Copyright (c) 1988, 1993
The Regents of the University of California. All rights reserved.

%sccs.include.proprietary.roff%

@(#)icheck.8 8.1 (Berkeley) 06/05/93

C 4 icheck - file system storage consistency check icheck [ -b numbers ] [ filesystem ] N.B.: Icheck is obsoleted for normal consistency checking by fsck (8).

Icheck examines a file system, builds a bit map of used blocks, and compares this bit map against the free map maintained on the file system. 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. 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 any free map.

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.

Default file systems vary with installation. fsck(8), dcheck(8), ncheck(8), fs(5), clri(8) 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. Since icheck is inherently two-pass in nature, extraneous diagnostics may be produced if applied to active file systems.

It believes even preposterous super-blocks and consequently can get core images.