1 .TH DRACUT 8 "June 2009" "Linux"
3 switch_root \- switch to another filesystem as the root of the mount tree.
5 \fBdracut\fR [\fIOPTION\fR]... \fI<image>\fR \fI<kernel-version>\fR
9 \fBdracut\fR creates an initial image used by the kernel for
10 preloading the block device modules (such as IDE, SCSI or RAID)
11 which are needed to access the root filesystem.
15 .BR \-f ", " \-\-force
16 overwrite existing initramfs file.
18 .BR \-m ", " \-\-modules " \fILIST\fR"
19 specify a space-separated list of dracut modules to call
20 when building the initramfs.
21 Modules are located in
22 .IR /usr/share/dracut/modules.d .
24 .BR \-o ", " \-\-omit " \fILIST\fR"
25 omit a space-separated list of dracut modules.
27 .BR \-a ", " \-\-add " \fILIST\fR"
28 add a space-separated list of dracut modules.
30 .BR \-d ", " \-\-drivers " \fILIST\fR"
31 specify a space-separated list of kernel modules to include in the initramfs.
34 display help text and exit.
37 output debug information of the build process
39 .BR \-v ", " \-\-verbose
40 verbose output during the build process
42 .BR \-c ", " \-\-conf " \fIFILE\fR"
43 specify configuration file to use.
47 .BR \-l ", " \-\-local
48 local mode. Use modules from the current working
49 directory instead of the system-wide installed in
50 .IR /usr/share/dracut/modules.d .
51 Useful when running dracut from a git checkout.
53 .BR \-H ", " \-\-hostonly
54 Host-Only mode: Install only what is needed for
55 booting the local host instead of a generic host.
57 .BR \-i ", " \-\-include " \fISOURCE\fR" "" " \fITARGET\fR"
58 include the files in the SOURCE directory into the
59 target directory in the final initramfs.
61 .BR \-I ", " \-\-install " \fILIST\fR"
62 install the space separated list of files into the initramfs.
64 .SH KERNEL COMMAND LINE
65 The root filesystem used by the kernel is specified in the boot configuration
66 file, as always. The traditional \fBroot=/dev/hda1\fR style device
67 specification is allowed. If a label is used, as in \fBroot=LABEL=rootPart\fR
68 the initrd will search all available devices for an ext2 or ext3 filesystem
69 with the appropriate label, and mount that device as the root filesystem.
70 \fBroot=UUID=uuidnumber\fR will mount the partition with that UUID as the
75 .B init=<path to real init>
77 .B root=<path to blockdevice>
78 specify e.g. \fI/dev/sda1\fR or
79 \fI/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1\fR
82 e.g. LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=de-latin1-nodeadkeys
84 .B KEYBOARDTYPE=sun|pc
85 will be written to /etc/sysconfig/keyboard in the initramfs
87 .B KEYTABLE=<keytable filename>
88 will be written to /etc/sysconfig/keyboard in the initramfs
90 .B SYSFONT= Console font
91 will be written to /etc/sysconfig/i18n in the initramfs
93 .B SYSFONTACM= Unicode font map
94 will be written to /etc/sysconfig/i18n in the initramfs
96 .B UNIMAP= Unicode font map
97 will be written to /etc/sysconfig/i18n in the initramfs
100 will be written to /etc/sysconfig/i18n in the initramfs
105 disable LVM detection
107 .B rd_LVM_VG=<volume group name>
108 only activate the volume groups with the given name
113 disable crypto LUKS detection
115 .B rd_LUKS_UUID=<luks uuid>
116 only activate the LUKS partitions with the given UUID
121 disable MD RAID detection
123 .B rd_MD_UUID=<md uuid>
124 only activate the raid sets with the given UUID
129 disable DM RAID detection
131 .B rd_DM_UUID=<dmraid uuid>
132 only activate the raid sets with the given UUID
137 get IP from dhcp server, root-path option from dhcp specifies root location
141 .B root=[<server-ip>:]<root-dir>[:<nfs-options>]
142 mount nfs share from <server-ip>:/<root-dir>, if no server-ip is given,
143 use dhcp next_server.
144 NFS options can be appended with the prefix "." or ","
146 .B root=nfs:[<server-ip>:]<root-dir>[:<nfs-options>]
148 .B root=nfs4:[<server-ip>:]<root-dir>[:<nfs-options>]
151 root=dhcp alone directs initrd to look at the DHCP root-path where NFS
152 options can be specified.
153 root-path=<server-ip>:<root-dir>[,<nfs-options>]
154 root-path=nfs:<server-ip>:<root-dir>[,<nfs-options>]
155 root-path=nfs4:<server-ip>:<root-dir>[,<nfs-options>]
157 .B root=/dev/nfs nfsroot=[<server-ip>:]<root-dir>[,<nfs-options>]
158 \fBDeprecated!\fR kernel Documentation/filesystems/nfsroot.txt defines
160 This is supported by dracut but not recommended.
164 .B root=iscsi:[<servername>]:[<protocol>]:[<port>]:[<LUN>]:<targetname>
165 protocol defaults to "6", LUN defaults to "0".
167 If the "servername" field is provided by BOOTP or DHCP, then that
168 field is used in conjunction with other associated fields to contact
169 the boot server in the Boot stage (Section 7). However, if the
170 "servername" field is not provided, then the "targetname" field is
171 then used in the Discovery Service stage in conjunction with other
174 http://tools.ietf.org/html/rfc4173
177 .B root=iscsi:[<servername>]:[<protocol>]:[<port>]:[<LUN>]:<targetname>
178 e.g. root=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
181 .B root=??? netroot=iscsi:[<servername>]:[<protocol>]:[<port>]:[<LUN>]:<targetname> ...
182 multiple netroot options allow setting up multiple iscsi disks
184 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
185 .B not yet implemented
187 .B 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=
190 .B root=??? iscsi_firmware
191 will read the iscsi parameter from the BIOS firmware
195 .B root=nbd:<server>:<port>[:<fstype>][:<mountopts>]
196 mount nbd share from <server>
199 with dhcp root-path=nbd:<server>:<port>[:<fstype>][:<mountopts>]
200 root=dhcp alone directs initrd to look at the DHCP root-path where NBD options can be specified.
201 This syntax is only usable in cases where you are directly mounting the volume as the rootfs.
204 .TP bootdev=<interface>
205 .B specify the network interface to boot from
208 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.
210 .B ip=<interface>:[dhcp|on|any]
211 get ip from dhcp server on a specific interface
213 .B ip=<client-IP-number>:<gateway-IP-number>:<netmask>:<client-hostname>:<interface>:[dhcp|on|any|]
214 explicit network configuration
218 .B rdblacklist=<drivername>
219 do not load kernel module <drivername>
224 drop to a shell, if the imitramfs fails
227 set -x for the dracut shell
229 .B rdbreak=[pre-udev|pre-mount|mount|pre-pivot|]
230 drop the shell on defined breakpoint
233 set udev to loglevel info
236 set udev to loglevel debug
239 debug network scripts in dracut. Output is written to /tmp/
241 .SH CONFIGURATION IN INITRAMFS
244 Any files found in /conf/conf.d/ will be sourced in the initramfs to
245 set initial values. Command line options will override these values
246 set in the configuration files.
250 Andreas Thienemann <andreas@bawue.net>
251 Bill Nottingham <notting@redhat.com>
252 Dave Jones <davej@redhat.com>
253 David Dillow <dave@thedillows.org>
254 Harald Hoyer <harald@redhat.com>
255 Jeremy Katz <katzj@redhat.com>
256 Peter Jones <pjones@redhat.com>
257 Seewer Philippe <philippe.seewer@bfh.ch>
258 Victor Lowther <victor.lowther@gmail.com>
259 Warren Togami <wtogami@redhat.com>
262 The dracut command is part of the dracut package and is available from
263 https://sourceforge.net/apps/trac/dracut/wiki