fsck(1M)          MISC. REFERENCE MANUAL PAGES           fsck(1M)



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

SYNOPSIS
     fsck [ -F ufs ] [generic_options] [special ...]
     fsck [ -F ufs ]  [generic_options]  [(-y|-Y)|(-n|-N)]  [  -o
     p,b=#,w ] [ special  ....  ]

DESCRIPTION
     generic_options are options supported by  the  generic  fsck
     command.   current_options  are options supported by the s5-
     specific module of the fsck command.

     fsck audits and interactively  repairs  inconsistent  condi-
     tions  on file systems.  In this case, it asks for confirma-
     tion before  attempting  any  corrections.   Inconsistencies
     other  than  those  mentioned above 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:  unrefer-
     enced  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 permission 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  out-
               side 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  direc-
               tory.
          ⊕    Super Block checks:  more blocks for  inodes  than



                        Last change: UFS                        1

fsck(1M)          MISC. REFERENCE MANUAL PAGES           fsck(1M)



               there are in the file system.
          ⊕    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.   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.  The options are:

     -F ufs
          Specifies the ufs-FSType.

     -y | -Y
          Assume a yes response to all questions asked by fsck.

     -n | -N
          Assume a no response to all questions asked by fsck; do
          not open the file system for writing.

     -o   Specify ufs file  system  specific  suboptions.   These
          suboptions can be any combination of the following:

          p    Check the filesystem non-interactively.   Exit  if
               there is a problem requiring intervention.

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

NOTES
     Checking the character special device is almost always  fas-
     ter.

SEE ALSO
     checkfsys(1M),  crash(1M),   generic   fsck(1M),   mkfs(1M),
     ufs(4).












                        Last change: UFS                        2