Provided by: e2fsprogs_1.40.8-2ubuntu2_i386 bug

NAME

       fsck - check and repair a Linux file system

SYNOPSIS

       fsck  [  -sAVRTMNP  ] [ -C [ fd ] ] [ -t fstype ] [filesys ... ] [--] [
       fs-specific-options ]

DESCRIPTION

       fsck is used to check and optionally repair  one  or  more  Linux  file
       systems.   filesys can be a device name (e.g.  /dev/hdc1, /dev/sdb2), a
       mount point (e.g.  /, /usr, /home), or an ext2 label or UUID  specifier
       (e.g.     UUID=8868abf6-88c5-4a83-98b8-bfc24057f7bd   or   LABEL=root).
       Normally, the fsck program will try to handle filesystems on  different
       physical  disk  drives  in  parallel to reduce the total amount of time
       needed to check all of the filesystems.

       If no filesystems are specified on the command line, and the -A  option
       is  not  specified,  fsck  will  default  to  checking  filesystems  in
       /etc/fstab serially.  This is equivalent to the -As options.

       The exit code returned by fsck is the sum of the following conditions:
            0    - No errors
            1    - File system errors corrected
            2    - System should be rebooted
            4    - File system errors left uncorrected
            8    - Operational error
            16   - Usage or syntax error
            32   - Fsck canceled by user request
            128  - Shared library error
       The exit code returned when multiple file systems are  checked  is  the
       bit-wise OR of the exit codes for each file system that is checked.

       In  actuality,  fsck  is simply a front-end for the various file system
       checkers (fsck.fstype) available under Linux.  The file system-specific
       checker  is  searched for in /sbin first, then in /etc/fs and /etc, and
       finally in the directories listed in  the  PATH  environment  variable.
       Please  see  the  file system-specific checker manual pages for further
       details.

OPTIONS

       -s     Serialize fsck operations.  This is  a  good  idea  if  you  are
              checking  multiple  filesystems  and  the  checkers  are  in  an
              interactive mode.  (Note: e2fsck(8) runs in an interactive  mode
              by  default.   To  make e2fsck(8) run in a non-interactive mode,
              you must either specify the -p or -a option,  if  you  wish  for
              errors to be corrected automatically, or the -n option if you do
              not.)

       -t fslist
              Specifies the type(s) of file system to be checked.  When the -A
              flag  is  specified,  only  filesystems  that  match  fslist are
              checked.  The fslist parameter  is  a  comma-separated  list  of
              filesystems  and  options specifiers.  All of the filesystems in
              this comma-separated list may be prefixed by a negation operator
              ’no’  or  ’!’,  which  requests  that only those filesystems not
              listed in fslist will be checked.  If all of the filesystems  in
              fslist  are not prefixed by a negation operator, then only those
              filesystems listed in fslist will be checked.

              Options  specifiers  may  be  included  in  the  comma-separated
              fslist.   They  must  have  the  format  opts=fs-option.   If an
              options  specifier  is  present,  then  only  filesystems  which
              contain  fs-option  in  their  mount options field of /etc/fstab
              will be checked.  If the options  specifier  is  prefixed  by  a
              negation  operator, then only those filesystems that do not have
              fs-option in their mount options field  of  /etc/fstab  will  be
              checked.

              For example, if opts=ro appears in fslist, then only filesystems
              listed in /etc/fstab with the ro option will be checked.

              For compatibility with Mandrake distributions whose boot scripts
              depend  upon an unauthorized UI change to the fsck program, if a
              filesystem type of loop is found in fslist, it is treated as  if
              opts=loop were specified as an argument to the -t option.

              Normally,  the  filesystem  type  is  deduced  by  searching for
              filesys in the  /etc/fstab  file  and  using  the  corresponding
              entry.   If  the  type  can  not be deduced, and there is only a
              single filesystem given as an argument to the  -t  option,  fsck
              will  use  the  specified  filesystem type.  If this type is not
              available, then the default file system type (currently ext2) is
              used.

       -A     Walk  through  the  /etc/fstab  file  and  try to check all file
              systems in one run.  This option  is  typically  used  from  the
              /etc/rc system initialization file, instead of multiple commands
              for checking a single file system.

              The root filesystem will be checked first unless the  -P  option
              is  specified  (see  below).   After  that,  filesystems will be
              checked in the order specified  by  the  fs_passno  (the  sixth)
              field  in  the  /etc/fstab  file.   Filesystems with a fs_passno
              value of 0 are skipped and are not checked at all.   Filesystems
              with  a  fs_passno value of greater than zero will be checked in
              order, with filesystems with the lowest fs_passno  number  being
              checked  first.  If there are multiple filesystems with the same
              pass number, fsck  will  attempt  to  check  them  in  parallel,
              although it will avoid running multiple filesystem checks on the
              same physical disk.

              Hence, a very common configuration in /etc/fstab files is to set
              the  root  filesystem  to have a fs_passno value of 1 and to set
              all other filesystems to have a fs_passno value of 2.  This will
              allow  fsck to automatically run filesystem checkers in parallel
              if it is advantageous to do  so.   System  administrators  might
              choose  not  to  use  this  configuration  if they need to avoid
              multiple filesystem checks running in parallel for  some  reason
              ---  for  example, if the machine in question is short on memory
              so that excessive paging is a concern.

       -C [  fd  ]
              Display completion/progress bars for those  filesystem  checkers
              (currently  only  for  ext2 and ext3) which support them.   Fsck
              will manage the filesystem checkers so that  only  one  of  them
              will  display  a  progress  bar  at  a time.  GUI front-ends may
              specify a file descriptor fd, in which  case  the  progress  bar
              information will be sent to that file descriptor.

       -M     Do  not  check  mounted filesystems and return an exit code of 0
              for mounted filesystems.

       -N     Don’t execute, just show what would be done.

       -P     When the -A flag is set, check the root filesystem  in  parallel
              with the other filesystems.  This is not the safest thing in the
              world to do, since if the root filesystem  is  in  doubt  things
              like  the  e2fsck(8) executable might be corrupted!  This option
              is mainly  provided  for  those  sysadmins  who  don’t  want  to
              repartition  the  root filesystem to be small and compact (which
              is really the right solution).

       -R     When checking all file systems with the -A flag, skip  the  root
              file system (in case it’s already mounted read-write).

       -T     Don’t show the title on startup.

       -V     Produce  verbose  output,  including  all  file  system-specific
              commands that are executed.

       fs-specific-options
              Options which are not understood  by  fsck  are  passed  to  the
              filesystem-specific  checker.   These  arguments  must  not take
              arguments, as there is no way for fsck to be  able  to  properly
              guess which arguments take options and which don’t.

              Options  and  arguments  which follow the -- are treated as file
              system-specific options to be passed to the file system-specific
              checker.

              Please  note  that  fsck  is  not  designed  to pass arbitrarily
              complicated options to filesystem-specific checkers.  If  you’re
              doing something complicated, please just execute the filesystem-
              specific checker directly.   If  you  pass  fsck  some  horribly
              complicated  option  and  arguments,  and it doesn’t do what you
              expect, dont bother reporting  it  as  a  bug.   You’re  almost
              certainly doing something that you shouldn’t be doing with fsck.

       Options to different filesystem-specific fsck’s are  not  standardized.
       If  in  doubt,  please consult the man pages of the filesystem-specific
       checker.  Although not guaranteed, the following options are  supported
       by most file system checkers:

       -a     Automatically  repair the file system without any questions (use
              this option with caution).  Note that e2fsck(8) supports -a  for
              backwards compatibility only.  This option is mapped to e2fsck’s
              -p option which is safe to use, unlike the -a option  that  some
              file system checkers support.

       -n     For  some filesystem-specific checkers, the -n option will cause
              the fs-specific fsck to avoid attempting to repair any problems,
              but  simply report such problems to stdout.  This is however not
              true  for  all  filesystem-specific  checkers.   In  particular,
              fsck.reiserfs(8)  will  not  report any corruption if given this
              option.  fsck.minix(8) does not support the -n option at all.

       -r     Interactively repair the  filesystem  (ask  for  confirmations).
              Note:  It is generally a bad idea to use this option if multiple
              fsck’s are being run  in  parallel.   Also  note  that  this  is
              e2fsck’s default behavior; it supports this option for backwards
              compatibility reasons only.

       -y     For some filesystem-specific checkers, the -y option will  cause
              the  fs-specific  fsck  to  always  attempt  to fix any detected
              filesystem corruption automatically.  Sometimes an expert may be
              able  to do better driving the fsck manually.  Note that not all
              filesystem-specific  checkers   implement   this   option.    In
              particular fsck.minix(8) and fsck.cramfs(8) does not support the
              -y option as of this writing.

AUTHOR

       Theodore Ts’o (tytso@mit.edu)

FILES

       /etc/fstab.

ENVIRONMENT VARIABLES

       The fsck program’s behavior is affected by  the  following  environment
       variables:

       FSCK_FORCE_ALL_PARALLEL
              If  this  environment  variable is set, fsck will attempt to run
              all of the specified  filesystems  in  parallel,  regardless  of
              whether  the filesystems appear to be on the same device.  (This
              is useful for RAID systems or high-end storage systems  such  as
              those sold by companies such as IBM or EMC.)

       FSCK_MAX_INST
              This  environment variable will limit the maximum number of file
              system checkers that can be running at one  time.   This  allows
              configurations  which have a large number of disks to avoid fsck
              starting too many file system  checkers  at  once,  which  might
              overload  CPU  and memory resources available on the system.  If
              this value is zero, then an unlimited number of processes can be
              spawned.   This is currently the default, but future versions of
              fsck may attempt to automatically determine how many file system
              checks  can  be  run based on gathering accounting data from the
              operating system.

       PATH   The PATH environment  variable  is  used  to  find  file  system
              checkers.   A  set  of  system  directories  are searched first:
              /sbin, /sbin/fs.d, /sbin/fs, /etc/fs, and /etc.  Then the set of
              directories found in the PATH environment are searched.

       FSTAB_FILE
              This  environment  variable  allows  the system administrator to
              override the standard location of the /etc/fstab  file.   It  is
              also useful for developers who are testing fsck.

SEE ALSO

       fstab(5),   mkfs(8),   fsck.ext2(8)   or   fsck.ext3(8)  or  e2fsck(8),
       cramfsck(8), fsck.minix(8),  fsck.msdos(8),  fsck.jfs(8),  fsck.nfs(8),
       fsck.vfat(8), fsck.xfs(8), fsck.xiafs(8), reiserfsck(8).