CORE OS COMMAND LINE ARGUMENTS¶
systemd.unit=, rd.systemd.unit=,
systemd.dump_core, systemd.crash_chvt,
systemd.crash_shell, systemd.crash_action=,
systemd.confirm_spawn, systemd.service_watchdogs,
systemd.show_status, systemd.status_unit_format=,
systemd.log_target=, systemd.log_level=,
systemd.log_location=, systemd.log_color,
systemd.log_ratelimit_kmsg, systemd.default_standard_output=,
systemd.default_standard_error=, systemd.setenv=,
systemd.machine_id=, systemd.set_credential=,
systemd.set_credential_binary=, systemd.import_credentials=,
systemd.reload_limit_interval_sec=,
systemd.reload_limit_burst=
Parameters understood by the system and service manager
to control system behavior. For details, see
systemd(1).
Added in version 186.
systemd.mask=, systemd.wants=,
systemd.debug_shell, systemd.default_debug_tty=
Additional parameters understood by
systemd-debug-generator(8), to mask or start specific units at boot, or
invoke a debug shell on tty9.
Added in version 215.
systemd.run=, systemd.run_success_action=,
systemd.run_failure_action=
Additional parameters understood by
systemd-run-generator(8), to run a command line specified on the kernel
command line as system service after booting up.
Added in version 240.
systemd.early_core_pattern=
During early boot, the generation of core dump files is
disabled until a core dump handler (if any) takes over. This parameter allows
specifying an absolute path where core dump files should be stored until a
handler is installed. The path should be absolute and may contain specifiers,
see
core(5) for details.
Added in version 240.
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@.service(8) and
systemd-rfkill.service(8).
Added in version 209.
systemd.ssh_auto=, systemd.ssh_listen=
These parameters are interpreted by
systemd-ssh-generator(8) and may be used to control SSH sockets the
system shall be reachable on.
Added in version 256.
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 read-only, 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. If
this setting is set to "overlay" the root file system is set up as
"overlayfs" mount combining the read-only root directory with a
writable "tmpfs", so that no modifications are made to disk, but the
file system may be modified nonetheless with all changes being lost at reboot.
For details, see
systemd-volatile-root.service(8) and
systemd-fstab-generator(8).
Added in version 233.
quiet
Parameter understood by both the kernel and the system
and service manager to control console log verbosity. For details, see
systemd(1).
Added in version 186.
debug
Parameter understood by both the kernel and the system
and service manager to control console log verbosity. For details, see
systemd(1).
Added in version 205.
-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).
Added in version 186.
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).
Added in version 186.
fsck.mode=, fsck.repair=
Parameters understood by the file system checker
services. For details, see
systemd-fsck@.service(8).
Added in version 186.
quotacheck.mode=
Parameter understood by the file quota checker service.
For details, see
systemd-quotacheck.service(8).
Added in version 186.
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).
Added in version 186.
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.conf(5).
Added in version 186.
udev.log_level=, rd.udev.log_level=,
udev.children_max=, rd.udev.children_max=,
udev.exec_delay=, rd.udev.exec_delay=,
udev.event_timeout=, rd.udev.event_timeout=,
udev.timeout_signal=, rd.udev.timeout_signal=,
udev.blockdev_read_only, rd.udev.blockdev_read_only,
net.ifnames=, net.naming_scheme=
Parameters understood by the device event managing
daemon. For details, see
systemd-udevd.service(8).
Added in version 186.
plymouth.enable=
May be used to disable the Plymouth boot splash. For
details, see
plymouth(8).
Added in version 186.
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-generator(8).
Added in version 186.
fstab=, rd.fstab=
Configures the /etc/fstab logic at boot. For details, see
systemd-fstab-generator(8).
Added in version 186.
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-write initially. For details, see
systemd-fstab-generator(8).
If root= is not set (or set to "gpt-auto") the
automatic root partition discovery implemented by
systemd-gpt-auto-generator(8) will be in effect. In this case
rootfstype=, rootflags=, ro, rw will be
interpreted by systemd-gpt-auto-generator.
Added in version 215.
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-generator(8).
Added in version 235.
veritytab=, rd.veritytab=, roothash=,
systemd.verity=, rd.systemd.verity=,
systemd.verity_root_data=, systemd.verity_root_hash=,
systemd.verity.root_options=, usrhash=,
systemd.verity_usr_data=, systemd.verity_usr_hash=,
systemd.verity_usr_options=
Configures the integrity protection root hash for the
root and /usr file systems, and other related parameters. For details, see
systemd-veritysetup-generator(8).
Added in version 233.
systemd.getty_auto=
Configures whether the serial-getty@.service will run.
For details, see
systemd-getty-generator(8).
Added in version 250.
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).
Added in version 215.
systemd.image_policy=, rd.systemd.image_policy=
When GPT-based partition auto-discovery is used,
configures the image dissection policy string to apply, as per
systemd.image-policy(7). For details see
systemd-gpt-auto-generator(8).
Added in version 254.
systemd.default_timeout_start_sec=
Overrides the default start job timeout
DefaultTimeoutStartSec= at boot. For details, see
systemd-system.conf(5).
Added in version 230.
systemd.default_device_timeout_sec=
Overrides the default device timeout
DefaultDeviceTimeoutSec= at boot. For details, see
systemd-system.conf(5).
Added in version 254.
systemd.watchdog_device=
Overrides the watchdog device path
WatchdogDevice=. For details, see
systemd-system.conf(5).
Added in version 236.
systemd.watchdog_sec=
Overrides the watchdog timeout settings otherwise
configured with
RuntimeWatchdog=,
RebootWatchdog= and
KExecWatchdogSec=. Takes a time value (if no unit is specified, seconds
is the implicitly assumed time unit) or the special strings "off" or
"default". For details, see
systemd-system.conf(5).
Added in version 250.
systemd.watchdog_pre_sec=
Overrides the watchdog pre-timeout settings otherwise
configured with
RuntimeWatchdogPreSec=. Takes a time value (if no unit
is specified, seconds is the implicitly assumed time unit) or the special
strings "off" or "default". For details, see
systemd-system.conf(5).
Added in version 251.
systemd.watchdog_pretimeout_governor=
Overrides the watchdog pre-timeout settings otherwise
configured with
RuntimeWatchdogPreGovernor=. Takes a string value. For
details, see
systemd-system.conf(5).
Added in version 251.
systemd.cpu_affinity=
Overrides the CPU affinity mask for the service manager
and the default for all child processes it forks. This takes precedence over
CPUAffinity=, see
systemd-system.conf(5) for details.
Added in version 245.
modules_load=, rd.modules_load=
Load a specific kernel module early at boot. For details,
see
systemd-modules-load.service(8).
Added in version 187.
nameserver=, domain=
Configures DNS server information and search domains, see
systemd-resolved.service(8) for details.
Added in version 253.
resume=, resumeflags=
Enable resume from hibernation using the specified device
and timeout options. All
fstab(5)-style device identifiers are
supported. For details, see
systemd-hibernate-resume-generator(8).
Added in version 217.
resume_offset=
Configure the page offset of the swap space from the
resume device. For details, see
systemd-hibernate-resume-generator(8).
Added in version 254.
systemd.firstboot=
Takes a boolean argument, defaults to on. If off,
systemd-firstboot.service(8) and
systemd-homed-firstboot.service(1) 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. Not to be confused with
systemd.condition_first_boot= (see below), which overrides the result
of the
ConditionFirstBoot= unit file condition, and thus controls more
than just systemd-firstboot.service behaviour.
Added in version 233.
systemd.condition_needs_update=
Takes a boolean argument. If specified, overrides the
result of
ConditionNeedsUpdate= unit condition checks. See
systemd.unit(5) for details.
Added in version 246.
systemd.condition_first_boot=
Takes a boolean argument. If specified, overrides the
result of
ConditionFirstBoot= unit condition checks. See
systemd.unit(5) for details. Not to be confused with
systemd.firstboot= which only controls behaviour of the
systemd-firstboot.service system service but has no effect on the condition
check (see above).
Added in version 246.
systemd.clock_usec=
Takes a decimal, numeric timestamp in μs since
January 1st 1970, 00:00am, to set the system clock to. The system time is set
to the specified timestamp early during boot. It is not propagated to the
hardware clock (RTC).
Added in version 246.
systemd.random_seed=
Takes a base64 encoded random seed value to credit with
full entropy to the kernel's random pool during early service manager
initialization. This option is useful in testing environments where delays due
to random pool initialization in entropy starved virtual machines shall be
avoided.
Note that if this option is used the seed is accessible to
unprivileged programs from /proc/cmdline. This option is hence a security
risk when used outside of test systems, since the (possibly) only seed used
for initialization of the kernel's entropy pool might be easily acquired by
unprivileged programs.
It is recommended to pass 512 bytes of randomized data (as that
matches the Linux kernel pool size), which may be generated with a command
like the following:
dd if=/dev/urandom bs=512 count=1 status=none | base64 -w 0
Again: do not use this option outside of testing environments,
it's a security risk elsewhere, as secret key material derived from the
entropy pool can possibly be reconstructed by unprivileged programs.
Added in version 246.
systemd.allow_userspace_verity=
Takes a boolean argument. Controls whether disk images
that are Verity protected may be authenticated in userspace signature checks
via /etc/verity.d/ (and related directories) public key drop-ins, or whether
in-kernel signature checking only. Defaults to on.
Added in version 256.
systemd.hostname=
Accepts a hostname to set during early boot. If specified
takes precedence over what is set in /etc/hostname. Note that this does not
bar later runtime changes to the hostname, it simply controls the initial
hostname set during early boot.
Added in version 246.
systemd.tty.term.tty=,
systemd.tty.rows.tty=,
systemd.tty.columns.tty=
These arguments allow configuring default values for
$TERM,
TTYRows=, and
TTYColumns= for tty
tty.
Additionally,
systemd.tty.term.console will configure the
$TERM
value used by
systemd if not set explicitly using
TERM on the
kernel command line. The tty name should be specified without the /dev/ prefix
(e.g. "systemd.tty.rows.ttyS0=80").
Added in version 254.
systemd.battery_check=
Accepts a boolean argument. If false the boot-time
battery charge check implemented by
systemd-battery-check.service(8) is
disabled.
Added in version 254.
ifname=, net.ifname_policy=
Controls interface naming policies, implemented by
systemd-network-generator.service(8).
Added in version 245.
systemd.tpm2_wait=
Controls whether to wait for a TPM2 device at boot,
implemented by
systemd-tpm2-generator(8).
Added in version 256.
