ICHECK(8) GENIX Programmer's Manual ICHECK(8)
NAME
icheck - file system storage consistency check
SYNOPSIS
/etc/icheck [ -s ] [ -b numbers ] [ filesystem ]
DESCRIPTION
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 list 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, direc-
tory, 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 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 sys-
tem. 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.
FILES
Default file systems vary with installation.
SEE ALSO
fsck(8), dcheck(8), ncheck(8), filsys(5), clri(8)
Printed 11/16/83 1
ICHECK(8) GENIX Programmer's Manual ICHECK(8)
DIAGNOSTICS
For duplicate blocks and bad blocks (which lie outside the file sys-
tem) 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 diagnos-
tics may be produced if applied to active file systems.
It believes even preposterous super-blocks and consequently can get
core images.
The system should be fixed so that the reboot after fixing the root
file system is not necessary.
Printed 11/16/83 2