1KERNEL-COMMAND-LINE(7) kernel-command-line KERNEL-COMMAND-LINE(7)
2
6 kernel-command-line - Kernel command line parameters
7
9 /proc/cmdline
10
12 The kernel, the initial RAM disk (initrd) and basic userspace
13 functionality may be configured at boot via kernel command line
14 arguments.
15 For command line parameters understood by the kernel, please see
17 kernel-parameters.html[1] and bootparam(7).
18 For command line parameters understood by the initial RAM disk, please
20 see dracut.cmdline(7), or the documentation of the specific initrd
21 implementation of your installation.
22
24 systemd.unit=, rd.systemd.unit=, systemd.dump_core,
25 systemd.early_core_pattern=, systemd.crash_chvt, systemd.crash_shell,
26 systemd.crash_reboot, systemd.confirm_spawn, systemd.service_watchdogs,
27 systemd.show_status, systemd.status_unit_format=, systemd.log_target=,
28 systemd.log_level=, systemd.log_location=, systemd.log_color,
29 systemd.default_standard_output=, systemd.default_standard_error=,
30 systemd.setenv=, systemd.machine_id=, systemd.unified_cgroup_hierarchy,
31 systemd.legacy_systemd_cgroup_controller
32 Parameters understood by the system and service manager to control
33 system behavior. For details, see systemd(1).
34 systemd.mask=, systemd.wants=, systemd.debug_shell
36 Additional parameters understood by systemd-debug-generator(8), to
37 mask or start specific units at boot, or invoke a debug shell on
38 tty9.
39 systemd.run=, systemd.run_success_action=, systemd.run_failure_action=
41 Additional parameters understood by systemd-run-generator(8), to
42 run a command line specified on the kernel command line as system
43 service after booting up.
44 systemd.early_core_pattern=
46 During early boot, the generation of core dump files is disabled
47 until a core dump handler (if any) takes over. This parameter
48 allows to specifies an absolute path where core dump files should
49 be stored until a handler is installed. The path should be absolute
50 and may contain specifiers, see core(5) for details.
51 systemd.restore_state=
53 This parameter is understood by several system tools to control
54 whether or not they should restore system state from the previous
55 boot. For details, see systemd-backlight@.service(8) and systemd-
56 rfkill.service(8).
57 systemd.volatile=
59 This parameter controls whether the system shall boot up in
60 volatile mode. Takes a boolean argument, or the special value
61 "state". If false (the default), normal boot mode is selected, the
62 root directory and /var are mounted as specified on the kernel
63 command line or /etc/fstab, or otherwise configured. If true, full
64 state-less boot mode is selected. In this case the root directory
65 is mounted as volatile memory file system ("tmpfs"), and only /usr
66 is mounted from the file system configured as root device, in
67 read-only mode. This enables fully state-less boots were the
68 vendor-supplied OS is used as shipped, with only default
69 configuration and no stored state in effect, as /etc and /var (as
70 well as all other resources shipped in the root file system) are
71 reset at boot and lost on shutdown. If this setting is set to
72 "state" the root file system is mounted read-only, however /var is
73 mounted as a volatile memory file system ("tmpfs"), so that the
74 system boots up with the normal configuration applied, but all
75 state reset at boot and lost at shutdown. If this setting is set to
76 "overlay" the root file system is set up as "overlayfs" mount
77 combining the read-only root directory with a writable "tmpfs", so
78 that no modifications are made to disk, but the file system may be
79 modified nonetheless with all changes being lost at reboot. For
80 details, see systemd-volatile-root.service(8) and systemd-fstab-
81 generator(8).
82 quiet
84 Parameter understood by both the kernel and the system and service
85 manager to control console log verbosity. For details, see
86 systemd(1).
87 debug
89 Parameter understood by both the kernel and the system and service
90 manager to control console log verbosity. For details, see
91 systemd(1).
92 -b, rd.emergency, emergency, rd.rescue, rescue, single, s, S, 1, 2, 3,
94 4, 5
95 Parameters understood by the system and service manager, as
96 compatibility and convenience options. For details, see systemd(1).
97 locale.LANG=, locale.LANGUAGE=, locale.LC_CTYPE=, locale.LC_NUMERIC=,
99 locale.LC_TIME=, locale.LC_COLLATE=, locale.LC_MONETARY=,
100 locale.LC_MESSAGES=, locale.LC_PAPER=, locale.LC_NAME=,
101 locale.LC_ADDRESS=, locale.LC_TELEPHONE=, locale.LC_MEASUREMENT=,
102 locale.LC_IDENTIFICATION=
103 Parameters understood by the system and service manager to control
104 locale and language settings. For details, see systemd(1).
105 fsck.mode=, fsck.repair=
107 Parameters understood by the file system checker services. For
108 details, see systemd-fsck@.service(8).
109 quotacheck.mode=
111 Parameter understood by the file quota checker service. For
112 details, see systemd-quotacheck.service(8).
113 systemd.journald.forward_to_syslog=, systemd.journald.forward_to_kmsg=,
115 systemd.journald.forward_to_console=, systemd.journald.forward_to_wall=
116 Parameters understood by the journal service. For details, see
117 systemd-journald.service(8).
118 vconsole.keymap=, vconsole.keymap_toggle=, vconsole.font=,
120 vconsole.font_map=, vconsole.font_unimap=
121 Parameters understood by the virtual console setup logic. For
122 details, see vconsole.conf(5).
123 udev.log_priority=, rd.udev.log_priority=, udev.children_max=,
125 rd.udev.children_max=, udev.exec_delay=, rd.udev.exec_delay=,
126 udev.event_timeout=, rd.udev.event_timeout=, net.ifnames=,
127 net.naming-scheme=
128 Parameters understood by the device event managing daemon. For
129 details, see systemd-udevd.service(8).
130 plymouth.enable=
132 May be used to disable the Plymouth boot splash. For details, see
133 plymouth(8).
134 luks=, rd.luks=, luks.crypttab=, rd.luks.crypttab=, luks.name=,
136 rd.luks.name=, luks.uuid=, rd.luks.uuid=, luks.options=,
137 rd.luks.options=, luks.key=, rd.luks.key=
138 Configures the LUKS full-disk encryption logic at boot. For
139 details, see systemd-cryptsetup-generator(8).
140 fstab=, rd.fstab=
142 Configures the /etc/fstab logic at boot. For details, see systemd-
143 fstab-generator(8).
144 root=, rootfstype=, rootflags=, ro, rw
146 Configures the root file system and its file system type and mount
147 options, as well as whether it shall be mounted read-only or
148 read-write initially. For details, see systemd-fstab-generator(8).
149 mount.usr=, mount.usrfstype=, mount.usrflags=
151 Configures the /usr file system (if required) and its file system
152 type and mount options. For details, see systemd-fstab-
153 generator(8).
154 roothash=, systemd.verity=, rd.systemd.verity=,
156 systemd.verity_root_data=, systemd.verity_root_hash=
157 Configures the integrity protection root hash for the root file
158 system, and other related parameters. For details, see systemd-
159 veritysetup-generator(8).
160 systemd.gpt_auto=, rd.systemd.gpt_auto=
162 Configures whether GPT based partition auto-discovery shall be
163 attempted. For details, see systemd-gpt-auto-generator(8).
164 systemd.default_timeout_start_sec=
166 Overwrites the default start job timeout DefaultTimeoutStartSec= at
167 boot. For details, see systemd-system.conf(5).
168 systemd.watchdog_device=
170 Overwrites the watchdog device path WatchdogDevice=. For details,
171 see systemd-system.conf(5).
172 modules_load=, rd.modules_load=
174 Load a specific kernel module early at boot. For details, see
175 systemd-modules-load.service(8).
176 resume=, resumeflags=
178 Enables resume from hibernation using the specified device and
179 mount options. All fstab(5)-like paths are supported. For details,
180 see systemd-hibernate-resume-generator(8).
181 systemd.firstboot=
183 Takes a boolean argument, defaults to on. If off, systemd-
184 firstboot.service(8) will not query the user for basic system
185 settings, even if the system boots up for the first time and the
186 relevant settings are not initialized yet.
187
189 systemd(1), systemd-system.conf(5), bootparam(7), dracut.cmdline(7),
190 systemd-debug-generator(8), systemd-fsck@.service(8), systemd-
191 quotacheck.service(8), systemd-journald.service(8), systemd-vconsole-
192 setup.service(8), systemd-udevd.service(8), plymouth(8), systemd-
193 cryptsetup-generator(8), systemd-veritysetup-generator(8), systemd-
194 fstab-generator(8), systemd-gpt-auto-generator(8), systemd-volatile-
195 root.service(8), systemd-modules-load.service(8), systemd-
196 backlight@.service(8), systemd-rfkill.service(8), systemd-hibernate-
197 resume-generator(8), systemd-firstboot.service(8)
198
200 1. kernel-parameters.html
201 https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html
202systemd 243 KERNEL-COMMAND-LINE(7)