Index · Directives systemd 231


kernel-command-line — Kernel command line parameters




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.txt and bootparam(7).

For command line parameters understood by the initial RAM disk, please see dracut.cmdline(7), 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.show_status=, systemd.log_target=, systemd.log_level=, systemd.log_color=, systemd.log_location=, systemd.default_standard_output=, systemd.default_standard_error=, systemd.setenv=, systemd.machine_id=

Parameters understood by the system and service manager to control system behavior. For details, see systemd(1).

systemd.mask=, systemd.wants=, systemd.debug-shell

Additional parameters understood by systemd-debug-generator(8), to mask or start specific units at boot, or invoke a debug shell on tty9.


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@.service(8) and systemd-rfkill.service(8).


Parameter understood by both the kernel and the system and service manager to control console log verbosity. For details, see systemd(1).


Parameter understood by both the kernel and the system and service manager to control console log verbosity. For details, see systemd(1).

-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 systemd(1).

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 systemd(1).


Parameters understood by the file system checker services. For details, see systemd-fsck@.service(8).


Parameter understood by the file quota checker service. For details, see systemd-quotacheck.service(8).

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.service(8).

vconsole.keymap=, vconsole.keymap.toggle=, vconsole.font=,, vconsole.font.unimap=

Parameters understood by the virtual console setup logic. For details, see systemd-vconsole-setup.service(8).

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.service(8).


May be used to disable the Plymouth boot splash. For details, see plymouth(8).

luks=, rd.luks=, luks.crypttab=, rd.luks.crypttab=,,, 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-generator(8).

fstab=, rd.fstab=

Configures the /etc/fstab logic at boot. For details, see systemd-fstab-generator(8).

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-generator(8).

systemd.gpt_auto=, rd.systemd.gpt_auto=

Configures whether GPT based partition auto-discovery shall be attempted. For details, see systemd-gpt-auto-generator(8).


Overwrites the default start job timeout DefaultTimeoutStartSec= at boot. For details, see systemd-system.conf(5).

modules-load=, rd.modules-load=

Load a specific kernel module early at boot. For details, see systemd-modules-load.service(8).


Enables resume from hibernation using the specified device. All fstab(5)-like paths are supported. For details, see systemd-hibernate-resume-generator(8).

See Also

systemd(1), bootparam(7), dracut.cmdline(7), systemd-debug-generator(8), systemd-fsck@.service(8), systemd-quotacheck.service(8), systemd-journald.service(8), systemd-vconsole-setup.service(8), systemd-udevd.service(8), plymouth(8), systemd-cryptsetup-generator(8), systemd-fstab-generator(8), systemd-gpt-auto-generator(8), systemd-modules-load.service(8), systemd-backlight@.service(8), systemd-rfkill.service(8), systemd-hibernate-resume-generator(8)