/LEVEL={n}
       /LEVEL=1 (default)

          The defragmentation process selects files for
          defragmentation (from among those not excluded) based
          on the /LEVEL qualifier. Once a file is selected as
          a candidate, the defragmentation process attempts
          to fully defragment that file (make it 100 percent
          contiguous). Specify the level number as an integer
          ranging from one to five:

          o  /LEVEL=1 (default)

             Any file that is not 100 percent contiguous, or
             can be selected using levels two through four, is
             a candidate for defragmentation.

          o  /LEVEL=2

             Any file whose extents cannot be completely mapped
             by the mapping window, or that can be selected
             using levels three or four, is a candidate for
             defragmentation. The default window value is seven
             and can be set for a given volume using:

             $ SET VOLUME {device-spec}/WINDOWS=[n]

          o  /LEVEL=3

             Any file with retrieval pointers in more than one
             file header, or that can be selected using level
             four, is a candidate for defragmentation.

          o  /LEVEL=4

             The defragmentation process for level 4 processing
             performs only free space consolidation. This level
             is used in conjunction with the /CONSOLIDATE_
             FREESPACE qualifier.

          o  /LEVEL=5

             This level requests a volume analysis only;
             no defragmentation occurs. The statistical
             results are available in the log file, which
             is required when /LEVEL=5 is selected (see the
             /LOG qualifier). If level five is selected, the
             /LEVEL=2 candidate file specifications are listed
             in the full log file.