From Fedora Project Wiki
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== Standard ==
 
== Standard ==
  
* init=<path to real init>
+
<pre>init=<path to real init></pre>
* root=<path to blockdevice>
+
<pre>root=<path to blockdevice></pre>
 
{{admon/note| Specify e.g. /dev/sda1 or /dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1}}
 
{{admon/note| Specify e.g. /dev/sda1 or /dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1}}
  

Revision as of 15:06, 2 July 2009

Dracut kernel command line parameters

Limitations

  • Command line length: 2048
  • dhcp root-path: 255

Configuration in initrd

/conf/conf.d/* 
Note.png
Command line options can override values set here

Standard

init=<path to real init>
root=<path to blockdevice>
Note.png
Specify e.g. /dev/sda1 or /dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1

DHCP

  • root=dhcp
Note.png
Get IP from dhcp server, root-path option from dhcp specifies root location.

NFSv3

  • root=[<server-ip>:]<root-dir>[:<nfs-options>]
Note.png
Mount nfs share from <server-ip>:/<root-dir> If no server-ip is given use dhcp next_server. nfs-options can be appended with the prefix ":" or ","
  • root=dhcp
Note.png
  • root-path=<server-ip>:<root-dir>[,<nfs-options>]
  • Deprecated root=/dev/nfs nfsroot=[<server-ip>:]<root-dir>[,<nfs-options>]
Note.png
Kernel Documentation/filesystems/nfsroot.txt defines this method. This is supported by dracut but not recommended.

NFSv4

  • root=nfs4:[<server-ip>:]<root-dir>[:<nfs-options>]
Note.png
mount nfsv4 share from <server-ip>:/<root-dir>. If no server-ip is given, use dhcp next_server. nfs-options can be appended with the prefix ":" or ","
  • root=dhcp
Note.png

iSCSI

  • root=iscsi:[<servername>]:[<protocol>]:[<port>]:[<LUN>]:<targetname>::
Note.png
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.[RFC4173]
  • root=??? iscsiroot=...::
  • root=??? iscsi_initiator= iscsi_target_name= iscsi_target_ip= iscsi_target_port= iscsi_target_group= iscsi_username= iscsi_password= iscsi_in_username= iscsi_in_password=::
  • root=??? iscsi_firmware::

NBD

  • root=nbd:<server>:<port>[:<fstype>][:<mountopts>]
Note.png
Mount nbd share from <server>.
  • root=dhcp
Note.png

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.

Network

  • ip=[dhcp|on|any]
Note.png
  • ip=<interface>:[dhcp|on|any]
Note.png
Get ip from dhcp server on a specific interface.
  • ip=<client-IP-number>:<gateway-IP-number>:<netmask>:<client-hostname>:<interface>:[dhcp|on|any|]
Note.png
Explicit network configuration

Misc

  • rdblacklist=<modulename>
Note.png
TBD: do not load modulename.

Debug ¶

   * rdinitdebug
         o set -x for the dracut shell 
   * rdbreak=[pre-udev|pre-mount|mount|pre-pivot|]
         o drop the shell on defined breakpoint 
   * rdudevinfo
         o set udev to loglevel info 
   * rdudevdebug
         o set udev to loglevel debug 
   * rdnetdebug
         o debug network scripts in dracut