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

    NAME
         dcheck - file system directory consistency check

    SYNOPSIS
         dcheck [ -i numbers ] [ filesystem ]

    DESCRIPTION
         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  re-
         ported.

         The  program  is  fastest  if the raw version of the special
         file is used, since the i-list is read in large chunks.

    FILES
         Currently, /dev/rrk2 and /dev/rrp0 are the default file sys-
         tems.

    DIAGNOSTICS
         When a file turns up for which the link-count and the number
         of directory entries disagree, the relevant  facts  are  re-
         ported.   Allocated files which have 0 link-count and no en-
         tries are also listed.  The only dangerous situation  occurs
         when  there  are more entries than links; if entries are re-
         moved, 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.

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

    BUGS
         Since dcheck is inherently two-pass  in  nature,  extraneous
         diagnostics  may  be produced if applied to active file sys-
         tems.

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