code: func (u *volumeUtil) GetFsCapacityByte(fullPath string) (int64, error) {
  	_, capacity, _, _, _, _, err := fs.FsInfo(fullPath)
  	return capacity, err
  }
docs: // GetFsCapacityByte returns capacity in bytes about a mounted filesystem.
  // fullPath is the pathname of any file within the mounted filesystem. Capacity
  // returned here is total capacity.