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

       icheck - file system storage consistency check

       /usr/etc/icheck [ -s ] -b numbers ] [ filesystem ]

       Note:  icheck  has  been  superseded for normal consistency checking by

       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.  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; that is, not in any  file  nor  in
              the free list.

       With the -s option icheck ignores the actual free list and reconstructs
       a new one by rewriting the superblock 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 superblock will not
       continue  to  be  used.   Notice  also that the words in the superblock
       which indicate the size  of  the  free  list  and  of  the  i-list  are
       believed.   If the superblock has been curdled these words will have to
       be patched.  The -s option suppresses the normal output reports.

       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.

       fs(5), clri(8), dcheck(8), fsck(8), ncheck(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.

       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

       Since icheck is inherently two-pass in nature,  extraneous  diagnostics
       may be produced if applied to active file systems.

       It believes even preposterous superblocks and consequently can get core

       The system should be fixed so that the reboot  after  fixing  the  root
       file system is not necessary.

                               9 September 1987                      ICHECK(8)