systemd-fsck@.service, systemd-fsck-root.service, systemd-fsck — File system checker logic
systemd-fsck@.service
systemd-fsck-root.service
/usr/lib/systemd/systemd-fsck
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 in only if the
root filesystem wasn't checked in the initramfs.
systemd-fsck@.service
is used for all other
file systems and for the root file system in the initramfs.
Those 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 one
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.
systemd-fsck
will forward file system
checking progress to the console. If a file system check fails for
a service without nofail
, emergency mode is
activated, by isolating to
emergency.target
.
systemd-fsck
understands one kernel
command line parameter:
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.
fsck.repair=
¶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.