9 dracut - low-level tool for generating an initramfs image
13 *dracut* [__OPTION...__] [__<image>__ [__<kernel version>__]]
18 Create an initramfs <image> for the kernel with the version <kernel version>.
19 If <kernel version> is omitted, then the version of the actual running
20 kernel is used. If <image> is omitted or empty, then the default location
21 /boot/initramfs-<kernel version>.img is used.
23 dracut creates an initial image used by the kernel for preloading the block
24 device modules (such as IDE, SCSI or RAID) which are needed to access the root
25 filesystem, mounting the root filesystem and booting into the real system.
27 At boot time, the kernel unpacks that archive into RAM disk, mounts and uses it
28 as initial root file system. All finding of the root device happens in this
31 For a complete list of kernel command line options see *dracut.cmdline*(7).
33 If you are dropped to an emergency shell, while booting your initramfs,
34 the file _/run/initramfs/rdsosreport.txt_ is created, which can be safed to a
35 (to be mounted by hand) partition (usually /boot) or a USB stick.
36 Additional debugging info can be produced by adding **rd.debug** to the kernel
37 command line. _/run/initramfs/rdsosreport.txt_ contains all logs and the output
38 of some tools. It should be attached to any report about dracut problems.
43 include::dracut.usage.asc[]
47 **--kver** _<kernel version>_::
48 set the kernel version. This enables to specify the kernel version, without
49 specifying the location of the initramfs image. For example:
51 # dracut --kver 3.5.0-0.rc7.git1.2.fc18.x86_64
55 overwrite existing initramfs file.
57 **-m, --modules** _<list of dracut modules>_::
58 specify a space-separated list of dracut modules to call when building the
59 initramfs. Modules are located in _/usr/lib/dracut/modules.d_. This
60 parameter can be specified multiple times.
63 ===============================
64 If [LIST] has multiple arguments, then you have to put these in quotes. For
67 # dracut --modules "module1 module2" ...
69 ===============================
71 **-o, --omit** _<list of dracut modules>_::
72 omit a space-separated list of dracut modules. This parameter can be
73 specified multiple times.
76 ===============================
77 If [LIST] has multiple arguments, then you have to put these in quotes. For
80 # dracut --omit "module1 module2" ...
82 ===============================
84 **-a, --add** _<list of dracut modules>_::
85 add a space-separated list of dracut modules to the default set of modules.
86 This parameter can be specified multiple times.
89 ===============================
90 If [LIST] has multiple arguments, then you have to put these in quotes. For
93 # dracut --add "module1 module2" ...
95 ===============================
97 **--force-add** _<list of dracut modules>_::
98 force to add a space-separated list of dracut modules to the default set of
99 modules, when -H is specified. This parameter can be specified multiple
103 ===============================
104 If [LIST] has multiple arguments, then you have to put these in quotes. For
107 # dracut --force-add "module1 module2" ...
109 ===============================
111 **-d, --drivers** _<list of kernel modules>_::
112 specify a space-separated list of kernel modules to exclusively include
113 in the initramfs. The kernel modules have to be specified without the ".ko"
114 suffix. This parameter can be specified multiple times.
117 ===============================
118 If [LIST] has multiple arguments, then you have to put these in quotes. For
121 # dracut --drivers "kmodule1 kmodule2" ...
123 ===============================
125 **--add-drivers** _<list of kernel modules>_::
126 specify a space-separated list of kernel modules to add to the initramfs.
127 The kernel modules have to be specified without the ".ko" suffix. This
128 parameter can be specified multiple times.
131 ===============================
132 If [LIST] has multiple arguments, then you have to put these in quotes. For
135 # dracut --add-drivers "kmodule1 kmodule2" ...
137 ===============================
139 **--omit-drivers** _<list of kernel modules>_::
140 specify a space-separated list of kernel modules not to add to the
142 The kernel modules have to be specified without the ".ko" suffix. This
143 parameter can be specified multiple times.
146 ===============================
147 If [LIST] has multiple arguments, then you have to put these in quotes. For
150 # dracut --omit-drivers "kmodule1 kmodule2" ...
152 ===============================
154 **--filesystems** _<list of filesystems>_::
155 specify a space-separated list of kernel filesystem modules to exclusively
156 include in the generic initramfs. This parameter can be specified multiple
160 ===============================
161 If [LIST] has multiple arguments, then you have to put these in quotes. For
164 # dracut --filesystems "filesystem1 filesystem2" ...
166 ===============================
168 **-k, --kmoddir** _<kernel directory>_::
169 specify the directory, where to look for kernel modules
171 **--fwdir** _<dir>[:<dir>...]++_::
172 specify additional directories, where to look for firmwares. This parameter
173 can be specified multiple times.
175 **--kernel-cmdline <parameters>**::
176 specify default kernel command line parameters
180 only install kernel drivers and firmware files
183 do not install kernel drivers and firmware files
185 **--early-microcode**::
186 Combine early microcode with ramdisk
188 **--no-early-microcode**::
189 Do not combine early microcode with ramdisk
191 **--print-cmdline**::
192 print the kernel command line for the current disk layout
195 include local _/etc/mdadm.conf_
198 do not include local _/etc/mdadm.conf_
201 include local _/etc/lvm/lvm.conf_
204 do not include local _/etc/lvm/lvm.conf_
207 add a space-separated list of fsck tools, in addition to _dracut.conf_'s
208 specification; the installation is opportunistic (non-existing tools are
212 ===============================
213 If [LIST] has multiple arguments, then you have to put these in quotes. For
216 # dracut --fscks "fsck.foo barfsck" ...
218 ===============================
221 inhibit installation of any fsck tools
224 strip binaries in the initramfs (default)
227 do not strip binaries in the initramfs
230 prelink binaries in the initramfs (default)
233 do not prelink binaries in the initramfs
236 hardlink files in the initramfs (default)
239 do not hardlink files in the initramfs
241 **--prefix** _<dir>_::
242 prefix initramfs files with the specified directory
245 do not prefix initramfs files (default)
248 display help text and exit.
251 output debug information of the build process
254 increase verbosity level (default is info(4))
256 **-q, --quiet**:: decrease verbosity level (default is info(4))
258 **-c, --conf** _<dracut configuration file>_::
259 specify configuration file to use.
264 **--confdir** _<configuration directory>_::
265 specify configuration directory to use.
270 **--tmpdir** _<temporary directory>_::
271 specify temporary directory to use.
276 **--sshkey** _<sshkey file>_:: ssh key file used with ssh-client module.
278 **--logfile** _<logfile>_:: logfile to use; overrides any setting from
279 the configuration files.
282 _/var/log/dracut.log_
285 activates the local mode. dracut will use modules from the current working
286 directory instead of the system-wide installed modules in
287 _/usr/lib/dracut/modules.d_.
288 This is useful when running dracut from a git checkout.
291 Host-Only mode: Install only what is needed for booting the local host
292 instead of a generic host and generate host-specific configuration.
296 If chrooted to another root other than the real root device, use "--fstab" and
297 provide a valid _/etc/fstab_.
300 **-N, --no-hostonly**::
301 Disable Host-Only mode
303 **--persistent-policy** _<policy>_::
304 Use _<policy>_ to address disks and partitions.
305 _<policy>_ can be any directory name found in /dev/disk.
306 E.g. "by-uuid", "by-label"
309 Use _/etc/fstab_ instead of _/proc/self/mountinfo_.
311 **--add-fstab** _<filename>_::
312 Add entries of _<filename>_ to the initramfs /etc/fstab.
314 **--mount** "_<device>_ _<mountpoint>_ _<filesystem type>_ _<filesystem options>_"::
315 Mount _<device>_ on _<mountpoint>_ with _<filesystem type>_ and _<filesystem
316 options>_ in the initramfs
318 **--add-device** _<device>_ ::
319 Bring up _<device>_ in initramfs, _<device>_ should be the device name.
320 This can be useful in hostonly mode for resume support when your swap is on
321 LVM or an encrypted partition.
322 [NB --device can be used for compatibility with earlier releases]
324 **-i, --include** _<SOURCE>_ _<TARGET>_::
325 include the files in the SOURCE directory into the
326 TARGET directory in the final initramfs. If SOURCE is a file, it will be
327 installed to TARGET in the final initramfs. This parameter can be specified
330 **-I, --install** _<file list>_::
331 install the space separated list of files into the initramfs.
334 ===============================
335 If [LIST] has multiple arguments, then you have to put these in quotes. For
338 # dracut --install "/bin/foo /sbin/bar" ...
340 ===============================
343 Compress the generated initramfs using gzip. This will be done by default,
344 unless another compression option or --no-compress is passed. Equivalent to
348 Compress the generated initramfs using bzip2.
352 Make sure your kernel has bzip2 decompression support compiled in, otherwise you
353 will not be able to boot. Equivalent to "--compress=bzip2"
357 Compress the generated initramfs using lzma.
361 Make sure your kernel has lzma decompression support compiled in, otherwise you
362 will not be able to boot. Equivalent to "lzma --compress=lzma -9"
366 Compress the generated initramfs using xz.
370 Make sure your kernel has xz decompression support compiled in, otherwise you
371 will not be able to boot. Equivalent to
372 "lzma --compress=xz --check=crc32 --lzma2=dict=1MiB"
376 Compress the generated initramfs using lzop.
379 Make sure your kernel has lzo decompression support compiled in, otherwise you
380 will not be able to boot.
384 Compress the generated initramfs using lz4.
387 Make sure your kernel has lz4 decompression support compiled in, otherwise you
388 will not be able to boot.
391 **--compress** _<compressor>_::
392 Compress the generated initramfs using the passed compression program. If
393 you pass it just the name of a compression program, it will call that
394 program with known-working arguments. If you pass a quoted string with
395 arguments, it will be called with exactly those arguments. Depending on what
396 you pass, this may result in an initramfs that the kernel cannot decompress.
399 Do not compress the generated initramfs. This will override any other
403 List all available dracut modules.
405 **-M, --show-modules**::
406 Print included module's name to standard output during build.
409 Keep the initramfs temporary directory for debugging purposes.
412 Print out the module install size
415 Output profile information of the build process
418 Mount / and /usr read-only by default.
420 **-L, --stdlog** _<level>_::
421 [0-6] Specify logging level (to standard error)
423 0 - suppress any messages
424 1 - only fatal errors
428 5 - debug info (here starts lots of output)
429 6 - trace info (and even more)
432 **--regenerate-all**::
433 Regenerate all initramfs images at the default location with the kernel
434 versions found on the system. Additional parameters are passed through.
438 _/var/log/dracut.log_::
439 logfile of initramfs image creation
442 logfile of initramfs image creation, if _/var/log/dracut.log_ is not
448 _/etc/dracut.conf.d/*.conf_::
451 _/usr/lib/dracut/dracut.conf.d/*.conf_::
454 Configuration in the initramfs
455 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
457 Any files found in _/etc/conf.d/_ will be sourced in the initramfs to
458 set initial values. Command line options will override these values
459 set in the configuration files.
462 Can contain additional command line options. Deprecated, better use
463 /etc/cmdline.d/*.conf.
465 _/etc/cmdline.d/*.conf_::
466 Can contain additional command line options.
470 The dracut command is part of the dracut package and is available from
471 link:$$https://dracut.wiki.kernel.org$$[https://dracut.wiki.kernel.org]
493 *dracut.cmdline*(7) *dracut.conf*(5)