dcheck(8) [bsd man page]

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)

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

NAME

       icheck - file system storage consistency check

SYNOPSIS

       icheck [ -s ]  [ -b numbers ] [ filesystem ]

DESCRIPTION

       Icheck examines a file system, builds a bit map of used blocks, and compares this bit map against the free list maintained on the file sys-
       tem.  If the file system is not specified, a set of default file systems is checked.  The normal output of icheck includes a report of

	      The total number of files and the numbers of regular, directory, block special and character special files, quota  nodes,  and  sym-
	      bolic links.

	      The total number of blocks in use and the numbers of single-, double-, and triple-indirect blocks and directory blocks.

	      The number of free blocks.

	      The number of blocks missing; i.e. not in any file nor in the free list.

       The  -s option causes icheck to ignore the actual free list and reconstruct a new one by rewriting the super-block of the file system.  The
       file system should be dismounted while this is done; if this is not possible (for example if the root file system has to be salvaged)  care
       should be taken that the system is quiescent and that it is rebooted immediately afterwards so that the old, bad in-core copy of the super-
       block will not continue to be used.  Notice also that the words in the super-block which indicate the size of the free list and of  the	i-
       list  are  believed.   If  the  super-block  has  been curdled these words will have to be patched.  The -s option causes the normal output
       reports to be suppressed.

       Following the -b option is a list of block numbers; whenever any of the named blocks turns up in a file, a diagnostic is produced.

       Icheck is faster if the raw version of the special file is used, since it reads the i-list many blocks at a time.

SEE ALSO

       filsys(5), clri(8), dcheck(8), fsck(8), ncheck(8)

DIAGNOSTICS

       For duplicate blocks and bad blocks (which lie outside the file system) icheck announces the difficulty, the  i-number,	and  the  kind	of
       block  involved.   If a read error is encountered, the block number of the bad block is printed and icheck considers it to contain 0.  `Bad
       freeblock' means that a block number outside the available space was encountered in the free list.  `n dups in free' means  that  n  blocks
       were found in the free list which duplicate blocks either in some file or in the earlier part of the free list.

BUGS

       Since  icheck  is  inherently  two-pass in nature, extraneous diagnostics may be produced if applied to active file systems.  Since default
       file systems vary with installations, icheck should use fstab(5).
       It believes even preposterous super-blocks and consequently can get core images.

3rd Berkeley Distribution														 ICHECK(8)