fsck(1M) manual page
Table of Contents
fsck - check and repair file systems
fsck [ -F FSType ] [
-m ] [ -V ] [ special ... ]
fsck [ -F FSType ] [ - n | N | y | Y ] [ -V ] [ -o FSType-specific-options ] [
special ... ]
SUNWcsu
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 corrective actions will result in loss of data. The
amount and severity of data loss may 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/c1d0s7. 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 systems listed in 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.
- -FFSType
- 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 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 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 intervention.
This option is required to enable parallel file system checking.
- w
- Check
writable file systems only.
- file system is okay and does not need checking
- erroneous parameters
are specified
- file system is unmounted and needs checking (fsck -m only)
- file system is already mounted
- cannot stat device
- uncorrectable errors
detected - terminate normally
- a signal was caught during processing
- uncorrectable
errors detected - terminate immediately
- for root, same as 0.
- /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
clri(1M)
, crash(1M)
, fsck_cachefs(1M)
, fsck_s5fs(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)
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.
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?
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