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 sys-
tem conditions. If the file system is inconsistent the default action for each correction is to wait for the userto respond yes or no. If the user does not have write per-
mission fsck defaults to a no action. Some corrective
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 orkeyword-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 special 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 sys-
tems listed in /etc/vfstab. Those entries in /etc/vfstabwhich 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 exam-
ple, ufs, some file systems eligible for checking may bechecked in parallel. Consult the file system-specific man
page (for example, fsck_ufs(1M)) for more information.
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System Administration Commands fsck(1M)
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 formounting, 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 thecommand. This option may be used to verify and to vali-
date the command line.-v
Enables verbose output. Might not be supported by allfilesystem-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=nSunOS 5.11 Last change: 7 May 2008 2
System Administration Commands fsck(1M)
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 blocksby running newfs(1M) with the -Nv options specified.
cIf the file system is in the old (static table) for-
mat, convert it to the new (dynamic table) format. If the file system is in the new format, convert itto the old format provided the old format can sup-
port the file system configuration. In interactivemode, 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 anddone if possible without user interaction. Conver-
sion 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 withpre-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. pCheck 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 OKSunOS 5.11 Last change: 7 May 2008 3
System Administration Commands fsck(1M)
1 erroneous parameters are specified 32file system is unmounted and needs checking (fsck -m
only) 33 file system is already mounted 34 cannot stat device 35a filesystem that is mounted read/write was modified -
reboot 36uncorrectable errors detected - terminate normally
37 a signal was caught during processing 39uncorrectable errors detected - terminate immediately
40file 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.SunOS 5.11 Last change: 7 May 2008 4
System Administration Commands fsck(1M)
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 systemATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | SUNWcs ||_____________________________|_____________________________|
| 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), attri-
butes(5), largefile(5), ufs(7FS) WARNINGSThe 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. Forthis 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 immediatelyafter 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.SunOS 5.11 Last change: 7 May 2008 5
System Administration Commands fsck(1M)
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 arenot 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 attri-
butes have been stripped, the file system is completelystable on versions of Solaris that are not attribute-aware,
but would be considered corrupted on attribute-aware ver-
sions. In the latter circumstance, run the attribute-aware
fsck to stabilize the file system before using it in an
attribute-aware environment.
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