systemd-fsck@.service, systemd-fsck-root.service, systemd-fsck - File system
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.*).
These checkers 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 emergency.target.
systemd-fsck understands these kernel command line parameters:
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
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.