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fsck(8) [osx man page]

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

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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SYSTEMD-FSCK@.SERVICE(8)				       systemd-fsck@.service					  SYSTEMD-FSCK@.SERVICE(8)

systemd-fsck@.service, systemd-fsck-root.service, systemd-fsck - File system checker logic SYNOPSIS
systemd-fsck@.service systemd-fsck-root.service /lib/systemd/systemd-fsck DESCRIPTION
systemd-fsck@.service and systemd-fsck-root.service are services responsible for file system checks. They are instantiated for each device that is configured for file system checking. systemd-fsck-root.service is responsible for file system checks on the root file system, but only if the root filesystem was not checked in the initramfs. systemd-fsck@.service is used for all other file systems and for the root file system in the initramfs. These services are started at boot if passno in /etc/fstab for the file system is set to a value greater than zero. The file system check for root is performed before the other file systems. Other file systems may be checked in parallel, except when they are on the same rotating disk. systemd-fsck does not know any details about specific filesystems, and simply executes file system checkers specific to each filesystem type (/sbin/fsck.*). This helper will decide if the filesystem should actually be checked based on the time since last check, number of mounts, unclean unmount, etc. If a file system check fails for a service without nofail, emergency mode is activated, by isolating to KERNEL COMMAND LINE
systemd-fsck understands these kernel command line parameters: fsck.mode= One of "auto", "force", "skip". Controls the mode of operation. The default is "auto", and ensures that file system checks are done when the file system checker deems them necessary. "force" unconditionally results in full file system checks. "skip" skips any file system checks. One of "preen", "yes", "no". Controls the mode of operation. The default is "preen", and will automatically repair problems that can be safely fixed. "yes" will answer yes to all questions by fsck and "no" will answer no to all questions. SEE ALSO
systemd(1), fsck(8), systemd-quotacheck.service(8), fsck.btrfs(8), fsck.cramfs(8), fsck.ext4(8), fsck.fat(8), fsck.hfsplus(8), fsck.minix(8), fsck.ntfs(8), fsck.xfs(8) systemd 237 SYSTEMD-FSCK@.SERVICE(8)
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