bsd man page for dcheck

DCHECK(8)						      System Manager's Manual							 DCHECK(8)

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 direc-
       tory, and the name of the entry are reported.

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

SEE ALSO
       filsys(5), clri(8), fsck(8), icheck(8), ncheck(8)

DIAGNOSTICS
       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.

BUGS
       Since dcheck is inherently two-pass in nature, extraneous diagnostics may be produced if applied to active file systems.  Default file sys-
       tems vary with installation so dcheck should use fstab(5).

3rd Berkeley Distribution														 DCHECK(8)