2.11BSD#431 - /usr/man/cat8/dcheck.0

DCHECK(8)	    UNIX Programmer'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 directory, 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 sys-
     tems.  Default file systems vary with installation so dcheck
     should use fstab(5).


Printed 11/24/99						1