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fsck(8) [osx man page]

FSCK(8) 						    BSD System Manager's Manual 						   FSCK(8)

NAME
fsck -- filesystem consistency check and interactive repair SYNOPSIS
fsck -p [-f] fsck [-l maxparallel] [-q] [-y] [-n] [-d] DESCRIPTION
The first form of fsck preens a standard set of filesystems or the specified filesystems. It is normally used in the script /etc/rc during automatic reboot. Here fsck reads the filesystem descriptor table (using getfsent(3)) to determine which filesystems to check. Only parti- tions that have ``rw,'' ``rq'' or ``ro'' as options, and that have non-zero pass number are checked. Filesystems with pass number 1 (nor- mally just the root filesystem) are checked one at a time. When pass 1 completes, all remaining filesystems are checked, running one process per disk drive. The disk drive containing each filesystem is inferred from the shortest prefix of the device name that ends in one or more digits; the remaining characters are assumed to be the partition designator. In preening mode, filesystems that are marked clean are skipped. Filesystems are marked clean when they are unmounted, when they have been mounted read-only, or when fsck runs on them success- fully. It should be noted that fsck is now essentially a wrapper that invokes other fsck_XXX utilities as needed. Currently, fsck can invoke fsck_hfs, fsck_msdos, fsck_exfat, and fsck_udf. If this underlying process that fsck invokes encounters serious inconsistencies or the filesystem type is not one of the above, it exits with an abnormal return status and an automatic reboot will then fail. For each corrected inconsistency one or more lines will be printed identifying the filesystem on which the correction will take place, and the nature of the correction. If sent a QUIT signal, fsck will finish the filesystem checks, then exit with an abnormal return status that causes an automatic reboot to fail. This is useful when you want to finish the filesystem checks during an automatic reboot, but do not want the machine to come up multi- user after the checks complete. Without the -p option, fsck audits and interactively repairs inconsistent conditions for filesystems. It should be noted that some of the corrective actions which are not correctable under the -p option will result in some loss of data. The amount and severity of data lost may be determined from the diagnostic output. If the operator does not have write permission on the filesystem fsck will default to a -n action. The following flags are interpreted by fsck and passed along to the underlying tool that it spawns. -f Force fsck to check `clean' filesystems when preening. -l Limit the number of parallel checks to the number specified in the following argument. By default, the limit is the number of disks, running one process per disk. If a smaller limit is given, the disks are checked round-robin, one filesystem at a time. -p "Preen" mode, described above. -q Do a quick check to determine if the filesystem was unmounted cleanly. -y Assume a yes response to all questions asked by fsck; this should be used with great caution as this is a free license to con- tinue after essentially unlimited trouble has been encountered. -n Assume a no response to all questions asked by fsck except for 'CONTINUE?', which is assumed to be affirmative; do not open the filesystem for writing. If no filesystems are given to fsck then a default list of filesystems is read using getfsent(3). Because of inconsistencies between the block device and the buffer cache, the raw device should always be used. SEE ALSO
fs(5), fsck_hfs(8), fsck_msdos(8), getfsent(3), reboot(8) 4th Berkeley Distribution May 18, 2010 4th Berkeley Distribution

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FSCK(8) 						    BSD System Manager's Manual 						   FSCK(8)

NAME
fsck -- file system consistency check and interactive repair SYNOPSIS
fsck [-dfnPpqvy] [-l maxparallel] [-T fstype:fsoptions] [-t fstype] [-x mountpoint] [special | node ...] DESCRIPTION
The fsck command invokes file system-specific programs to check the special devices listed in the fstab(5) file or in the command line for consistency. It is normally used in the script /etc/rc during automatic reboot. If no file systems are specified, and ``preen'' mode is enabled ( -p option) fsck reads the table /etc/fstab to determine which file systems to check, in what order. Only partitions in fstab that are mounted ``rw,'' ``rq'' or ``ro'' and that have non-zero pass number are checked. File systems with pass number 1 (normally just the root file sys- tem) are checked one at a time. When pass 1 completes, all remaining file systems are checked, running one process per disk drive. By default, file systems which are already mounted read-write are not checked. The disk drive containing each file system is inferred from the longest prefix of the device name that ends in a digit; the remaining characters are assumed to be the partition designator. The options are as follows: -d Debugging mode. Just print the commands without executing them. -f Force checking of file systems, even when they are marked clean (for file systems that support this), or when they are mounted read- write. -l maxparallel Limit the number of parallel checks to the number specified in the following argument. By default, the limit is the number of disks, running one process per disk. If a smaller limit is given, the disks are checked round-robin, one file system at a time. -n Causes fsck to assume no as the answer to all operator questions, except "CONTINUE?". -P Display a progress meter for each file system check. This option also disables parallel checking. Note that progress meters are not supported by all file system types. -p Enter preen mode. In preen mode, fsck will check all file systems listed in /etc/fstab according to their pass number, and will make minor repairs without human intervention. -q Quiet mode, do not output any messages for clean filesystems. -T fstype:fsoptions List of comma separated file system specific options for the specified file system type, in the same format as mount(8). -t fstype Invoke fsck only for the comma separated list of file system types. If the list starts with ``no'' then invoke fsck for the file system types that are not specified in the list. -v Print the commands before executing them. -x mountpoint Exclude the filesystem which has a mountpoint the same as in /etc/fstab. Used only in ``preen'' mode. -y Causes fsck to assume yes as the answer to all operator questions. FILES
/etc/fstab file system table EXIT STATUS
fsck exits with 0 on success. Any major problems will cause fsck to exit with the following non-zero exit(3) codes, so as to alert any invoking program or script that human intervention is required. 1 Usage problem. 2 Unresolved errors while checking the filesystem. Re-running fsck on the filesystem(s) is required. 4 The root filesystem was changed in the process of checking, and updating the mount was unsuccessful. A reboot (without sync) is required. 8 The filesystem check has failed, and a subsequent check is required that will require human intervention. 12 fsck exited because of the result of a signal (usually SIGINT or SIGQUIT from the terminal). SEE ALSO
fstab(5), fsck_ext2fs(8), fsck_ffs(8), fsck_lfs(8), fsck_msdos(8), mount(8) BSD
February 17, 2010 BSD
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