DRACUT.CMDLINE(7) dracut DRACUT.CMDLINE(7)NAME
dracut.cmdline - dracut kernel command line options
DESCRIPTION
The root device used by the kernel is specified in the boot
configuration file on the kernel command line, as always.
The traditional root=/dev/sda1 style device specification is allowed,
but not encouraged. The root device should better be identified by
LABEL or UUID. If a label is used, as in root=LABEL=<label_of_root> the
initramfs will search all available devices for a filesystem with the
appropriate label, and mount that device as the root filesystem.
root=UUID=<uuidnumber> will mount the partition with that UUID as the
root filesystem.
In the following all kernel command line parameters, which are
processed by dracut, are described.
"rd.*" parameters mentioned without "=" are boolean parameters. They
can be turned on/off by setting them to {0|1}. If the assignment with
"=" is missing "=1" is implied. For example rd.info can be turned off
with rd.info=0 or turned on with rd.info=1 or rd.info. The last value
in the kernel command line is the value, which is honored.
Standard
init=<path to real init>
specify the path to the init programm to be started after the
initramfs has finished
root=<path to blockdevice>
specify the block device to use as the root filesystem.
E.g.:
root=/dev/sda1
root=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
root=/dev/disk/by-label/Root
root=LABEL=Root
root=/dev/disk/by-uuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
root=UUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
rootfstype=<filesystem type>
"auto" if not specified, e.g.:
rootfstype=ext3
rootflags=<mount options>
specify additional mount options for the root filesystem. If not
set, /etc/fstab of the real root will be parsed for special mount
options and mounted accordingly.
rd.fstab=0
do not honor special mount options for the root filesystem found in
/etc/fstab of the real root.
resume=<path to resume partition>
+ E.g.:
+
resume=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
resume=/dev/disk/by-uuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
resume=UUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
Misc
rd.driver.blacklist=<drivername>[,<drivername>,...]
do not load kernel module <drivername>. This parameter can be
specified multiple times.
rd.driver.pre=<drivername>[,<drivername>,...]
force loading kernel module <drivername>. This parameter can be
specified multiple times.
rd.driver.post=<drivername>[,<drivername>,...]
force loading kernel module <drivername> after all automatic
loading modules have been loaded. This parameter can be specified
multiple times.
Debug
rd.info
print informational output though "quiet" is set
rd.shell
allow dropping to a shell, if root mounting fails
rd.debug
set -x for the dracut shell and logs to dmesg, console and
/run/initramfs/init.log
rd.break
drop to a shell at the end
rd.break={cmdline|pre-udev|pre-trigger|initqueue|pre-mount|mount|pre-pivot|pre-pivot-cleanup}
drop to a shell on defined breakpoint
rd.udev.info
set udev to loglevel info
rd.udev.debug
set udev to loglevel debug
I18N
vconsole.keymap=<keymap base file name>
keyboard translation table loaded by loadkeys; taken from keymaps
directory; will be written as KEYMAP to /etc/vconsole.conf in the
initramfs, e.g.:
vconsole.keymap=de-latin1-nodeadkeys
vconsole.keymap.ext=<list of keymap base file names>
list of extra keymaps to bo loaded (sep. by space); will be written
as EXT_KEYMAP to /etc/vconsole.conf in the initramfs
vconsole.unicode[={0|1}]
boolean, indicating UTF-8 mode; will be written as UNICODE to
/etc/vconsole.conf in the initramfs
vconsole.font=<font base file name>
console font; taken from consolefonts directory; will be written as
FONT to /etc/vconsole.conf in the initramfs; e.g.:
vconsole.font=LatArCyrHeb-16
vconsole.font.map=<console map base file name>
see description of -m parameter in setfont manual; taken from
consoletrans directory; will be written as FONT_MAP to
/etc/vconsole.conf in the initramfs
vconsole.font.unimap=<unicode table base file name>
see description of -u parameter in setfont manual; taken from
unimaps directory; will be written as FONT_UNIMAP to
/etc/vconsole.conf in the initramfs
locale.LANG=<locale>
taken from the environment; if no UNICODE is defined we set its
value in basis of LANG value (whether it ends with ".utf8" (or
similar) or not); will be written as LANG to /etc/locale.conf in
the initramfs; e.g.:
locale.LANG=pl_PL.utf8
locale.LC_ALL=<locale>
taken from the environment; will be written as LC_ALL to
/etc/locale.conf in the initramfs
LVM
rd.lvm=0
disable LVM detection
rd.lvm.vg=<volume group name>
only activate the volume groups with the given name. rd.lvm.vg can
be specified multiple times on the kernel command line.
rd.lvm.lv=<logical volume name>
only activate the logical volumes with the given name. rd.lvm.lv
can be specified multiple times on the kernel command line.
rd.lvm.conf=0
remove any /etc/lvm/lvm.conf, which may exist in the initramfs
crypto LUKS
rd.luks=0
disable crypto LUKS detection
rd.luks.uuid=<luks uuid>
only activate the LUKS partitions with the given UUID. Any "luks-"
of the LUKS UUID is removed before comparing to <luks uuid>. The
comparisons also matches, if <luks uuid> is only the beginning of
the LUKS UUID, so you don’t have to specify the full UUID. This
parameter can be specified multiple times.
rd.luks.allow-discards=<luks uuid>
Allow using of discards (TRIM) requests for LUKS partitions with
the given UUID. Any "luks-" of the LUKS UUID is removed before
comparing to <luks uuid>. The comparisons also matches, if <luks
uuid> is only the beginning of the LUKS UUID, so you don’t have to
specify the full UUID. This parameter can be specified multiple
times.
**rd.luks.allow-discards
Allow using of discards (TRIM) requests on all LUKS partitions.
rd.luks.crypttab=0
do not check, if LUKS partition is in /etc/crypttab
crypto LUKS - key on removable device support
rd.luks.key=<keypath>:<keydev>:<luksdev>
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.
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.
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:
rd.luks.key=/foo/bar.key
As you see, you can skip colons in such a case.
MD RAID
rd.md=0
disable MD RAID detection
rd.md.imsm=0
disable MD RAID for imsm/isw raids, use DM RAID instead
rd.md.ddf=0
disable MD RAID for SNIA ddf raids, use DM RAID instead
rd.md.conf=0
ignore mdadm.conf included in initramfs
rd.md.waitclean=1
wait for any resync, recovery, or reshape activity to finish before
continuing
rd.md.uuid=<md raid uuid>
only activate the raid sets with the given UUID. This parameter can
be specified multiple times.
DM RAID
rd.dm=0
disable DM RAID detection
rd.dm.uuid=<dm raid uuid>
only activate the raid sets with the given UUID. This parameter can
be specified multiple times.
FIPS
rd.fips
enable FIPS
boot=<boot device>
specify the device, where /boot is located. e.g.
boot=/dev/sda1
boot=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
boot=UUID=<uuid>
boot=LABEL=<label>
rd.fips.skipkernel
skip checksum check of the kernel image. Useful, if the kernel
image is not in a separate boot partition.
Network
ip={dhcp|on|any|dhcp6|auto6|ibft}
dhcp|on|any
get ip from dhcp server from all interfaces. If root=dhcp, loop
sequentially through all interfaces (eth0, eth1, ...) and use
the first with a valid DHCP root-path.
auto6
IPv6 autoconfiguration
dhcp6
IPv6 DHCP
ibft
iBFT autoconfiguration
ip=<interface>:{dhcp|on|any|dhcp6|auto6}[:[<mtu>][:<macaddr>]]
This parameter can be specified multiple times.
dhcp|on|any|dhcp6
get ip from dhcp server on a specific interface
auto6
do IPv6 autoconfiguration
<macaddr>
optionally set <macaddr> on the <interface>
ip=<client-IP>:<server-IP>:<gateway-IP>:<netmask>:<client_hostname>:<interface>:{none|off|dhcp|on|any|dhcp6|auto6|ibft}[:[<mtu>][:<macaddr>]]
explicit network configuration. If you want do define a IPv6
address, put it in brackets (e.g. [2001:DB8::1]). This parameter
can be specified multiple times.
<macaddr>
optionally set <macaddr> on the <interface>
ifname=<interface>:<MAC>
Assign network device name <interface> (ie eth0) to the NIC with
MAC <MAC>. Note: If you use this option you must specify an ifname=
argument for all interfaces used in ip= or fcoe= arguments. This
parameter can be specified multiple times.
bootdev=<interface>
specify network interface to use routing and netroot information
from. Required if multiple ip= lines are used.
nameserver=<IP> [nameserver=<IP> ...]
specify nameserver(s) to use
biosdevname=0
boolean, turn off biosdevname network interface renaming
rd.neednet=1
boolean, bring up network even without netroot set
NFS
root=<root-dir>[:<nfs-options>]
mount nfs share from <server-ip>:/<root-dir>, if no server-ip is
given, use dhcp next_server. if server-ip is an IPv6 address it has
to be put in brackets, e.g. [2001:DB8::1]. NFS options can be
appended with the prefix ":" or "," and are seperated by ",".
root=nfs:<root-dir>[:<nfs-options>],
root=nfs4:<root-dir>[:<nfs-options>], root={dhcp|dhcp6}
root=dhcp alone directs initrd to look at the DHCP root-path where
NFS options can be specified.
root-path=<server-ip>:<root-dir>[,<nfs-options>]
root-path=nfs:<server-ip>:<root-dir>[,<nfs-options>]
root-path=nfs4:<server-ip>:<root-dir>[,<nfs-options>]
root=/dev/nfs nfsroot=<root-dir>[:<nfs-options>]
Deprecated! kernel Documentation_/filesystems/nfsroot.txt_ defines
this method. This is supported by dracut, but not recommended.
rd.nfs.domain=<NFSv4 domain name>
Set the NFSv4 domain name. Will overwrite the settings in
/etc/idmap.conf.
iSCSI
root=iscsi:[<username>:<password>[:<reverse>:<password>]@][<servername>]:[<protocol>]:[<port>][:[<iscsi_iface_name>]:[<netdev_name>]]:[<LUN>]:<targetname>
protocol defaults to "6", LUN defaults to "0". If the "servername"
field is provided by BOOTP or DHCP, then that field is used in
conjunction with other associated fields to contact the boot server
in the Boot stage. However, if the "servername" field is not
provided, then the "targetname" field is then used in the Discovery
Service stage in conjunction with other associated fields. See
rfc4173[1]. e.g.:
root=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
If servername is an IPv6 address, it has to be put in brackets.
e.g.:
root=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0
root=???
netroot=iscsi:[<username>:<password>[:<reverse>:<password>]@][<servername>]:[<protocol>]:[<port>][:[<iscsi_iface_name>]:[<netdev_name>]]:[<LUN>]:<targetname>
...
multiple netroot options allow setting up multiple iscsi disks.
e.g.:
root=UUID=12424547
netroot=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
netroot=iscsi:192.168.50.1::::iqn.2009-06.dracut:target1
If servername is an IPv6 address, it has to be put in brackets.
e.g.:
netroot=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0
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>
manually specify all iscsistart parameter (see iscsistart --help)
root=??? netroot=iscsi rd.iscsi.firmware=1
will read the iscsi parameter from the BIOS firmware
rd.iscsi.param=<param>
<param> will be passed as "--param <param>" to iscsistart. This
parameter can be specified multiple times. e.g.:
"netroot=iscsi iscsi_firmware rd.iscsi.param=node.session.timeo.replacement_timeout=30"
will result in
iscsistart -b --param node.session.timeo.replacement_timeout=30
FCoE
fcoe=<edd|interface|MAC>:{dcb|nodcb}
Try to connect to a FCoE SAN through the NIC specified by
<interface> or <MAC> or EDD settings. For the second argument,
currently only nodcb is supported. This parameter can be specified
multiple times. Note: letters in the MAC-address must be lowercase!
NBD
root=???
netroot=nbd:<server>:<port>[:<fstype>[:<mountopts>[:<nbdopts>]]]
mount nbd share from <server>
root=dhcp with dhcp
root-path=nbd:<server>:<port>[:<fstype>[:<mountopts>[:<nbdopts>]]]
root=dhcp alone directs initrd to look at the DHCP root-path where
NBD options can be specified. This syntax is only usable in cases
where you are directly mounting the volume as the rootfs.
DASD
rd.dasd=....
same syntax as the kernel module parameter (s390 only)
ZFCP
rd.zfcp=<zfcp adaptor device bus ID>,<WWPN>,<FCPLUN>
rd.zfcp can be specified multiple times on the kernel command line.
e.g.:
rd.zfcp=0.0.4000,0x5005076300C213e9,0x5022000000000000
rd.zfcp.conf=0
ignore zfcp.conf included in the initramfs
ZNET
rd.znet=<nettype>,<subchannels>,<options>
rd.znet can be specified multiple times on the kernel command line.
e.g.:
rd.znet=qeth,0.0.0600,0.0.0601,0.0.0602,layer2=1,portname=foo
rd.znet=ctc,0.0.0600,0.0.0601,0.0.0602,protocol=bar
Plymouth Boot Splash
plymouth.enable=0
disable the plymouth bootsplash completly.
rd.plymouth=0
disable the plymouth bootsplash only for the initramfs.
Kernel keys
masterkey=<kernel master key path name>
Set the path name of the kernel master key. e.g.:
masterkey=/etc/keys/kmk-trusted.blob
masterkeytype=<kernel master key type>
Set the type of the kernel master key. e.g.:
masterkeytype=trusted
evmkey=<EVM key path name>
Set the path name of the EVM key. e.g.:
evmkey=/etc/keys/evm-trusted.blob
ecryptfskey=<eCryptfs key path name>
Set the path name of the eCryptfs key. e.g.:
ecryptfskey=/etc/keys/ecryptfs-trusted.blob
Deprecated, renamed Options
Here is a list of options, which were used in dracut prior to version
008, and their new replacement.
rdbreak
rd.break
rd_CCW
rd.ccw
rd_DASD_MOD
rd.dasd
rd_DASD
rd.dasd
rdinitdebug rdnetdebug
rd.debug
rd_NO_DM
rd.dm=0
rd_DM_UUID
rd.dm.uuid
rdblacklist
rd.driver.blacklist
rdinsmodpost
rd.driver.post
rdloaddriver
rd.driver.pre
rd_NO_FSTAB
rd.fstab=0
rdinfo
rd.info
check
rd.live.check
rdlivedebug
rd.live.debug
live_dir
rd.live.dir
liveimg
rd.live.image
overlay
rd.live.overlay
readonly_overlay
rd.live.overlay.readonly
reset_overlay
rd.live.overlay.reset
live_ram
rd.live.ram
rd_NO_CRYPTTAB
rd.luks.crypttab=0
rd_LUKS_KEYDEV_UUID
rd.luks.keydev.uuid
rd_LUKS_KEYPATH
rd.luks.keypath
rd_NO_LUKS
rd.luks=0
rd_LUKS_UUID
rd.luks.uuid
rd_NO_LVMCONF
rd.lvm.conf
rd_LVM_LV
rd.lvm.lv
rd_NO_LVM
rd.lvm=0
rd_LVM_SNAPSHOT
rd.lvm.snapshot
rd_LVM_SNAPSIZE
rd.lvm.snapsize
rd_LVM_VG
rd.lvm.vg
rd_NO_MDADMCONF
rd.md.conf=0
rd_NO_MDIMSM
rd.md.imsm=0
rd_NO_MD
rd.md=0
rd_MD_UUID
rd.md.uuid
rd_NFS_DOMAIN
rd.nfs.domain
iscsi_initiator
rd.iscsi.initiator
iscsi_target_name
rd.iscsi.target.name
iscsi_target_ip
rd.iscsi.target.ip
iscsi_target_port
rd.iscsi.target.port
iscsi_target_group
rd.iscsi.target.group
iscsi_username
rd.iscsi.username
iscsi_password
rd.iscsi.password
iscsi_in_username
rd.iscsi.in.username
iscsi_in_password
rd.iscsi.in.password
iscsi_firmware
rd.iscsi.firmware=0
rd_NO_PLYMOUTH
rd.plymouth=0
rd_retry
rd.retry
rdshell
rd.shell
rd_NO_SPLASH
rd.splash
rdudevdebug
rd.udev.debug
rdudevinfo
rd.udev.info
rd_NO_ZFCPCONF
rd.zfcp.conf=0
rd_ZFCP
rd.zfcp
rd_ZNET
rd.znet
KEYMAP
vconsole.keymap
KEYTABLE
vconsole.keymap
SYSFONT
vconsole.font
CONTRANS
vconsole.font.map
UNIMAP
vconsole.font.unimap
UNICODE
vconsole.unicode
EXT_KEYMAP
vconsole.keymap.ext
Configuration in the Initramfs
/etc/conf.d/
Any files found in /etc/conf.d/ will be sourced in the initramfs to
set initial values. Command line options will override these values
set in the configuration files.
/etc/cmdline
Can contain additional command line options.
/etc/cmdline.d/*.conf
Can contain additional command line options.
AUTHOR
Harald Hoyer
Project Leader and Developer
SEE ALSOdracut(8)dracut.conf(5)NOTES
1. rfc4173
http://tools.ietf.org/html/rfc4173#section-5
dracut 09/27/2012 DRACUT.CMDLINE(7)
