drivesCount    int
		expectedData   int
		expectedParity int
	}{
		{RRS, 16, 14, 2},
		{STANDARD, 16, 8, 8},
		{"", 16, 8, 8},
		{RRS, 16, 9, 7},
		{STANDARD, 16, 10, 6},
		{"", 16, 9, 7},
	}
	for i, tt := range tests {
		scfg := Config{
			Standard: StorageClass{
				Parity: 8,
			},
			RRS: StorageClass{
				Parity: 2,
			},
			initialized: true,
		}

	if len(cfg.Standard.String()) == 0 && len(cfg.RRS.String()) == 0 {
		// Do not enable storage-class if no settings found.
		return
	}
	s[config.StorageClassSubSys][config.Default] = config.KVS{
		config.KV{
			Key:   ClassStandard,
			Value: cfg.Standard.String(),
		},
		config.KV{
			Key:   ClassRRS,
			Value: cfg.RRS.String(),
		},
	}

	configStandardParityMD = NewGaugeMD(configStandardParity,
		"Standard storage class parity")
)

// loadClusterConfigMetrics - `MetricsLoaderFn` for cluster config
// such as standard and RRS parity.
func loadClusterConfigMetrics(ctx context.Context, m MetricValues, c *metricsCache) error {
	clusterDriveMetrics, err := c.clusterDriveMetrics.Get()
	if err != nil {
		metricsLogIf(ctx, err)
	} else {

MINIO_STORAGE_CLASS_RRS: Format "EC:<Default_Parity_Reduced_Redundancy_Class>" (e.g. "EC:3"). This sets the number of parity drives for MinIO server in Reduced Redundancy mode. Objects are stored in Reduced Redundancy mode, if Put request specifies RRS storage class
Refer to the link https://github.com/minio/minio/tree/master/docs/erasure/storage-class for more information`,
	)

	ErrUnexpectedBackendVersion = newErrFn(
		"Backend version seems to be too recent",

		ignoreInUse, _ = strconv.ParseBool(forceStr)
	}

	// Disallow remote tiers with internal storage class names
	switch cfg.Name {
	case storageclass.STANDARD, storageclass.RRS:
		writeErrorResponseJSON(ctx, w, toAdminAPIErr(ctx, errTierReservedName), r.URL)
		return
	}

	// Refresh from the disk in case we had missed notifications about edits from peers.