kernel-command-line
systemd
kernel-command-line
7
kernel-command-line
Kernel command line parameters
/proc/cmdline
Description
The kernel, the initial RAM disk (initrd) and
basic userspace functionality may be configured at boot via
kernel command line arguments.
For command line parameters understood by the kernel, please
see
kernel-parameters.html
and
bootparam7.
For command line parameters understood by the initial RAM
disk, please see
dracut.cmdline7,
or the documentation of the specific initrd implementation of your
installation.
Core OS Command Line Arguments
systemd.unit=
rd.systemd.unit=
systemd.dump_core
systemd.crash_chvt
systemd.crash_shell
systemd.crash_reboot
systemd.confirm_spawn
systemd.service_watchdogs
systemd.show_status
systemd.log_target=
systemd.log_level=
systemd.log_location=
systemd.log_color
systemd.default_standard_output=
systemd.default_standard_error=
systemd.setenv=
systemd.machine_id=
systemd.unified_cgroup_hierarchy
systemd.legacy_systemd_cgroup_controller
Parameters understood by the system and service
manager to control system behavior. For details, see
systemd1.
systemd.mask=
systemd.wants=
systemd.debug_shell
Additional parameters understood by
systemd-debug-generator8,
to mask or start specific units at boot, or invoke a debug
shell on tty9.
systemd.restore_state=
This parameter is understood by several system tools
to control whether or not they should restore system state
from the previous boot. For details, see
systemd-backlight@.service8
and
systemd-rfkill.service8.
systemd.volatile=
This parameter controls whether the system shall boot up in volatile mode. Takes a boolean argument, or
the special value state. If false (the default), normal boot mode is selected, the root
directory and /var are mounted as specified on the kernel command line or
/etc/fstab, or otherwise configured. If true, full state-less boot mode is selected. In
this case the root directory is mounted as volatile memory file system (tmpfs), and only
/usr is mounted from the file system configured as root device, in read-only mode. This
enables fully state-less boots were the vendor-supplied OS is used as shipped, with only default
configuration and no stored state in effect, as /etc and /var (as
well as all other resources shipped in the root file system) are reset at boot and lost on shutdown. If this
setting is set to state the root file system is mounted as usual, however
/var is mounted as a volatile memory file system (tmpfs), so that the
system boots up with the normal configuration applied, but all state reset at boot and lost at shutdown. For details,
see
systemd-volatile-root.service8
and
systemd-fstab-generator8.
quiet
Parameter understood by both the kernel and the system
and service manager to control console log verbosity. For
details, see
systemd1.
debug
Parameter understood by both the kernel and the system
and service manager to control console log verbosity. For
details, see
systemd1.
-b
rd.emergency
emergency
rd.rescue
rescue
single
s
S
1
2
3
4
5
Parameters understood by the system and service
manager, as compatibility and convenience options. For details, see
systemd1.
locale.LANG=
locale.LANGUAGE=
locale.LC_CTYPE=
locale.LC_NUMERIC=
locale.LC_TIME=
locale.LC_COLLATE=
locale.LC_MONETARY=
locale.LC_MESSAGES=
locale.LC_PAPER=
locale.LC_NAME=
locale.LC_ADDRESS=
locale.LC_TELEPHONE=
locale.LC_MEASUREMENT=
locale.LC_IDENTIFICATION=
Parameters understood by the system and service
manager to control locale and language settings. For
details, see
systemd1.
fsck.mode=
fsck.repair=
Parameters understood by the file system checker
services. For details, see
systemd-fsck@.service8.
quotacheck.mode=
Parameter understood by the file quota checker
service. For details, see
systemd-quotacheck.service8.
systemd.journald.forward_to_syslog=
systemd.journald.forward_to_kmsg=
systemd.journald.forward_to_console=
systemd.journald.forward_to_wall=
Parameters understood by the journal service. For
details, see
systemd-journald.service8.
vconsole.keymap=
vconsole.keymap_toggle=
vconsole.font=
vconsole.font_map=
vconsole.font_unimap=
Parameters understood by the virtual console setup logic. For details, see
vconsole.conf5.
udev.log_priority=
rd.udev.log_priority=
udev.children_max=
rd.udev.children_max=
udev.exec_delay=
rd.udev.exec_delay=
udev.event_timeout=
rd.udev.event_timeout=
net.ifnames=
Parameters understood by the device event managing
daemon. For details, see
systemd-udevd.service8.
plymouth.enable=
May be used to disable the Plymouth boot splash. For
details, see
plymouth8.
luks=
rd.luks=
luks.crypttab=
rd.luks.crypttab=
luks.name=
rd.luks.name=
luks.uuid=
rd.luks.uuid=
luks.options=
rd.luks.options=
luks.key=
rd.luks.key=
Configures the LUKS full-disk encryption logic at
boot. For details, see
systemd-cryptsetup-generator8.
fstab=
rd.fstab=
Configures the /etc/fstab logic
at boot. For details, see
systemd-fstab-generator8.
root=
rootfstype=
rootflags=
ro
rw
Configures the root file system and its file system
type and mount options, as well as whether it shall be
mounted read-only or read-writable initially. For details,
see
systemd-fstab-generator8.
mount.usr=
mount.usrfstype=
mount.usrflags=
Configures the /usr file system (if required) and
its file system type and mount options. For details, see
systemd-fstab-generator8.
roothash=
systemd.verity=
rd.systemd.verity=
systemd.verity_root_data=
systemd.verity_root_hash=
Configures the integrity protection root hash for the root file system, and other related
parameters. For details, see
systemd-veritysetup-generator8.
systemd.gpt_auto=
rd.systemd.gpt_auto=
Configures whether GPT based partition auto-discovery
shall be attempted. For details, see
systemd-gpt-auto-generator8.
systemd.default_timeout_start_sec=
Overwrites the default start job timeout DefaultTimeoutStartSec= at boot. For details,
see systemd-system.conf5.
systemd.watchdog_device=
Overwrites the watchdog device path WatchdogDevice=. For details, see
systemd-system.conf5.
modules_load=
rd.modules_load=
Load a specific kernel module early at boot. For
details, see
systemd-modules-load.service8.
resume=
Enables resume from hibernation using the specified
device. All
fstab5-like
paths are supported. For details, see
systemd-hibernate-resume-generator8.
systemd.firstboot=
Takes a boolean argument, defaults to on. If off,
systemd-firstboot.service8
will not query the user for basic system settings, even if the system boots up for the first time and the
relevant settings are not initialized yet.
See Also
systemd1,
bootparam7,
dracut.cmdline7,
systemd-debug-generator8,
systemd-fsck@.service8,
systemd-quotacheck.service8,
systemd-journald.service8,
systemd-vconsole-setup.service8,
systemd-udevd.service8,
plymouth8,
systemd-cryptsetup-generator8,
systemd-veritysetup-generator8,
systemd-fstab-generator8,
systemd-gpt-auto-generator8,
systemd-volatile-root.service8,
systemd-modules-load.service8,
systemd-backlight@.service8,
systemd-rfkill.service8,
systemd-hibernate-resume-generator8,
systemd-firstboot.service8