The ODS-2 Disk and File Utilities is a high performance utility
 developed to perform routine maintenance and special purpose operations
 on disks, files and directories. The functionality offered by DFU
 is not or partly available through other DCL commands or VMS utilities.

 DFU has the following functions:

   o DEFRAGMENT : defragment individual files
   o DELETE     : delete files by file-id, and delete directory(trees) fast
   o DIRECTORY functions
                : COMPRESS , DUMP or RECOVER directories
                : search directories for files with multiple versions ,
                   alias files , or empty directories
   o INDEXF     : analyze , defragment truncate and extend INDEXF.SYS
   o REPORT     : reports disk fragmentation
   o SEARCH     : search for files
   o SET        : set file attributes
   o UNDELETE   : recover deleted files
   o VERIFY     : analyze (and repair) the disk structure