Sun Microsystems Sun Workstation 100U System Manager's Manual page 194

ICHECK(8)
MAINTENANCE COMMANDS
ICHECK( 8)
NAME
icheck - file system storage consistency check
SYNOPSIS
/ulr /ete/leheek ( __
J
(-b
numbers) ( filesystem ]
DESCRIPTION
FILES
N.B.I Icheck is obsoleted for normal consistency checking by /8ck(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, directory, block special and charac-
ter special files.
The total number of blocks in use and the numbers of single-, double-, and triple-indirect
blocks and directory blocks.
The number
or
free blocks.
The number of blocks missing; i.e. not in any file nor in the free list.
The
-II
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; it 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. It the super-block has
been curdled these words will have to be patched. The
- I
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.
Default file systems vary with installation.
SEE ALSO
fsck(8), dcheck(8), ncheck(8), fs(5), clri(8)
DIAGNOSTICS
BUGS
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. It a read error is encountered, the block
number or the bad block is printed and icheck considers it to contain
o.
'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.
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.
The system should be fixed so that the reboot after fixing the root file system is not necessary .
SUD
Release 1.1
Last change: 4 February 1983 39