DCHECK(8) System Manager's Manual DCHECK(8)
dcheck - file system directory consistency check
/usr/etc/dcheck [ -i numbers ] [ filesystem ]
Note: dcheck has been superseded for normal consistency checking by
dcheck reads the directories in a file system and compares the link-
count in each inode with the number of directory entries by which it is
referenced. If the file system is not specified, dcheck checks a set
of default file systems.
dcheck is fastest if the raw version of the special file is used, since
the i-list is read in large chunks.
numbers is 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.
Default file systems vary with installation.
fs(5), fsck(8), clri(8), icheck(8), ncheck(8)
When a file turns up for which the link-count and the number of direc-
tory 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
Since dcheck is inherently two-pass in nature, extraneous diagnostics
may be produced if applied to active file systems.
Inode numbers less than 2 are invalid.
9 September 1987 DCHECK(8)