icheck(8)icheck(8)NAMEicheck - File system storage consistency check
/usr/sbin/icheck [-b numbers] [file system]
The icheck command is obsoleted for normal consistency checking by
The icheck command 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 following items: The total number of files and the numbers of
regular, directory, block special, character special, and fifo files.
The total number of blocks in use and the numbers of single- and dou‐
ble-indirect blocks and directory blocks. The number of free blocks.
The number of blocks missing; that is, not in any file or in any free
A list of block numbers follows the -b option; whenever any of the
named blocks turn up in a file, a diagnostic is produced.
The icheck command is faster if the raw version of the special file is
used since it reads the i-list many blocks at a time.
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 causes a core dump.
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 zero.
Specifies the command path.
Commands: clri(8), fsck(8), ncheck(8)icheck(8)