Options¶

-f, --force

overwrite existing initramfs file.

-m, --modules LIST

specify a space-separated list of dracut modules to call when building the initramfs. Modules are located in /usr/share/dracut/modules.d.

-o, --omit LIST

omit a space-separated list of dracut modules.

-a, --add LIST

add a space-separated list of dracut modules.

-d, --drivers LIST

specify a space-separated list of kernel modules to exclusively include in the initramfs. The kernel modules have to be specified without the ".ko" suffix.

--add-drivers LIST

specify a space-separated list of kernel modules to add to the initramfs. The kernel modules have to be specified without the ".ko" suffix.

--omit-drivers LIST

specify a space-separated list of kernel modules to omit from the initramfs. The kernel modules have to be specified without the ".ko" suffix. Regular expressions are also allowed like ".*/fs/ocfs/.*".

If [LIST] has multiple arguments, then you have to put these in quotes.

example: # dracut --omit "module1 module2" ...

--filesystems LIST

specify a space-separated list of kernel filesystem modules to exclusively include in the generic initramfs.

-k, --kmoddir {DIR}

specify the directory, where to look for kernel modules

--fwdir {DIR}

specify additional directory, where to look for firmwares

--kernel-only

only install kernel drivers and firmware files

--no-kernel

do not install kernel drivers and firmware files

--mdadmconf

include local /etc/mdadm.conf

--nomdadmconf

do not include local /etc/mdadm.conf

--strip

strip binaries in the initramfs (default)

--nostrip

do not strip binaries in the initramfs

-h, --help

display help text and exit.

--debug

output debug information of the build process

-v, --verbose

verbose output during the build process

-c, --conf FILE

specify configuration file to use. Default: /etc/dracut.conf

--confdir DIR

specify configuration directory to use. Default: /etc/dracut.conf.d

-l, --local

local mode. Use modules from the current working directory instead of the system-wide installed in /usr/share/dracut/modules.d. Useful when running dracut from a git checkout.

-H, --hostonly

Host-Only mode: Install only what is needed for booting the local host instead of a generic host.

-i, --include SOURCE TARGET

include the files in the SOURCE directory into the target directory in the final initramfs.

-I, --install LIST

install the space separated list of files into the initramfs.

Standard¶

init=<path to real init>

root=<path to blockdevice>

specify blockdevice to use as root filesystem.
e.g.
root=/dev/sda1
root=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1

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.

rootfallback=<path to blockdevice>

specify the block device to use as the root filesystem, if the normal root cannot be found. This can only be a simple block device with a simple file system, for which the filesystem driver is either compiled in, or added manually to the initramfs. This parameter can be specified multiple times.

rd_NO_FSTAB

do not honor special mount options for the root filesystem found in /etc/fstab of the real root.

Misc¶

hostname=<hostname>

set the initial hostname

rdblacklist=<drivername>

do not load kernel module <drivername> This parameter can be specified multiple times.

rdloaddriver=<drivername>

force loading kernel module <drivername> This parameter can be specified multiple times.

rd_retry=<seconds>

wait <seconds> until dracut tries to force assemble LVM or RAID volumes. If the root device is not found within <seconds>*2 then dracut fails and either drops to a shell, if rdshell is on the kernel command line, or exits with 1, which normally causes a kernel panic.

Default: rd_retry=40

Debug¶

rdinfo

print informational output though "quiet" is set

rdshell

allow dropping to a shell, if root mounting fails

rdinitdebug

set -x for the dracut shell and logs to dmesg, console and /init.log

rdbreak

drop to a shell at the end

rdbreak={cmdline|pre-udev|pre-trigger|initqueue|pre-mount|mount|pre-pivot}

drop to a shell on defined breakpoint

rdudevinfo

set udev to loglevel info

rdudevdebug

set udev to loglevel debug

I18N¶

e.g.
LANG=en_US.UTF-8
SYSFONT=latarcyrheb-sun16
KEYTABLE=de-latin1-nodeadkeys

KEYBOARDTYPE=sun|pc

will be written to /etc/sysconfig/keyboard in the initramfs

KEYTABLE=<keytable filename>

will be written to /etc/sysconfig/keyboard in the initramfs

SYSFONT=Console font

will be written to /etc/sysconfig/i18n in the initramfs

SYSFONTACM=Unicode font map

will be written to /etc/sysconfig/i18n in the initramfs

UNIMAP=Unicode font map

will be written to /etc/sysconfig/i18n in the initramfs

LANG=<locale>

will be written to /etc/sysconfig/i18n in the initramfs

LVM¶

rd_NO_LVM

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_NO_LVMCONF

remove any /etc/lvm/lvm.conf, which may exist in the initramfs

crypto LUKS¶

rd_NO_LUKS

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_NO_CRYPTTAB

do not check, if LUKS partition is in /etc/crypttab

MD¶

rd_NO_MD

disable MD RAID detection

rd_NO_MDIMSM

no MD RAID for imsm/isw raids, use dmraid instead

rd_NO_MDADMCONF

ignore mdadm.conf included in initramfs

rd_MD_UUID=<md uuid>

only activate the raid sets with the given UUID. This parameter can be specified multiple times.

DMRAID¶

rd_NO_DM

disable DM RAID detection

rd_DM_UUID=<dmraid uuid>

only activate the raid sets with the given UUID. This parameter can be specified multiple times.

MULTIPATH¶

rd_NO_MULTIPATH

disable multipath in the initramfs

FIPS¶

fips=1

enable FIPS

boot=<bootdevice>

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>

If the root device is encrypted, the /boot partition must reside on a seperate partition and has to be specified.

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}

dhcp|on|any|dhcp6: get ip from dhcp server on a specific interface auto6: do IPv6 autoconfiguration This parameter can be specified multiple times.

ip=<client-IP>:[<server-id>]:<gateway-IP>:<netmask>:<clienthostname>:<interface>:{none|off}

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.

ifname=<interface>:<MAC>

Assign network device name <interface> (ie eth0) to the NIC with MAC <MAC>. Note that 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

vlan=<vlanname>:<phydevice>

Setup vlan device named <vlanname> on <phydeivce>.
We support the four styles of vlan names: VLAN_PLUS_VID (vlan0005), VLAN_PLUS_VID_NO_PAD (vlan5), DEV_PLUS_VID (eth0.0005), DEV_PLUS_VID_NO_PAD (eth0.5) This parameter can be specified multiple times.

bridge=<bridgename>:<ethnames>

Setup bridge <bridgename> with <ethnames>. <ethnames> is a comma-separated list of physical (ethernet) interfaces. Bridge without parameters assumes bridge=br0:eth0

bond=<bondname>[:<bondslaves>:[:<options>]]

Setup bonding device <bondname> on top of <bondslaves>. <bondslaves> is a comma-separated list of physical (ethernet) interfaces. <options> is a comma-separated list on bonding options (modinfo bonding for details) in format compatible with initscripts. If <options> includes multi-valued arp_ip_target option, then its values should be separated by semicolon. Bond without parameters assumes bond=bond0:eth0,eth1:mode=balance-rr

biosdevname={0|1]}

turn off/on biosdevname network interface renaming

NFS¶

root=[<server-ip>:]<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:[<server-ip>:]<root-dir>[:<nfs-options>]

root=nfs4:[<server-ip>:]<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=[<server-ip>:]<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 (Section 7). 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.

http://tools.ietf.org/html/rfc4173

root=iscsi:[username:password[:reverse:password]@][<servername>]:[<protocol>]:[<port>][:[<iscsi_iface_name>]:[<netdev_name>]]:[<LUN>]:<targetname>

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=??? iscsi_initiator=<initiator> iscsi_target_name=<target name> iscsi_target_ip=<target ip> iscsi_target_port=<target port> iscsi_target_group=<target group> iscsi_username=<username> iscsi_password=<password> iscsi_in_username=<in username> iscsi_in_password=<in password>

manually specify all iscsistart parameter (see iscsistart --help)

root=??? netroot=iscsi iscsi_firmware

will read the iscsi parameter from the BIOS firmware

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 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. This parameter can be specified multiple times.

NBD¶

root=nbd:<server>:<port>[:<fstype>][:<mountopts>]

mount nbd share from <server>

root=dhcp

with dhcp root-path=nbd:<server>:<port>[:<fstype>][:<mountopts>] 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_MOD=....

same syntax as the kernel module parameter (s390 only)

rd_DASD=<dasd adaptor device bus ID>[,readonly=X][,use_diag=X][,erplog=X][,failfast=X]

activate DASD device with the given adaptor device bus ID and setting the sysfs attributes to the specified values This parameter can be specified multiple times.

ZFCP¶

rd_ZFCP=<zfcp adaptor device bus ID>,<WWPN>,<FCPLUN>

rd_ZFCP can be specified multiple times on the kernel command line.

example: rd_ZFCP=0.0.4000,0x5005076300C213e9,0x5022000000000000

rd_NO_ZFCPCONF

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. Examples:
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¶

rd_NO_PLYMOUTH

do not start plymouth. This will not work with encrypted partitions.

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.