DCHECK(VIII)                 2/8/75                  DCHECK(VIII)


     dcheck - file system directory consistency check


     dcheck [ -i numbers ] [ filesystem ]


     Dcheck reads the directories in a file system  and  compares

     the  link-count  in each i-node with the number of directory

     entries by which it is referenced.  If the  file  system  is

     not specified, a set of default file systems is checked.

     The -i flag is followed by a list of i-numbers; when one  of

     those  i-numbers turns up in a directory, the number, the i-

     number of the directory, and  the  name  of  the  entry  are


     The program is fastest if the raw  version  of  the  special

     file is used, since the i-list is read in large chunks.


     Currently, /dev/rrk2 and  /dev/rrp0  are  the  default  file



     When a file turns up for which the link-count and the number

     of  directory  entries  disagree,  the  relevant  facts  are

     reported.  Allocated files which have 0  link-count  and  no

     entries  are  also  listed.   The  only  dangerous situation

     occurs when there are more entries than  links;  if  entries

     are  removed,  so  the  link-count drops to 0, the remaining

     entries point to thin air.  They should  be  removed.   When

     there  are more links than entries, or there is an allocated

     file with neither links nor entries, some disk space may  be

     lost but the situation will not degenerate.


     icheck (VIII), fs (V), clri (VIII), ncheck (VIII)


     Since dcheck is inherently two-pass  in  nature,  extraneous

     diagnostics  may  be  produced  if  applied  to  active file