9 dracut.cmdline - dracut kernel command line options
13 The root device used by the kernel is specified in the boot configuration
14 file on the kernel command line, as always.
16 The traditional _root=/dev/sda1_ style device specification is allowed, but not
17 encouraged. The root device should better be identified by LABEL or UUID. If a
18 label is used, as in _root=LABEL=<label_of_root>_ the initramfs will search all
19 available devices for a filesystem with the appropriate label, and mount that
20 device as the root filesystem. _root=UUID=<uuidnumber>_ will mount the partition
21 with that UUID as the root filesystem.
23 In the following all kernel command line parameters, which are processed by
24 dracut, are described.
26 "rd.*" parameters mentioned without "=" are boolean parameters. They can be
27 turned on/off by setting them to {0|1}. If the assignment with "=" is missing
28 "=1" is implied. For example _rd.info_ can be turned off with _rd.info=0_ or
29 turned on with _rd.info=1_ or _rd.info_. The last value in the kernel command
30 line is the value, which is honored.
34 **init=**_<path to real init>_::
35 specify the path to the init programm to be started after the initramfs has
38 **root=**_<path to blockdevice>_::
39 specify the block device to use as the root filesystem.
45 root=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
46 root=/dev/disk/by-label/Root
48 root=/dev/disk/by-uuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
49 root=UUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
52 **rootfstype=**_<filesystem type>_:: "auto" if not specified, e.g.:
58 **rootflags=**_<mount options>_::
59 specify additional mount options for the root filesystem. If not set,
60 _/etc/fstab_ of the real root will be parsed for special mount options and
64 do not honor special mount options for the root filesystem found in
65 _/etc/fstab_ of the real root.
69 **rd.driver.blacklist=**_<drivername>[,<drivername>,...]_::
70 do not load kernel module <drivername>. This parameter can be specified
73 **rd.driver.pre=**_<drivername>[,<drivername>,...]_::
74 force loading kernel module <drivername>. This parameter can be specified
77 **rd.driver.post=**_<drivername>[,<drivername>,...]_::
78 force loading kernel module <drivername> after all automatic loading modules
79 have been loaded. This parameter can be specified multiple times.
81 **rd.ctty=**_<terminal>_::
82 if the dracut image was generated with --ctty option, try to spawn an
83 emergency shell on the specified terminal; if rd.ctty is specified without a
84 value or not provided at all, the default is /dev/tty1. The '/dev' prefix
91 print informational output though "quiet" is set
94 allow dropping to a shell, if root mounting fails
97 set -x for the dracut shell and logs to dmesg, console and
98 _/run/initramfs/init.log_
101 drop to a shell at the end
103 **rd.break=**_{cmdline|pre-udev|pre-trigger|initqueue|pre-mount|mount|pre-pivot}_::
104 drop to a shell on defined breakpoint
107 set udev to loglevel info
110 set udev to loglevel debug
114 **vconsole.keymap=**_<keymap base file name>_::
115 keyboard translation table loaded by loadkeys; taken from keymaps directory;
116 will be written as KEYMAP to _/etc/vconsole.conf_ in the initramfs, e.g.:
119 vconsole.keymap=de-latin1-nodeadkeys
122 **vconsole.keymap.ext=**_<list of keymap base file names>_::
123 list of extra keymaps to bo loaded (sep. by space); will be written as
124 EXT_KEYMAP to _/etc/vconsole.conf_ in the initramfs
126 **vconsole.unicode**[=_{0|1}_]::
127 boolean, indicating UTF-8 mode; will be written as UNICODE to
128 _/etc/vconsole.conf_ in the initramfs
130 **vconsole.font=**_<font base file name>_::
131 console font; taken from consolefonts directory; will be written as FONT to
132 _/etc/vconsole.conf_ in the initramfs; e.g.:
135 vconsole.font=LatArCyrHeb-16
138 **vconsole.font.map=**_<console map base file name>_::
139 see description of '-m' parameter in setfont manual; taken from consoletrans
140 directory; will be written as FONT_MAP to _/etc/vconsole.conf_ in the
143 **vconsole.font.unimap=**_<unicode table base file name>_::
144 see description of '-u' parameter in setfont manual; taken from unimaps
145 directory; will be written as FONT_UNIMAP to _/etc/vconsole.conf_ in the
148 **locale.LANG=**_<locale>_::
149 taken from the environment; if no UNICODE is defined we set its value in
150 basis of LANG value (whether it ends with ".utf8" (or similar) or not); will
151 be written as LANG to _/etc/locale.conf_ in the initramfs; e.g.:
154 locale.LANG=pl_PL.utf8
157 **locale.LC_ALL=**_<locale>_::
158 taken from the environment; will be written as LC_ALL to _/etc/locale.conf_
164 disable LVM detection
166 **rd.lvm.vg=**_<volume group name>_::
167 only activate the volume groups with the given name. rd.lvm.vg can be
168 specified multiple times on the kernel command line.
170 **rd.lvm.lv=**_<logical volume name>_::
171 only activate the logical volumes with the given name. rd.lvm.lv can be
172 specified multiple times on the kernel command line.
175 remove any _/etc/lvm/lvm.conf_, which may exist in the initramfs
180 disable crypto LUKS detection
182 **rd.luks.uuid=**_<luks uuid>_::
183 only activate the LUKS partitions with the given UUID. Any "luks-" of the
184 LUKS UUID is removed before comparing to _<luks uuid>_.
185 The comparisons also matches, if _<luks uuid>_ is only the beginning of the
186 LUKS UUID, so you don't have to specify the full UUID.
187 This parameter can be specified multiple times.
189 **rd.luks.crypttab=0**::
190 do not check, if LUKS partition is in _/etc/crypttab_
192 crypto LUKS - key on removable device support
193 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
194 **rd.luks.key=**_<keypath>:<keydev>:<luksdev>_::
195 _keypath_ is a path to key file to look for. It's REQUIRED. When _keypath_ ends with '.gpg' it's considered to be key encrypted symmetrically with GPG. You will be prompted for password on boot. GPG support comes with 'crypt-gpg' module which needs to be added explicitly.
197 _keydev_ is a device on which key file resides. It might be kernel name of devices (should start with "/dev/"), UUID (prefixed with "UUID=") or label (prefix with "LABEL="). You don't have to specify full UUID. Just its beginning will suffice, even if its ambiguous. All matching devices will be probed. This parameter is recommended, but not required. If not present, all block devices will be probed, which may significantly increase boot time.
199 If _luksdev_ is given, the specified key will only be applied for that LUKS device. Possible values are the same as for _keydev_. Unless you have several LUKS devices, you don't have to specify this parameter. The simplest usage is:
202 rd.luks.key=/foo/bar.key
205 As you see, you can skip colons in such a case.
210 disable MD RAID detection
213 disable MD RAID for imsm/isw raids, use DM RAID instead
216 disable MD RAID for SNIA ddf raids, use DM RAID instead
219 ignore mdadm.conf included in initramfs
221 **rd.md.waitclean=1**::
222 wait for any resync, recovery, or reshape activity to finish before continuing
224 **rd.md.uuid=**_<md raid uuid>_::
225 only activate the raid sets with the given UUID. This parameter can be
226 specified multiple times.
231 disable DM RAID detection
233 **rd.dm.uuid=**_<dm raid uuid>_::
234 only activate the raid sets with the given UUID. This parameter can be
235 specified multiple times.
242 **boot=**_<boot device>_::
243 specify the device, where /boot is located. e.g.
247 boot=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
252 **rd.fips.skipkernel**::
253 skip checksum check of the kernel image. Useful, if the kernel image is not
254 in a separate boot partition.
258 **ip=**_{dhcp|on|any|dhcp6|auto6|ibft}_::
259 dhcp|on|any::: get ip from dhcp server from all interfaces. If root=dhcp, loop
260 sequentially through all interfaces (eth0, eth1, ...) and use the first with
261 a valid DHCP root-path.
263 auto6::: IPv6 autoconfiguration
267 ibft::: iBFT autoconfiguration
269 **ip=**_<interface>_:_{dhcp|on|any|dhcp6|auto6}_::
270 This parameter can be specified multiple times.
272 dhcp|on|any|dhcp6::: get ip from dhcp server on a specific interface
273 auto6::: do IPv6 autoconfiguration
275 **ip=**_<client-IP>_:_<server-IP>_:_<gateway-IP>_:_<netmask>_:_<client_hostname>_:_<interface>_:_{none|off}_::
276 explicit network configuration. If you want do define a IPv6 address, put it
277 in brackets (e.g. [2001:DB8::1]). This parameter can be specified multiple
280 **ifname=**_<interface>_:_<MAC>_::
281 Assign network device name <interface> (ie eth0) to the NIC with MAC <MAC>.
282 Note: If you use this option you _must_ specify an ifname= argument for all
283 interfaces used in ip= or fcoe= arguments. This parameter can be specified
286 **bootdev=**_<interface>_::
287 specify network interface to use routing and netroot information from.
288 Required if multiple ip= lines are used.
290 **nameserver=**__<IP>__ [**nameserver=**__<IP>__ ...]::
291 specify nameserver(s) to use
294 boolean, turn off biosdevname network interface renaming
297 boolean, bring up network even without netroot set
301 **root=**[_<server-ip>_:]_<root-dir>_[:_<nfs-options>_]::
302 mount nfs share from <server-ip>:/<root-dir>, if no server-ip is given, use
303 dhcp next_server. if server-ip is an IPv6 address it has to be put in
304 brackets, e.g. [2001:DB8::1]. NFS options can be appended with the prefix
305 ":" or "," and are seperated by ",".
307 **root=**nfs:[_<server-ip>_:]_<root-dir>_[:_<nfs-options>_], **root=**nfs4:[_<server-ip>_:]_<root-dir>_[:_<nfs-options>_], **root=**_{dhcp|dhcp6}_::
308 root=dhcp alone directs initrd to look at the DHCP root-path where NFS
309 options can be specified.
312 root-path=<server-ip>:<root-dir>[,<nfs-options>]
313 root-path=nfs:<server-ip>:<root-dir>[,<nfs-options>]
314 root-path=nfs4:<server-ip>:<root-dir>[,<nfs-options>]
317 **root=**_/dev/nfs_ nfsroot=[_<server-ip>_:]_<root-dir>_[:_<nfs-options>_]::
318 _Deprecated!_ kernel Documentation_/filesystems/nfsroot.txt_ defines this
319 method. This is supported by dracut, but not recommended.
321 **rd.nfs.domain=**_<NFSv4 domain name>_::
322 Set the NFSv4 domain name. Will overwrite the settings in _/etc/idmap.conf_.
326 **root=**iscsi:[_<username>_:_<password>_[:_<reverse>_:_<password>_]@][_<servername>_]:[_<protocol>_]:[_<port>_]:[_<LUN>_]:_<targetname>_::
327 protocol defaults to "6", LUN defaults to "0". If the "servername" field is
328 provided by BOOTP or DHCP, then that field is used in conjunction with other
329 associated fields to contact the boot server in the Boot stage. However, if
330 the "servername" field is not provided, then the "targetname" field is then
331 used in the Discovery Service stage in conjunction with other associated
333 link:$$http://tools.ietf.org/html/rfc4173#section-5$$[rfc4173].
337 root=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
340 If servername is an IPv6 address, it has to be put in brackets. e.g.:
343 root=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0
346 **root=**_???_ **netroot=**iscsi:[_<username>_:_<password>_[:_<reverse>_:_<password>_]@][_<servername>_]:[_<protocol>_]:[_<port>_]:[_<LUN>_]:_<targetname>_ ...::
347 multiple netroot options allow setting up multiple iscsi disks. e.g.:
351 netroot=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
352 netroot=iscsi:192.168.50.1::::iqn.2009-06.dracut:target1
355 If servername is an IPv6 address, it has to be put in brackets. e.g.:
358 netroot=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0
361 **root=**_???_ **rd.iscsi.initiator=**_<initiator>_ **rd.iscsi.target.name=**_<target name>_ **rd.iscsi.target.ip=**_<target ip>_ **rd.iscsi.target.port=**_<target port>_ **rd.iscsi.target.group=**_<target group>_ **rd.iscsi.username=**_<username>_ **rd.iscsi.password=**_<password>_ **rd.iscsi.in.username=**_<in username>_ **rd.iscsi.in.password=**_<in password>_::
362 manually specify all iscsistart parameter (see **+iscsistartĀ --help+**)
364 **root=**_???_ **netroot=**iscsi **rd.iscsi.firmware=1**::
365 will read the iscsi parameter from the BIOS firmware
369 **fcoe=**_<edd|interface|MAC>_:_{dcb|nodcb}_::
370 Try to connect to a FCoE SAN through the NIC specified by _<interface>_ or
371 _<MAC>_ or EDD settings. For the second argument, currently only nodcb is
372 supported. This parameter can be specified multiple times. Note: letters in
373 the MAC-address must be lowercase!
377 **root=**??? **netroot=**nbd:_<server>_:_<port>_[:_<fstype>_[:_<mountopts>_[:_<nbdopts>_]]]::
378 mount nbd share from <server>
380 **root=dhcp** with **dhcp** **root-path=**nbd:_<server>_:_<port>_[:_<fstype>_[:_<mountopts>_[:_<nbdopts>_]]]::
381 root=dhcp alone directs initrd to look at the DHCP root-path where NBD
382 options can be specified. This syntax is only usable in cases where you are
383 directly mounting the volume as the rootfs.
387 **rd.dasd_mod.dasd=**....::
388 same syntax as the kernel module parameter (s390 only)
390 **rd.dasd=**_<dasd_adaptor device bus ID>_[,readonly=_X_][,use_diag=_X_][,erplog=_X_]::
391 activate DASD device with the given adaptor device bus ID and setting the
392 sysfs attributes to the specified values. This parameter can be specified
397 **rd.zfcp=**_<zfcp adaptor device bus ID>_,_<WWPN>_,_<FCPLUN>_::
398 rd.zfcp can be specified multiple times on the kernel command line. e.g.:
401 rd.zfcp=0.0.4000,0x5005076300C213e9,0x5022000000000000
405 ignore zfcp.conf included in the initramfs
409 **rd.znet=**_<nettype>_,_<subchannels>_,_<options>_::
410 rd.znet can be specified multiple times on the kernel command line. e.g.:
413 rd.znet=qeth,0.0.0600,0.0.0601,0.0.0602,layer2=1,portname=foo
414 rd.znet=ctc,0.0.0600,0.0.0601,0.0.0602,protocol=bar
419 **plymouth.enable=0**::
420 disable the plymouth bootsplash completly.
423 disable the plymouth bootsplash only for the initramfs.
427 **masterkey=**_<kernel master key path name>_::
428 Set the path name of the kernel master key. e.g.:
431 masterkey=/etc/keys/kmk-trusted.blob
434 **masterkeytype=**_<kernel master key type>_::
435 Set the type of the kernel master key. e.g.:
438 masterkeytype=trusted
441 **evmkey=**_<EVM key path name>_::
442 Set the path name of the EVM key. e.g.:
445 evmkey=/etc/keys/evm-trusted.blob
448 **ecryptfskey=**_<eCryptfs key path name>_::
449 Set the path name of the eCryptfs key. e.g.:
452 ecryptfskey=/etc/keys/ecryptfs-trusted.blob
455 Deprecated, renamed Options
456 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
457 Here is a list of options, which were used in dracut prior to version 008, and their new replacement.
463 rd_DASD_MOD:: rd.dasd_mod.dasd
467 rdinitdebug rdnetdebug:: rd.debug
471 rd_DM_UUID:: rd.dm.uuid
473 rdblacklist:: rd.driver.blacklist
475 rdinsmodpost:: rd.driver.post
477 rdloaddriver:: rd.driver.pre
479 rd_NO_FSTAB:: rd.fstab=0
483 check:: rd.live.check
485 rdlivedebug:: rd.live.debug
487 live_dir:: rd.live.dir
489 liveimg:: rd.live.image
491 overlay:: rd.live.overlay
493 readonly_overlay:: rd.live.overlay.readonly
495 reset_overlay:: rd.live.overlay.reset
497 live_ram:: rd.live.ram
499 rd_NO_CRYPTTAB:: rd.luks.crypttab=0
501 rd_LUKS_KEYDEV_UUID:: rd.luks.keydev.uuid
503 rd_LUKS_KEYPATH:: rd.luks.keypath
505 rd_NO_LUKS:: rd.luks=0
507 rd_LUKS_UUID:: rd.luks.uuid
509 rd_NO_LVMCONF:: rd.lvm.conf
511 rd_LVM_LV:: rd.lvm.lv
515 rd_LVM_SNAPSHOT:: rd.lvm.snapshot
517 rd_LVM_SNAPSIZE:: rd.lvm.snapsize
519 rd_LVM_VG:: rd.lvm.vg
521 rd_NO_MDADMCONF:: rd.md.conf=0
523 rd_NO_MDIMSM:: rd.md.imsm=0
527 rd_MD_UUID:: rd.md.uuid
529 rd_NFS_DOMAIN:: rd.nfs.domain
531 iscsi_initiator:: rd.iscsi.initiator
533 iscsi_target_name:: rd.iscsi.target.name
535 iscsi_target_ip:: rd.iscsi.target.ip
537 iscsi_target_port:: rd.iscsi.target.port
539 iscsi_target_group:: rd.iscsi.target.group
541 iscsi_username:: rd.iscsi.username
543 iscsi_password:: rd.iscsi.password
545 iscsi_in_username:: rd.iscsi.in.username
547 iscsi_in_password:: rd.iscsi.in.password
549 iscsi_firmware:: rd.iscsi.firmware=0
551 rd_NO_PLYMOUTH:: rd.plymouth=0
557 rd_NO_SPLASH:: rd.splash
559 rdudevdebug:: rd.udev.debug
561 rdudevinfo:: rd.udev.info
563 rd_NO_ZFCPCONF:: rd.zfcp.conf=0
569 KEYMAP:: vconsole.keymap
571 KEYTABLE:: vconsole.keymap
573 SYSFONT:: vconsole.font
575 CONTRANS:: vconsole.font.map
577 UNIMAP:: vconsole.font.unimap
579 UNICODE:: vconsole.unicode
581 EXT_KEYMAP:: vconsole.keymap.ext
583 Configuration in the Initramfs
584 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
586 Any files found in _/etc/conf.d/_ will be sourced in the initramfs to
587 set initial values. Command line options will override these values
588 set in the configuration files.
591 Can contain additional command line options.
593 _/etc/cmdline.d/*.conf_::
594 Can contain additional command line options.
599 Project Leader and Developer
603 *dracut*(8) *dracut.conf*(5)