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fsck(1M)		System Administration Commands		      fsck(1M)

NAME
       fsck - check and	repair file systems

SYNOPSIS
       fsck [-F	FSType]	[-m] [-V] [special...]

       fsck  [-F FSType]  [-n  | N | y | Y]  [-V] [-o FSType-specific-options]
       [special...]

DESCRIPTION
       fsck audits and interactively repairs inconsistent file	system	condi-
       tions.  If  the file system is inconsistent the default action for each
       correction is to	wait for the user to respond yes or no.	 If  the  user
       does  not have write permission fsck defaults to	a no action. Some cor-
       rective actions will result in loss of data. The	amount and severity of
       data loss can be	determined from	the diagnostic output.

       FSType-specific-options	are  options  specified	 in  a comma-separated
       (with no	intervening spaces) list of options or keyword-attribute pairs
       for interpretation by the FSType-specific module	of the command.

       special	represents the character special device	on which the file sys-
       tem resides, for	example, /dev/rdsk/c1t0d0s7. Note: the character  spe-
       cial  device,  not  the block special device, should be used. fsck will
       not work	on a block device if it	is mounted.

       If no special device is specified fsck checks the file  systems	listed
       in  /etc/vfstab.	 Those	entries	 in /etc/vfstab	which have a character
       special device entry in the fsckdev field and have a  non-zero  numeric
       entry  in the fsckpass field will be checked. Specifying	-F FSType lim-
       its the file systems to be checked to those of the type indicated.

       If special is specified,	but -F is not, the file	system	type  will  be
       determined  by looking for a matching entry in /etc/vfstab. If no entry
       is found, the default local file	 system	 type  specified  in  /etc/de-
       fault/fs	will be	used.

       If  a  file  system  type supports parallel checking, for example, ufs,
       some file systems eligible for checking may  be	checked	 in  parallel.
       Consult	the  file system-specific man page (for	example, fsck_ufs(1M))
       for more	information.

OPTIONS
       The following generic options are supported:

       -F FSType
	     Specify the file system type on which to operate.

       -m    Check but do not repair. This option checks that the file	system
	     is	 suitable for mounting,	returning the appropriate exit status.
	     If	the file system	is ready for mounting, fsck displays a message
	     such as:

	     ufs fsck: sanity check: /dev/rdsk/c0t3d0s1	okay

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

       -V    Echo the expanded command line but	do not	execute	 the  command.
	     This  option  may	be  used to verify and to validate the command
	     line.

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

       -o specific-options
	     These specific-options can	be any combination  of	the  following
	     separated by commas (with no intervening spaces).

	     b=n   Use	block  n as the	super block for	the file system. Block
		   32 is always	one of the alternate super  blocks.  Determine
		   the	location  of  other  super blocks by running newfs(1M)
		   with	the -Nv	options	specified.

	     c	   If the file system is in the	 old  (static  table)  format,
		   convert  it	to the new (dynamic table) format. If the file
		   system is in	the new	format,	convert	it to the  old	format
		   provided the	old format can support the file	system config-
		   uration.  In	interactive mode, fsck will list the direction
		   the conversion is to	be made	and ask	whether	the conversion
		   should be done. If a	negative answer	is given,  no  further
		   operations  are done	on the file system. In preen mode, the
		   direction of	the conversion is listed and done if  possible
		   without  user interaction. Conversion in preen mode is best
		   used	when all the file systems are being converted at once.
		   The	format	of  a  file  system can	be determined from the
		   first line of output	from fstyp(1M).	 Note: the c option is
		   seldom  used	 and  is  included only	for compatibility with
		   pre-4.1 releases. There is no guarantee  that  this	option
		   will	be included in future releases.

	     f	   Force  checking  of file systems regardless of the state of
		   their super block clean flag.

	     p	   Check and fix the file system non-interactively  ("preen").
		   Exit	 immediately if	there is a problem requiring interven-
		   tion. This option is	required to enable parallel file  sys-
		   tem checking.

	     w	   Check writable file systems only.

EXIT STATUS
       0     file system is okay and does not need checking

       1     erroneous parameters are specified

       32    file system is unmounted and needs	checking (fsck -m only)

       33    file system is already mounted

       34    cannot stat device

       36    uncorrectable errors detected - terminate normally

       37    a signal was caught during	processing

       39    uncorrectable errors detected - terminate immediately

       40    for root, same as 0.

USAGE
       See  largefile(5)  for the description of the behavior of fsck when en-
       countering files	greater	than or	equal to 2 Gbyte (2**31	bytes).

FILES
       /etc/default/fs
	     default local file	system type. Default values can	be set for the
	     following flags in	/etc/default/fs. For example: LOCAL=ufs.

	     LOCAL The	default	partition for a	command	if no FSType is	speci-
		   fied.

       /etc/vfstab
	     list of default parameters	for each file system

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Availability		     |SUNWcsu			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       clri(1M), fsck_cachefs(1M),  fsck_ufs(1M),  fsdb_ufs(1M),  fsirand(1M),
       fstyp(1M),  mkfs(1M),  mkfs_ufs(1M),  mountall(1M),  newfs(1M), reboot(
       1M), fs_ufs(4), vfstab(4), attributes(5), largefile(5)

WARNINGS
       The operating system buffers  file  system  data.  Running  fsck	 on  a
       mounted	file system can	cause the operating system's buffers to	become
       out of date with	respect	to the disk. For this reason, the file	system
       should  be  unmounted  when fsck	is used. If this is not	possible, care
       should be taken that the	system is quiescent and	that  it  is  rebooted
       immediately  after  fsck	is run.	Quite often, however, this will	not be
       sufficient. A panic will	probably occur if running fsck on a file  sys-
       tem modifies the	file system.

NOTES
       This command may	not be supported for all FSTypes.

       Running fsck on file systems larger than	2 Gb fails if the user chooses
       to use the block	interface to the device:

       fsck /dev/dsk/c?t?d?s?

       rather than the raw (character special) device:

       fsck /dev/rdsk/c?t?d?s?

       Starting	with Solaris 9,	fsck manages extended attribute	 data  on  the
       disk.  (See fsattr(5) for a description of extended file	attributes.) A
       file system with	extended attributes can	be mounted on versions of  So-
       laris  that  are	not attribute-aware (versions prior to Solaris 9), but
       the attributes will not be accessible and fsck will strip them from the
       files  and  place  them	in  lost+found.	 Once the attributes have been
       stripped, the file system is completely stable on versions  of  Solaris
       that  are  attribute-aware, but would be	considered corrupted on	attri-
       bute-aware versions. In the latter  circumstance,  run  the  attribute-
       aware  fsck  to	stabilize the file system before using it in an	attri-
       bute-aware environment.

SunOS 5.9			  07 Aug 2001			      fsck(1M)

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXIT STATUS | USAGE | FILES | ATTRIBUTES | SEE ALSO | WARNINGS | NOTES

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