dracut/dracut.kernel.7.xml
Harald Hoyer 647bef8ca6 base/init: set RDTIMESTAMP
set $RDTIMESTAMP for init, if rd.timestamp is specified on the
kernel command line, so that systemd can print out:

"systemd: Boot finished after 15s = 3s (kernel) + 2s (initrd) + 10s
(userspace)"
2010-09-20 14:58:25 +02:00

746 lines
30 KiB
XML

<?xml version='1.0' encoding='UTF-8'?>
<!-- This document was created with Syntext Serna Free. --><!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.3/docbookx.dtd" []>
<refentry>
<refentryinfo>
<title>dracut.kernel</title>
<productname>dracut</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Harald</firstname>
<surname>Hoyer</surname>
<email>harald@redhat.com</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>dracut.kernel</refentrytitle>
<manvolnum>7</manvolnum>
<refmiscinfo class="version"/>
</refmeta>
<refnamediv>
<refname>dracut.kernel</refname>
<refpurpose>dracut kernel command line options</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<para>The root filesystem used by the kernel is specified in the boot configuration
file, as always. The traditional <emphasis remap="B">root=/dev/hda1</emphasis> style device
specification is allowed. If a label is used, as in <emphasis remap="B">root=LABEL=rootPart</emphasis>
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.
<emphasis remap="B">root=UUID=uuidnumber</emphasis> will mount the partition with that UUID as the
root filesystem.</para>
<refsect2>
<title>Standard</title>
<variablelist>
<varlistentry>
<term>
<envar>init=<replaceable>&lt;path to real init&gt;</replaceable></envar>
</term>
<listitem>
<para> </para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>root=<replaceable>&lt;path to blockdevice&gt;</replaceable></envar>
</term>
<listitem>
<para>specify blockdevice to use as root filesystem.
e.g.: <programlisting>root=/dev/sda1
root=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1 </programlisting></para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rootfstype=<replaceable>&lt;filesystem type&gt;</replaceable></envar>
</term>
<listitem>
<para>&quot;auto&quot; if not specified, e.g.: <programlisting>rootfstype=ext3</programlisting></para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rootflags=<replaceable>&lt;mount options&gt;</replaceable></envar>
</term>
<listitem>
<para>specify additional mount options for the root filesystem. If not set, <filename>/etc/fstab</filename>
of the real root will be parsed for special mount options and mounted
accordingly.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_NO_FSTAB</envar>
</term>
<listitem>
<para>do not honor special mount options for the root filesystem found in
<filename>/etc/fstab</filename> of the real root.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>Misc</title>
<variablelist>
<varlistentry>
<term>
<envar>rdblacklist=<replaceable>&lt;drivername&gt;</replaceable></envar>
</term>
<listitem>
<para>do not load kernel module &lt;drivername&gt;
This parameter can be specified multiple times.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rdloaddriver=<replaceable>&lt;drivername&gt;</replaceable></envar>
</term>
<listitem>
<para>force loading kernel module &lt;drivername&gt;
This parameter can be specified multiple times.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>Debug</title>
<variablelist>
<varlistentry>
<term>
<envar>rdinfo</envar>
</term>
<listitem>
<para>print informational output though &quot;quiet&quot; is set</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rdshell</envar>
</term>
<listitem>
<para>allow dropping to a shell, if root mounting fails</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rdinitdebug</envar>
</term>
<listitem>
<para>set -x for the dracut shell and logs to dmesg, console and <filename>/init.log</filename></para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rdbreak</envar>
</term>
<listitem>
<para>drop to a shell at the end</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rdbreak=</envar>
<replaceable>{cmdline|pre-udev|pre-trigger|initqueue|pre-mount|mount|pre-pivot}</replaceable>
</term>
<listitem>
<para>drop to a shell on defined breakpoint</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rdudevinfo</envar>
</term>
<listitem>
<para>set udev to loglevel info</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rdudevdebug</envar>
</term>
<listitem>
<para>set udev to loglevel debug</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd.timestamp</envar>
</term>
<listitem>
<para>export RDTIMESTAMP environment variable to init, which is set to the uptime of the dracut start.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>I18N</title>
<variablelist>
<varlistentry>
<term>
<envar>KEYMAP=</envar>
<replaceable>&lt;keymap base file name&gt;</replaceable>
</term>
<listitem>
<para>keyboard translation table loaded by loadkeys; taken from keymaps directory; will be written to <filename>/etc/sysconfig/keyboard</filename> in the initramfs, e.g.: <programlisting>KEYMAP=de-latin1-nodeadkeys</programlisting></para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>EXT_KEYMAPS=</envar>
<replaceable>&lt;list of keymap base file names&gt;</replaceable>
</term>
<listitem>
<para>list of extra keymaps to bo loaded (sep. by space); will be written to <filename>/etc/sysconfig/keyboard</filename> in the initramfs</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>UNICODE=</envar>
<replaceable>&lt;1|0&gt;</replaceable>
</term>
<listitem>
<para>boolean, indicating UTF-8 mode; will be written to <filename>/etc/sysconfig/i18n</filename> in the initramfs</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>SYSFONT=</envar>
<replaceable>&lt;font base file name&gt;</replaceable>
</term>
<listitem>
<para>console font; taken from consolefonts directory; will be written to <filename>/etc/sysconfig/i18n</filename> in the initramfs; e.g.: <programlisting>SYSFONT=LatArCyrHeb-16</programlisting></para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>CONTRANS=</envar>
<replaceable>&lt;console map base file name&gt;</replaceable>
</term>
<listitem>
<para>see description of &apos;-m&apos; parameter in setfont manual; taken from consoletrans directory; will be written to <filename>/etc/sysconfig/i18n</filename> in the initramfs</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>UNIMAP=</envar>
<replaceable>&lt;unicode table base file name&gt;</replaceable>
</term>
<listitem>
<para>see description of &apos;-u&apos; parameter in setfont manual; taken from unimaps directory; will be written to <filename>/etc/sysconfig/i18n</filename> in the initramfs</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>LANG=</envar>
<replaceable>&lt;locale&gt;</replaceable>
</term>
<listitem>
<para>taken from the environment; if no UNICODE is defined we set its value in basis of LANG value (whether it ends with &quot;.utf8&quot; (or similar) or not); will be written to <filename>/etc/sysconfig/i18n</filename> in the initramfs; e.g.: <programlisting>LANG=pl_PL.utf8</programlisting></para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>LC_ALL=</envar>
<replaceable>&lt;locale&gt;</replaceable>
</term>
<listitem>
<para>taken from the environment; will be written to <filename>/etc/sysconfig/i18n</filename> in the initramfs</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>LVM</title>
<variablelist>
<varlistentry>
<term>
<envar>rd_NO_LVM</envar>
</term>
<listitem>
<para>disable LVM detection</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_LVM_VG=<replaceable>&lt;volume group name&gt;</replaceable></envar>
</term>
<listitem>
<para>only activate the volume groups with the given name
<envar>rd_LVM_VG</envar> can be specified multiple times on the kernel command line.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_LVM_LV=<replaceable>&lt;logical volume name&gt;</replaceable></envar>
</term>
<listitem>
<para>only activate the logical volumes with the given name
<envar>rd_LVM_LV</envar> can be specified multiple times on the kernel command line.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_NO_LVMCONF</envar>
</term>
<listitem>
<para>remove any <filename>/etc/lvm/lvm.conf</filename>, which may exist in the initramfs</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>crypto LUKS</title>
<variablelist>
<varlistentry>
<term>
<envar>rd_NO_LUKS</envar>
</term>
<listitem>
<para>disable crypto LUKS detection</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_LUKS_UUID=<replaceable>&lt;luks uuid&gt;</replaceable></envar>
</term>
<listitem>
<para>only activate the LUKS partitions with the given UUID
Any &quot;luks-&quot; of the LUKS UUID is removed before comparing to <replaceable>&lt;luks uuid&gt;</replaceable>.
The comparisons also matches, if <replaceable>&lt;luks uuid&gt;</replaceable> is only the beginning of the
LUKS UUID, so you don&apos;t have to specify the full UUID.
This parameter can be specified multiple times.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_NO_CRYPTTAB</envar>
</term>
<listitem>
<para>do not check, if LUKS partition is in <filename>/etc/crypttab</filename></para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>crypt LUKS - experimental removable keys support</title>
<para>works only when plymouth module is not included</para>
<variablelist>
<varlistentry>
<term>
<envar>rd_LUKS_KEYPATH=</envar>
<replaceable>&lt;path to keyfile&gt;</replaceable>
</term>
<listitem>
<para>path to keyfile inside remove device filesystem</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_LUKS_KEYDEV_UUID=</envar>
<replaceable>&lt;rem. device uuid&gt;</replaceable>
</term>
<listitem>
<para>UUID of removalbe device storing keyfile; UUID doesn&apos;t have to be exact just like for <envar>rd_LUKS_UUID</envar></para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>MD</title>
<variablelist>
<varlistentry>
<term>
<envar>rd_NO_MD</envar>
</term>
<listitem>
<para>disable MD RAID detection</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_NO_MDIMSM</envar>
</term>
<listitem>
<para>no MD RAID for imsm/isw raids, use dmraid instead</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_NO_MDADMCONF</envar>
</term>
<listitem>
<para>ignore mdadm.conf included in initramfs</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_MD_UUID=<replaceable>&lt;md uuid&gt;</replaceable></envar>
</term>
<listitem>
<para>only activate the raid sets with the given UUID.
This parameter can be specified multiple times.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>DMRAID</title>
<variablelist>
<varlistentry>
<term>
<envar>rd_NO_DM</envar>
</term>
<listitem>
<para>disable DM RAID detection</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_DM_UUID=<replaceable>&lt;dmraid uuid&gt;</replaceable></envar>
</term>
<listitem>
<para>only activate the raid sets with the given UUID.
This parameter can be specified multiple times.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>Network</title>
<variablelist>
<varlistentry>
<term>
<envar>ip=</envar>
<replaceable>{dhcp|on|any|dhcp6|auto6}</replaceable>
</term>
<listitem>
<para>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.</para>
<para><constant>auto6</constant>: IPv6 autoconfiguration</para>
<para><constant>dhcp6</constant>: IPv6 DHCP</para>
</listitem>
</varlistentry>
<varlistentry>
<term><envar>ip=</envar><replaceable>&lt;interface&gt;</replaceable>:<replaceable>{dhcp|on|any|dhcp6|auto6}</replaceable></term>
<listitem>
<para>dhcp|on|any|dhcp6: get ip from dhcp server on a specific interface
auto6: do IPv6 autoconfiguration
This parameter can be specified multiple times.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><envar>ip=</envar><replaceable>&lt;client-IP&gt;</replaceable>:<optional>
<replaceable>&lt;server-id&gt;</replaceable>
</optional>:<replaceable>&lt;gateway-IP&gt;</replaceable>:<replaceable>&lt;netmask&gt;</replaceable>:<replaceable>&lt;client_hostname&gt;</replaceable>:<replaceable>&lt;interface&gt;</replaceable>:<replaceable>{none|off}</replaceable></term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><envar>ifname=</envar><replaceable>&lt;interface&gt;</replaceable>:<replaceable>&lt;MAC&gt;</replaceable></term>
<listitem>
<para>Assign network device name &lt;interface&gt; (ie eth0) to the NIC with MAC &lt;MAC&gt;.
Note letters in the MAC-address must be lowercase!
<remark>Note: If you use this option you <emphasis remap="B">must</emphasis> specify an ifname= argument for all interfaces used in ip= or fcoe= arguments.</remark>
This parameter can be specified multiple times.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>bootdev=</envar>
<replaceable>&lt;interface&gt;</replaceable>
</term>
<listitem>
<para>specify network interface to use routing and netroot information from.
Required if multiple ip= lines are used.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>nameserver=</envar>
<replaceable>&lt;IP&gt;</replaceable>
<optional><envar>nameserver</envar>=<replaceable>&lt;IP&gt;</replaceable> ...</optional>
</term>
<listitem>
<para>specify nameserver(s) to use</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>NFS</title>
<variablelist>
<varlistentry>
<term>
<envar>root=</envar>
<optional><replaceable>&lt;server-ip&gt;</replaceable>:</optional>
<replaceable>&lt;root-dir&gt;</replaceable>
<optional>:<replaceable>&lt;nfs-options&gt;</replaceable></optional>
</term>
<listitem>
<para>mount nfs share from &lt;server-ip&gt;:/&lt;root-dir&gt;, 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 &quot;:&quot; or &quot;,&quot; and are seperated by &quot;,&quot;.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><envar>root=</envar><constant>nfs</constant>:<optional><replaceable>&lt;server-ip&gt;</replaceable>:</optional><replaceable>&lt;root-dir&gt;</replaceable><optional>:<replaceable>&lt;nfs-options&gt;</replaceable></optional></term>
<term><envar>root=</envar>nfs4:<optional><replaceable>&lt;server-ip&gt;</replaceable>:</optional><replaceable>&lt;root-dir&gt;</replaceable><optional>:<replaceable>&lt;nfs-options&gt;</replaceable></optional></term>
<term>
<envar>root=</envar>
<replaceable>{dhcp|dhcp6}</replaceable>
</term>
<listitem>
<para>root=dhcp alone directs initrd to look at the DHCP root-path where NFS
options can be specified.
root-path=&lt;server-ip&gt;:&lt;root-dir&gt;[,&lt;nfs-options&gt;]
root-path=nfs:&lt;server-ip&gt;:&lt;root-dir&gt;[,&lt;nfs-options&gt;]
root-path=nfs4:&lt;server-ip&gt;:&lt;root-dir&gt;[,&lt;nfs-options&gt;]</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>root=</envar>
<filename>/dev/nfs</filename>
<envar> nfsroot=</envar>
<optional><replaceable>&lt;server-ip&gt;</replaceable>:</optional>
<replaceable>&lt;root-dir&gt;</replaceable>
<optional>:<replaceable>&lt;nfs-options&gt;</replaceable></optional>
</term>
<listitem>
<para><emphasis remap="B">Deprecated!</emphasis> kernel Documentation<filename>/filesystems/nfsroot.txt</filename> defines
this method.
This is supported by dracut, but not recommended.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar remap="B">rd_NFS_DOMAIN=</envar>
<replaceable>&lt;NFSv4 domain name&gt;</replaceable>
</term>
<listitem>
<para>Set the NFSv4 domain name. Will overwrite the settings in <filename>/etc/idmap.conf</filename>.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>iSCSI</title>
<variablelist>
<varlistentry>
<term><envar>root=</envar><constant>iscsi</constant>:<optional><replaceable>&lt;username&gt;</replaceable>:<replaceable>&lt;password&gt;</replaceable><optional>:<replaceable>&lt;reverse&gt;</replaceable>:<replaceable>&lt;password&gt;</replaceable></optional>@</optional><optional>
<replaceable>&lt;servername&gt;</replaceable>
</optional>:<optional>
<replaceable>&lt;protocol&gt;</replaceable>
</optional>:<optional>
<replaceable>&lt;port&gt;</replaceable>
</optional>:<optional>
<replaceable>&lt;LUN&gt;</replaceable>
</optional>:<replaceable>&lt;targetname&gt;</replaceable></term>
<listitem>
<para>protocol defaults to &quot;6&quot;, LUN defaults to &quot;0&quot;.</para>
<para>If the &quot;servername&quot; 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
&quot;servername&quot; field is not provided, then the &quot;targetname&quot; field is
then used in the Discovery Service stage in conjunction with other
associated fields.</para>
<para><ulink url="http://tools.ietf.org/html/rfc4173">http://tools.ietf.org/html/rfc4173</ulink></para>
<para>e.g.:<programlisting>root=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0 </programlisting></para>
<para>If servername is an IPv6 address, it has to be put in brackets. e.g.:
<programlisting>root=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0 </programlisting></para>
</listitem>
</varlistentry>
<varlistentry>
<term><envar>root=</envar><replaceable>???</replaceable><envar> netroot=</envar><constant>iscsi</constant>:<optional><replaceable>&lt;username&gt;</replaceable>:<replaceable>&lt;password&gt;</replaceable><optional>:<replaceable>&lt;reverse&gt;</replaceable>:<replaceable>&lt;password&gt;</replaceable></optional>@</optional><optional>
<replaceable>&lt;servername&gt;</replaceable>
</optional>:<optional>
<replaceable>&lt;protocol&gt;</replaceable>
</optional>:<optional>
<replaceable>&lt;port&gt;</replaceable>
</optional>:<optional>
<replaceable>&lt;LUN&gt;</replaceable>
</optional>:<replaceable>&lt;targetname&gt;</replaceable> ...</term>
<listitem>
<para>multiple netroot options allow setting up multiple iscsi disks. e.g.:
<programlisting>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 </programlisting></para>
<para>If servername is an IPv6 address, it has to be put in brackets.
e.g.:
<programlisting>netroot=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0</programlisting></para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>root=<replaceable>???</replaceable></envar>
<envar> iscsi_initiator=<replaceable>&lt;initiator&gt; </replaceable></envar>
<envar>iscsi_target_name=<replaceable>&lt;target_name&gt; </replaceable></envar>
<envar>iscsi_target_ip=<replaceable>&lt;target ip&gt; </replaceable></envar>
<envar>iscsi_target_port=<replaceable>&lt;target port&gt; </replaceable></envar>
<envar>iscsi_target_group=<replaceable>&lt;target group&gt; </replaceable></envar>
<envar>iscsi_username=<replaceable>&lt;username&gt; </replaceable></envar>
<envar>iscsi_password=<replaceable>&lt;password&gt; </replaceable></envar>
<envar>iscsi_in_username=<replaceable>&lt;in username&gt; </replaceable></envar>
<envar>iscsi_in_password=<replaceable>&lt;in password&gt; </replaceable></envar>
</term>
<listitem>
<para>manually specify all iscsistart parameter (see <userinput>iscsistart&nbsp;--help</userinput>)</para>
</listitem>
</varlistentry>
<varlistentry>
<term><envar>root=</envar>???<envar> iscsi_firmware</envar></term>
<listitem>
<para>will read the iscsi parameter from the BIOS firmware</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>FCoE</title>
<variablelist>
<varlistentry>
<term><envar>netroot=</envar><constant>fcoe</constant>:<replaceable>&lt;interface|MAC&gt;</replaceable>:<replaceable>{dcb|nodcb}</replaceable></term>
<listitem>
<para>Try to connect to a FCoE SAN through the NIC specified by <replaceable>&lt;interface&gt;</replaceable> or <replaceable>&lt;MAC&gt;</replaceable>,
for the second argument, currently only nodcb is supported. <remark>Note: letters in the MAC-address must be lowercase!</remark></para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>NBD</title>
<variablelist>
<varlistentry>
<term><envar>root=</envar><constant>nbd</constant>:<replaceable>&lt;server&gt;</replaceable>:<replaceable>&lt;port&gt;</replaceable><optional>:<replaceable>&lt;fstype&gt;</replaceable></optional><optional>:<replaceable>&lt;mountopts&gt;</replaceable></optional></term>
<listitem>
<para>mount nbd share from &lt;server&gt;</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>root=dhcp</envar>
</term>
<listitem>
<para>with dhcp root-path=nbd:&lt;server&gt;:&lt;port&gt;[:&lt;fstype&gt;][:&lt;mountopts&gt;]
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.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>DASD</title>
<variablelist>
<varlistentry>
<term><envar>rd_DASD_MOD=</envar>....</term>
<listitem>
<para>same syntax as the kernel module parameter (s390 only)</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_DASD=</envar>
<replaceable>&lt;dasd_adaptor device bus ID&gt;</replaceable>
<optional>,readonly=<replaceable>X</replaceable></optional>
<optional>,use_diag=<replaceable>X</replaceable></optional>
<optional>,erplog=<replaceable>X</replaceable></optional>
</term>
<listitem>
<para>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.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>ZFCP</title>
<variablelist>
<varlistentry>
<term><envar>rd_ZFCP=</envar><replaceable>&lt;zfcp adaptor device bus ID&gt;</replaceable>,<replaceable>&lt;WWPN&gt;</replaceable>,<replaceable>&lt;FCPLUN&gt;</replaceable></term>
<listitem>
<para>rd_ZFCP can be specified multiple times on the kernel command line. e.g.: <programlisting>rd_ZFCP=0.0.4000,0x5005076300C213e9,0x5022000000000000</programlisting></para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<envar>rd_NO_ZFCPCONF</envar>
</term>
<listitem>
<para>ignore zfcp.conf included in the initramfs</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>ZNET</title>
<variablelist>
<varlistentry>
<term><envar>rd_ZNET=</envar><replaceable>&lt;nettype&gt;</replaceable>,<replaceable>&lt;subchannels&gt;</replaceable>,<replaceable>&lt;options&gt;</replaceable></term>
<listitem>
<para>rd_ZNET can be specified multiple times on the kernel command line. e.g.:
<programlisting>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</programlisting></para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
<refsect2>
<title>Plymouth Boot Splash</title>
<variablelist>
<varlistentry>
<term>
<envar>rd_NO_PLYMOUTH</envar>
</term>
<listitem>
<para>do not start plymouth. This will not work with encrypted partitions.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
</refsect1>
<refsect1>
<title>Configuration in the Initramfs</title>
<variablelist>
<varlistentry>
<term>
<filename>/conf/conf.d/</filename>
</term>
<listitem>
<para>Any files found in <filename>/conf/conf.d/</filename> will be sourced in the initramfs to
set initial values. Command line options will override these values
set in the configuration files.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<filename>/etc/cmdline</filename>
</term>
<listitem>
<para>Can contain additional command line options.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry>
<refentrytitle>dracut</refentrytitle>
<manvolnum>8</manvolnum>
</citerefentry>
<citerefentry>
<refentrytitle>dracut.conf</refentrytitle>
<manvolnum>5</manvolnum>
</citerefentry>
</para>
</refsect1>
</refentry>