dracut Developer Harald Hoyer harald@redhat.com dracut.kernel 7 dracut.kernel dracut kernel command line options The root filesystem used by the kernel is specified in the boot configuration file, as always. The traditional root=/dev/hda1 style device specification is allowed. If a label is used, as in root=LABEL=rootPart the initramfs will search all available devices for an ext2 or ext3 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. 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. rd.fstab=0 do not honor special mount options for the root filesystem found in /etc/fstab of the real root. 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. 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 /init.log rd.break drop to a shell at the end rd.break={cmdline|pre-udev|pre-trigger|initqueue|pre-mount|mount|pre-pivot} drop to a shell on defined breakpoint rd.udev.info set udev to loglevel info rd.udev.debug set udev to loglevel debug rd.timestamp export RDTIMESTAMP environment variable to init, which is set to the uptime of the dracut start. voonsole.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=<1|0> 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 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 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.crypttab=0 do not check, if LUKS partition is in /etc/crypttab rd.luks.key=<keypath>:<keydev>:<luksdev> keypath is a path to key file to look for. It's REQUIRED. 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 case. rd.md=0 disable MD RAID detection rd.md.imsm=0 disable MD RAID for imsm/isw raids, use DM RAID instead rd.md.conf=0 ignore mdadm.conf included in initramfs rd.md.uuid=<md raid uuid> only activate the raid sets with the given UUID. This parameter can be specified multiple times. 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. 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>:<client_hostname>:<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 letters in the MAC-address must be lowercase! 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|1} turn on/off biosdevname network interface renaming 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. root=iscsi:<username>:<password>:<reverse>:<password>@ <servername> : <protocol> : <port> : <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 http://tools.ietf.org/html/rfc4173. 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> : <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=??? rd.iscsi.firmware=1 will read the iscsi parameter from the BIOS firmware 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! 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. rd.dasd_mod.dasd=.... same syntax as the kernel module parameter (s390 only) rd.dasd=<dasd_adaptor device bus ID>,readonly=X,use_diag=X,erplog=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. 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 ignore zfcp.conf included in the initramfs 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 rd.plymouth=0 disable plymouth. This will not work with encrypted partitions. 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 rdcopystate rd.copystate rd_DASD_MOD rd.dasd_mod.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 /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. dracut 8 dracut.conf 5