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 sys-
tem 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 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 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 special 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 sys-
tems 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 exam-
ple, 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 sys-
tem. 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 configura-
tion. 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 prob-
lem requiring intervention. This option is
required to enable parallel file system check-
ing.
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 encountering 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 specified.
/etc/vfstab
list of default parameters for each file system
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| 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), vfstab(4), attri-
butes(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.
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 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 attri-
butes have been stripped, the file system is completely
stable on versions of Solaris that are 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.
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