state = madmin.DriveStateRootMount
	case err == nil:
		state = madmin.DriveStateOk
	default:
		state = fmt.Sprintf("%s (cause: %s)", madmin.DriveStateUnknown, err)
	}

	return
}

func getOnlineOfflineDisksStats(disksInfo []madmin.Disk) (onlineDisks, offlineDisks madmin.BackendDisks) {
	onlineDisks = make(madmin.BackendDisks)
	offlineDisks = make(madmin.BackendDisks)

	for _, disk := range disksInfo {

		objLayer := newObjectLayerFn()

		metrics = make([]MetricV2, 0, 50)
		storageInfo := objLayer.LocalStorageInfo(ctx, true)
		onlineDrives, offlineDrives := getOnlineOfflineDisksStats(storageInfo.Disks)
		totalDrives := onlineDrives.Merge(offlineDrives)

		for _, disk := range storageInfo.Disks {
			metrics = append(metrics, MetricV2{
				Description:    getNodeDriveUsedBytesMD(),

		// Calculate the number of online/offline disks of all nodes
		var allDisks []madmin.Disk
		for _, s := range servers {
			allDisks = append(allDisks, s.Disks...)
		}
		onlineDisks, offlineDisks := getOnlineOfflineDisksStats(allDisks)

		backend = madmin.ErasureBackend{
			Type:             madmin.ErasureType,
			OnlineDisks:      onlineDisks.Sum(),
			OfflineDisks:     offlineDisks.Sum(),