ock uuid="" time="0" transaction="1" version="2" data_block_size="%u" nr_data_blocks="%lu">
 <device dev_id="1" mapped_blocks="%lu" transaction="0" creation_time="0" snap_time="0">
  <range_mapping origin_begin="0" data_begin="%lu" length="%lu" time="0"/>
 </device>
</superblock>