes"
	driveFreeBytes               = "free_bytes"
	driveTotalBytes              = "total_bytes"
	driveUsedInodes              = "used_inodes"
	driveFreeInodes              = "free_inodes"
	driveTotalInodes             = "total_inodes"
	driveTimeoutErrorsTotal      = "timeout_errors_total"
	driveIOErrorsTotal           = "io_errors_total"
	driveAvailabilityErrorsTotal = "availability_errors_total"

| `minio_cluster_health_drives_offline_count`        | `gauge` | Count of offline drives in the cluster         |        |
| `minio_cluster_health_drives_online_count`         | `gauge` | Count of online drives in the cluster          |        |
| `minio_cluster_health_drives_count`                | `gauge` | Count of all drives in the cluster             |        |

	totalInodes    MetricName = "total_inodes"
	readsPerSec    MetricName = "reads_per_sec"
	writesPerSec   MetricName = "writes_per_sec"
	readsKBPerSec  MetricName = "reads_kb_per_sec"
	writesKBPerSec MetricName = "writes_kb_per_sec"
	readsAwait     MetricName = "reads_await"
	writesAwait    MetricName = "writes_await"
	percUtil       MetricName = "perc_util"
	usedInodes     MetricName = "used_inodes"

	// network stats

| `minio_cluster_health_status`                     | Get current cluster health status              |
| `minio_cluster_health_erasure_set_healing_drives` | Count of healing drives in the erasure set     |
| `minio_cluster_health_erasure_set_online_drives`  | Count of online drives in the erasure set      |
| `minio_cluster_health_erasure_set_read_quorum`    | Get read quorum of the erasure set             |

}

func calcCommonWritesDeletes(infos []DiskInfo, readQuorum int) (commonWrite, commonDelete uint64) {
	deletes := make([]uint64, len(infos))
	writes := make([]uint64, len(infos))
	for index, di := range infos {
		deletes[index] = di.Metrics.TotalDeletes
		writes[index] = di.Metrics.TotalWrites
	}

	filter := func(list []uint64) (commonCount uint64) {
		max := 0
		signatureMap := map[uint64]int{}

	beforeDrives := formatsToDrivesInfo(s.endpoints.Endpoints, formats, sErrs)

	res.After.Drives = make([]madmin.HealDriveInfo, len(beforeDrives))
	res.Before.Drives = make([]madmin.HealDriveInfo, len(beforeDrives))
	// Copy "after" drive state too from before.
	for k, v := range beforeDrives {
		res.Before.Drives[k] = v
		res.After.Drives[k] = v
	}

	if countErrs(sErrs, errUnformattedDisk) == 0 {

	return nil, fmt.Errorf("%w (offline-disks=%d/%d)", errErasureReadQuorum, disksNotFound, len(p.readers))
}

// Decode reads from readers, reconstructs data if needed and writes the data to the writer.
// A set of preferred drives can be supplied. In that case they will be used and the data reconstructed.

	diskReserveFraction = 0.15

	// diskAssumeUnknownSize is the size to assume when an unknown size upload is requested.
	diskAssumeUnknownSize = 1 << 30

	// diskMinInodes is the minimum number of inodes we want free on a disk to perform writes.
	diskMinInodes = 1000

	// tlsClientSessionCacheSize is the cache size for client sessions.
	tlsClientSessionCacheSize = 100
)

func init() {

// Supported Storage Class format is "Scheme:Number of parity drives".
// Currently only supported scheme is "EC".
func parseStorageClass(storageClassEnv string) (sc StorageClass, err error) {
	s := strings.Split(storageClassEnv, ":")

	// only two elements allowed in the string - "scheme" and "number of parity drives"
	if len(s) > 2 {

			// all remaining cases imply corrupt data/metadata
			driveState = madmin.DriveStateCorrupt
		}

		result.Before.Drives = append(result.Before.Drives, madmin.HealDriveInfo{
			UUID:     "",
			Endpoint: storageEndpoints[i].String(),
			State:    driveState,
		})
		result.After.Drives = append(result.After.Drives, madmin.HealDriveInfo{
			UUID:     "",
			Endpoint: storageEndpoints[i].String(),
			State:    driveState,
		})