* contains a media info for a media that is not on the same media as the media
  info.

* parameters:
  * 1st form:
    Method:      Method (media info) to handle the media.
    TargetMedia: specifies the media to which the media info belongs;
    * qualifiers:
      * device:,
      * file:,

      * lvm(<vg>/<lv>):,
        * 'lvm(<vg>/<lv>):/dev/sda'
          NOTES='logical volume is finally specified by "METHOD"'
          # '<vg>/<lv>' is used with "CHECK" on the delegated media.

      * partition<N>:,
        * 'partition2:/dev/sda'
          NOTES='partition is finally specified by "METHOD"'
          # 'partition2:' is used with "CHECK" on the delegated media.
      * uuid: .

  * 2nd form:
    TargetMedia: specifies the media to which the media info belongs;
    UUID: ...
    * Method (media info) is on the target media;
    * make a symbolic link from "TargetMedia" to "UUID".