}
		storageLogOnceIf(GlobalContext, err, "check-format-json") // log unexpected errors
		return nil, errCorruptedBackend
	}
	return fi, nil
}

// GetDiskID - returns the cached disk uuid
func (s *xlStorage) GetDiskID() (string, error) {
	s.RLock()
	diskID := s.diskID
	fileInfo := s.formatFileInfo
	lastCheck := s.formatLastCheck

	for _, s := range z.serverPools {
		for _, set := range s.sets {
			for _, disk := range set.getDisks() {
				if disk == OfflineDisk {
					continue
				}
				if id, _ := disk.GetDiskID(); id != "" {
					if _, ok := idMap[id]; ok {
						res = append(res, disk)
					}
				}
			}
		}
	}
	return res
}