/LOG={file-spec}
       /NOLOG (default)

          The /LOG qualifier causes the defragmentation process
          to create a file containing a list of all its
          operations. The information in the log file varies
          with the presence of the /FULL or /BRIEF qualifiers.
          The /FULL qualifier lists all files analyzed by the
          defragmentation process and reports their disposition
          during each phase of defragmentation. The /BRIEF
          qualifier lists only the statistics of each phase,
          such as number of files analyzed, and number of files
          defragmented.