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

NAME

       fsck - check and repair file systems

SYNOPSIS

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

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

DESCRIPTION

       fsck  audits  and interactively repairs inconsistent file system conditions. 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 system resides, for example, /dev/rdsk/c1t0d0s7. Note: the character spe-
       cial device, not the block special device, should be used. fsck will not work if the block device 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
       limits 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/default/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.

       -v

	   Enables verbose output. Might not be supported by all filesystem-specific fsck implementations.

       -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 configuration.  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 pos-
	       sible  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 intervention. This
	       option is required to enable parallel file system checking.

	   w

	       Check writable file systems only.

EXIT STATUS

       0

	   file system is unmounted and OK

       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

       35

	   a filesystem that is mounted read/write was modified - reboot

       36

	   uncorrectable errors detected - terminate normally

       37

	   a signal was caught during processing

       39

	   uncorrectable errors detected - terminate immediately

       40

	   file system is mounted read-only and is OK

USAGE

       The fsck command is large file aware for UFS file systems, per the largefile(5) man page.

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 specified.

       /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			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Committed 		   |
       +-----------------------------+-----------------------------+

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), vfstab(4), attributes(5), largefile(5), ufs(7FS)

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 system modifies the file system.

NOTES

       This command may not be supported for all FSTypes.

       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 Solaris 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 not attribute-aware, but would be considered corrupted on
       attribute-aware versions. In the latter circumstance, run the attribute-aware fsck to stabilize the file  system  before  using	it  in	an
       attribute-aware environment.

SunOS 5.11							    7 May 2008								  fsck(1M)