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_NO_FSTAB do not honor special mount options for the root filesystem found in /etc/fstab of the real root. 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. 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 rd.timestamp export RDTIMESTAMP environment variable to init, which is set to the uptime of the dracut start. KEYMAP= <keymap base file name> keyboard translation table loaded by loadkeys; taken from keymaps directory; will be written to /etc/sysconfig/keyboard in the initramfs, e.g.: KEYMAP=de-latin1-nodeadkeys EXT_KEYMAPS= <list of keymap base file names> list of extra keymaps to bo loaded (sep. by space); will be written to /etc/sysconfig/keyboard in the initramfs UNICODE= <1|0> boolean, indicating UTF-8 mode; will be written to /etc/sysconfig/i18n in the initramfs SYSFONT= <font base file name> console font; taken from consolefonts directory; will be written to /etc/sysconfig/i18n in the initramfs; e.g.: SYSFONT=LatArCyrHeb-16 CONTRANS= <console map base file name> see description of '-m' parameter in setfont manual; taken from consoletrans directory; will be written to /etc/sysconfig/i18n in the initramfs UNIMAP= <unicode table base file name> see description of '-u' parameter in setfont manual; taken from unimaps directory; will be written to /etc/sysconfig/i18n in the initramfs 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 to /etc/sysconfig/i18n in the initramfs; e.g.: LANG=pl_PL.utf8 LC_ALL= <locale> taken from the environment; will be written to /etc/sysconfig/i18n in the initramfs 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 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 works only when plymouth module is not included rd_LUKS_KEYPATH= <path to keyfile> path to keyfile inside remove device filesystem rd_LUKS_KEYDEV_UUID= <rem. device uuid> UUID of removalbe device storing keyfile; UUID doesn't have to be exact just like for rd_LUKS_UUID 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. 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. ip= {dhcp|on|any|dhcp6|auto6} 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 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 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=??? 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=??? iscsi_firmware will read the iscsi parameter from the BIOS firmware netroot=fcoe:<interface|MAC>:{dcb|nodcb} Try to connect to a FCoE SAN through the NIC specified by <interface> or <MAC>, for the second argument, currently only nodcb is supported. 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=.... 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_NO_ZFCPCONF 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_NO_PLYMOUTH do not start plymouth. This will not work with encrypted partitions. /conf/conf.d/ Any files found in /conf/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