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.
33 .BR \-k ", " \-\-kmoddir " \fI{DIR}\fR
34 specify the directory, where to look for kernel modules
36 .BR " \-\-fwdir " \fI{DIR}\fR
37 specify additional directory, where to look for firmwares
40 only install kernel drivers and firmware files
43 do not install kernel drivers and firmware files
46 strip binaries in the initramfs (default)
49 do not strip binaries in the initramfs
52 display help text and exit.
55 output debug information of the build process
57 .BR \-v ", " \-\-verbose
58 verbose output during the build process
60 .BR \-c ", " \-\-conf " \fIFILE\fR"
61 specify configuration file to use.
65 .BR \-l ", " \-\-local
66 local mode. Use modules from the current working
67 directory instead of the system-wide installed in
68 .IR /usr/share/dracut/modules.d .
69 Useful when running dracut from a git checkout.
71 .BR \-H ", " \-\-hostonly
72 Host-Only mode: Install only what is needed for
73 booting the local host instead of a generic host.
75 .BR \-i ", " \-\-include " \fISOURCE\fR" "" " \fITARGET\fR"
76 include the files in the SOURCE directory into the
77 target directory in the final initramfs.
79 .BR \-I ", " \-\-install " \fILIST\fR"
80 install the space separated list of files into the initramfs.
82 .SH KERNEL COMMAND LINE
83 The root filesystem used by the kernel is specified in the boot configuration
84 file, as always. The traditional \fBroot=/dev/hda1\fR style device
85 specification is allowed. If a label is used, as in \fBroot=LABEL=rootPart\fR
86 the initrd will search all available devices for an ext2 or ext3 filesystem
87 with the appropriate label, and mount that device as the root filesystem.
88 \fBroot=UUID=uuidnumber\fR will mount the partition with that UUID as the
93 .B init=<path to real init>
95 .B root=<path to blockdevice>
96 specify e.g. \fI/dev/sda1\fR or
97 \fI/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1\fR
100 e.g. LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=de-latin1-nodeadkeys
102 .B KEYBOARDTYPE=sun|pc
103 will be written to /etc/sysconfig/keyboard in the initramfs
105 .B KEYTABLE=<keytable filename>
106 will be written to /etc/sysconfig/keyboard in the initramfs
108 .B SYSFONT= Console font
109 will be written to /etc/sysconfig/i18n in the initramfs
111 .B SYSFONTACM= Unicode font map
112 will be written to /etc/sysconfig/i18n in the initramfs
114 .B UNIMAP= Unicode font map
115 will be written to /etc/sysconfig/i18n in the initramfs
118 will be written to /etc/sysconfig/i18n in the initramfs
120 .SH Bootsplash - plymouth
122 .B rd_plytheme=<theme name>
123 specify the plymouth bootsplash theme (fallback is text)
128 disable LVM detection
130 .B rd_LVM_VG=<volume group name>
131 only activate the volume groups with the given name
136 disable crypto LUKS detection
138 .B rd_LUKS_UUID=<luks uuid>
139 only activate the LUKS partitions with the given UUID
144 disable MD RAID detection
147 no MD RAID for imsm/isw raids, use dmraid instead
149 .B rd_MD_UUID=<md uuid>
150 only activate the raid sets with the given UUID
155 disable DM RAID detection
157 .B rd_DM_UUID=<dmraid uuid>
158 only activate the raid sets with the given UUID
163 same syntax as the kernel module parameter (s390 only)
168 get IP from dhcp server, root-path option from dhcp specifies root location
172 .B root=[<server-ip>:]<root-dir>[:<nfs-options>]
173 mount nfs share from <server-ip>:/<root-dir>, if no server-ip is given,
174 use dhcp next_server.
175 NFS options can be appended with the prefix "." or ","
177 .B root=nfs:[<server-ip>:]<root-dir>[:<nfs-options>]
179 .B root=nfs4:[<server-ip>:]<root-dir>[:<nfs-options>]
182 root=dhcp alone directs initrd to look at the DHCP root-path where NFS
183 options can be specified.
184 root-path=<server-ip>:<root-dir>[,<nfs-options>]
185 root-path=nfs:<server-ip>:<root-dir>[,<nfs-options>]
186 root-path=nfs4:<server-ip>:<root-dir>[,<nfs-options>]
188 .B root=/dev/nfs nfsroot=[<server-ip>:]<root-dir>[,<nfs-options>]
189 \fBDeprecated!\fR kernel Documentation/filesystems/nfsroot.txt defines
191 This is supported by dracut but not recommended.
195 .B root=iscsi:[username:password[reverse:password]@][<servername>]:[<protocol>]:[<port>]:[<LUN>]:<targetname>
196 protocol defaults to "6", LUN defaults to "0".
198 If the "servername" field is provided by BOOTP or DHCP, then that
199 field is used in conjunction with other associated fields to contact
200 the boot server in the Boot stage (Section 7). However, if the
201 "servername" field is not provided, then the "targetname" field is
202 then used in the Discovery Service stage in conjunction with other
205 http://tools.ietf.org/html/rfc4173
208 .B root=iscsi:[username:password[:reverse:password]@][<servername>]:[<protocol>]:[<port>]:[<LUN>]:<targetname>
209 e.g. root=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
211 .B root=??? netroot=iscsi:[username:password[:reverse:password]@][<servername>]:[<protocol>]:[<port>]:[<LUN>]:<targetname> ...
212 multiple netroot options allow setting up multiple iscsi disks
214 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
215 .B not yet implemented
217 .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=
219 .B root=??? iscsi_firmware
220 will read the iscsi parameter from the BIOS firmware
224 .B root=nbd:<server>:<port>[:<fstype>][:<mountopts>]
225 mount nbd share from <server>
228 with dhcp root-path=nbd:<server>:<port>[:<fstype>][:<mountopts>]
229 root=dhcp alone directs initrd to look at the DHCP root-path where NBD options can be specified.
230 This syntax is only usable in cases where you are directly mounting the volume as the rootfs.
233 .TP bootdev=<interface>
234 .B specify the network interface to boot from
237 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.
239 .B ip=<interface>:{dhcp|on|any}
240 get ip from dhcp server on a specific interface
242 .B ip=<client-IP-number>:[<server-id>]:<gateway-IP-number>:<netmask>:<client-hostname>:<interface>:{none|off}
243 explicit network configuration
247 .B rdblacklist=<drivername>
248 do not load kernel module <drivername>
253 allow dropping to a shell, if root mounting fails
256 set -x for the dracut shell
259 drop to a shell at the end
261 .B rdbreak={pre-udev|pre-mount|mount|pre-pivot|commandline|initqueue}
262 drop to a shell on defined breakpoint
265 set udev to loglevel info
268 set udev to loglevel debug
271 debug network scripts in dracut. Output is written to /tmp/
273 .SH CONFIGURATION IN INITRAMFS
276 Any files found in /conf/conf.d/ will be sourced in the initramfs to
277 set initial values. Command line options will override these values
278 set in the configuration files.
282 Andreas Thienemann <andreas@bawue.net>
283 Bill Nottingham <notting@redhat.com>
284 Dave Jones <davej@redhat.com>
285 David Dillow <dave@thedillows.org>
286 Harald Hoyer <harald@redhat.com>
287 Jeremy Katz <katzj@redhat.com>
288 Peter Jones <pjones@redhat.com>
289 Seewer Philippe <philippe.seewer@bfh.ch>
290 Victor Lowther <victor.lowther@gmail.com>
291 Warren Togami <wtogami@redhat.com>
294 The dracut command is part of the dracut package and is available from
295 https://sourceforge.net/apps/trac/dracut/wiki