term% cat index.txt DCHECK(1M) DCHECK(1M)
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.
FILES
Default file systems vary with installation.
SEE ALSO
icheck(1), filsys(5), clri(1), ncheck(1)
DIAGNOSTICS
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 en‐
tries 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 de‐
generate.
BUGS
Since dcheck is inherently two-pass in nature, extraneous diagnostics
may be produced if applied to active file systems.
DCHECK(1M)