fsck(1M-ufs)                                                   fsck(1M-ufs)

NAME
     fsck (ufs) - file system consistency check and interactive repair

SYNOPSIS
     fsck [-F ufs] [genericoptions] [special ...]

     fsck [-F ufs] [genericoptions] [-o b=#,w,r] [special ...]

DESCRIPTION
     fsck audits and interactively repairs inconsistent conditions on file
     systems. In this case, it asks for confirmation before attempting any
     corrections. Inconsistencies other than those mentioned below can
     often result in some loss of data. The amount and severity of data
     lost can be determined from the diagnostic output.

     fsck corrects innocuous inconsistencies such as: unreferenced inodes,
     too-large link counts in inodes, missing blocks in the free list,
     blocks appearing in the free list and also in files, or incorrect
     counts in the super block, automatically. It displays a message for
     each inconsistency corrected that identifies the nature of, and file
     system on which, the correction is to take place. After successfully
     correcting a file system, fsck prints the number of files on that file
     system, the number of used and free blocks, and the percentage of
     fragmentation.

     The default action for each correction is to wait for the operator to
     respond either yes or no. If the operator does not have write permis-
     sion on the file system, fsck will default to a -n (no corrections)
     action.

     Inconsistencies checked are as follows:

     -  Blocks claimed by more than one inode or the free list.

     -  Blocks claimed by an inode or the free list outside the range of
        the file system.

     -  Incorrect link counts.

     -  Incorrect directory sizes.

     -  Bad inode format.

     -  Blocks not accounted for anywhere.

     -  Directory checks, file pointing to unallocated inode, inode number
        out of range, absence of "." and ".." as the first two entries in
        each directory.

     -  Super Block checks: more blocks for inodes than there are in the
        file system.




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fsck(1M-ufs)                                                   fsck(1M-ufs)

     -  Bad free block list format.

     -  Total free block and/or free inode count incorrect.

     Orphaned files and directories (allocated but unreferenced) are, with
     the operator's concurrence, reconnected by placing them in the
     lost+found directory. The name assigned is the inode number prepended
     with the following characters "i-". If the lost+found directory does
     not exist, it is created. If there is insufficient space its size is
     increased.

     A file system may be specified by giving the name of the block or
     character special device on which it resides, or by giving the name of
     its mount point.

OPTIONS
     -F ufs              Specifies the ufs-FSType.

     genericoptions     Options supported by the generic fsck command.

     -o                  Specifies the ufs file system specific suboptions.
                         If invalid options are specified, a warning mes-
                         sage is printed and the invalid options are
                         ignored. The following options are available:

                         b=#  Use the block specified as the super block
                              for the file system. Block 32 is always an
                              alternate super block.

                         r    Read-only check of the file system. fsck does
                              not attempt to fix and inconsistencies.

                         w    Only checks those file systems that are
                              designated as read-write in /etc/vfstab.

SEE ALSO
     crash(1M), generic fsck(1M), mkfs(1M), vfstab(4), fs(4-ufs).

















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