DRACUT(8) dracut DRACUT(8)
NAME
dracut - low-level tool for generating an initramfs image
SYNOPSIS
dracut [OPTION...] [<image> [<kernel version>]]
DESCRIPTION
dracut creates an initial image used by the kernel for preloading the block device modules (such as IDE, SCSI or RAID) which are needed to
access the root filesystem, mounting the root filesystem and booting into the real system.
At boot time, the kernel unpacks that archive into RAM disk, mounts and uses it as initial root file system. All finding of the root device
happens in this early userspace.
For a complete list of kernel command line options see dracut.cmdline(7)
OPTIONS
-f, --force
overwrite existing initramfs file.
-m, --modules <list of dracut modules>
specify a space-separated list of dracut modules to call when building the initramfs. Modules are located in /usr/lib/dracut/modules.d.
This parameter can be specified multiple times.
Note
If [LIST] has multiple arguments, then you have to put these in quotes. For example:
# dracut --modules "module1 module2" ...
-o, --omit <list of dracut modules>
omit a space-separated list of dracut modules. This parameter can be specified multiple times.
Note
If [LIST] has multiple arguments, then you have to put these in quotes. For example:
# dracut --omit "module1 module2" ...
-a, --add <list of dracut modules>
add a space-separated list of dracut modules to the default set of modules. This parameter can be specified multiple times.
Note
If [LIST] has multiple arguments, then you have to put these in quotes. For example:
# dracut --add "module1 module2" ...
--force-add <list of dracut modules>
force to add a space-separated list of dracut modules to the default set of modules, when -H is specified. This parameter can be
specified multiple times.
Note
If [LIST] has multiple arguments, then you have to put these in quotes. For example:
# dracut --force-add "module1 module2" ...
-d, --drivers <list of kernel modules>
specify a space-separated list of kernel modules to exclusively include in the initramfs. The kernel modules have to be specified
without the ".ko" suffix. This parameter can be specified multiple times.
Note
If [LIST] has multiple arguments, then you have to put these in quotes. For example:
# dracut --drivers "kmodule1 kmodule2" ...
--add-drivers <list of kernel modules>
specify a space-separated list of kernel modules to add to the initramfs. The kernel modules have to be specified without the ".ko"
suffix. This parameter can be specified multiple times.
Note
If [LIST] has multiple arguments, then you have to put these in quotes. For example:
# dracut --add-drivers "kmodule1 kmodule2" ...
--omit-drivers <list of kernel modules>
specify a space-separated list of kernel modules not to add to the initramfs. The kernel modules have to be specified without the ".ko"
suffix. This parameter can be specified multiple times.
Note
If [LIST] has multiple arguments, then you have to put these in quotes. For example:
# dracut --omit-drivers "kmodule1 kmodule2" ...
--filesystems <list of filesystems>
specify a space-separated list of kernel filesystem modules to exclusively include in the generic initramfs. This parameter can be
specified multiple times.
Note
If [LIST] has multiple arguments, then you have to put these in quotes. For example:
# dracut --filesystems "filesystem1 filesystem2" ...
-k, --kmoddir <kernel directory>
specify the directory, where to look for kernel modules
--fwdir <dir>[:<dir>...]++
specify additional directories, where to look for firmwares. This parameter can be specified multiple times.
--kernel-only
only install kernel drivers and firmware files
--no-kernel
do not install kernel drivers and firmware files
--mdadmconf
include local /etc/mdadm.conf
--nomdadmconf
do not include local /etc/mdadm.conf
--lvmconf
include local /etc/lvm/lvm.conf
--nolvmconf
do not include local /etc/lvm/lvm.conf
--fscks [LIST]
add a space-separated list of fsck tools, in addition to dracut.conf's specification; the installation is opportunistic (non-existing
tools are ignored)
Note
If [LIST] has multiple arguments, then you have to put these in quotes. For example:
# dracut --fscks "fsck.foo barfsck" ...
--nofscks
inhibit installation of any fsck tools
--strip
strip binaries in the initramfs (default)
--nostrip
do not strip binaries in the initramfs
--prefix <dir>
prefix initramfs files with the specified directory
--noprefix
do not prefix initramfs files (default)
-h, --help
display help text and exit.
--debug
output debug information of the build process
-v, --verbose
increase verbosity level (default is info(4))
-q, --quiet
decrease verbosity level (default is info(4))
-c, --conf <dracut configuration file>
specify configuration file to use.
Default: /etc/dracut.conf
--confdir <configuration directory>
specify configuration directory to use.
Default: /etc/dracut.conf.d
--tmpdir <temporary directory>
specify temporary directory to use.
Default: /var/tmp
--sshkey <sshkey file>
ssh key file used with ssh-client module.
-l, --local
activates the local mode. dracut will use modules from the current working directory instead of the system-wide installed modules in
/usr/lib/dracut/modules.d. This is useful when running dracut from a git checkout.
-H, --hostonly
Host-Only mode: Install only what is needed for booting the local host instead of a generic host and generate host-specific
configuration.
Warning
If chrooted to another root other than the real root device, use "--fstab" and provide a valid /etc/fstab.
--no-hostonly
Disable Host-Only mode
--fstab
Use /etc/fstab instead of /proc/self/mountinfo.
--add-fstab _<filename>_
Add entries of <filename> to the initramfs /etc/fstab.
--mount "<device> <mountpoint> <filesystem type> <filesystem options>"
Mount <device> on <mountpoint> with <filesystem type> and <filesystem options> in the initramfs
-i, --include <SOURCE>_ _<TARGET>
include the files in the SOURCE directory into the TARGET directory in the final initramfs. If SOURCE is a file, it will be installed
to TARGET in the final initramfs. This parameter can be specified multiple times.
-I, --install <file list>
install the space separated list of files into the initramfs.
Note
If [LIST] has multiple arguments, then you have to put these in quotes. For example:
+
# dracut --install "/bin/foo /sbin/bar" ...
--gzip
Compress the generated initramfs using gzip. This will be done by default, unless another compression option or --no-compress is
passed. Equivalent to "--compress=gzip -9"
--bzip2
Compress the generated initramfs using bzip2.
Warning
Make sure your kernel has bzip2 decompression support compiled in, otherwise you will not be able to boot. Equivalent to
"--compress=bzip2"
--lzma
Compress the generated initramfs using lzma.
Warning
Make sure your kernel has lzma decompression support compiled in, otherwise you will not be able to boot. Equivalent to
"--compress=lzma -9"
--xz
Compress the generated initramfs using xz.
Warning
Make sure your kernel has xz decompression support compiled in, otherwise you will not be able to boot. Equivalent to
"--compress=xz --check=crc32 --lzma2=dict=1MiB"
--compress <compressor>
Compress the generated initramfs using the passed compression program. If you pass it just the name of a compression program, it will
call that program with known-working arguments. If you pass a quoted string with arguments, it will be called with exactly those
arguments. Depending on what you pass, this may result in an initramfs that the kernel cannot decompress.
--no-compress
Do not compress the generated initramfs. This will override any other compression options.
--list-modules
List all available dracut modules.
-M, --show-modules
Print included module's name to standard output during build.
--keep
Keep the initramfs temporary directory for debugging purposes.
FILES
/var/log/dracut.log
logfile of initramfs image creation
/tmp/dracut.log
logfile of initramfs image creation, if /var/log/dracut.log is not writable
/etc/dracut.conf
see dracut.conf5
/etc/dracut.conf.d/*.conf
see dracut.conf5
Configuration in the initramfs
/etc/conf.d/
Any files found in /etc/conf.d/ will be sourced in the initramfs to set initial values. Command line options will override these values
set in the configuration files.
/etc/cmdline
Can contain additional command line options.
AVAILABILITY
The dracut command is part of the dracut package and is available from https://dracut.wiki.kernel.org
AUTHORS
Harald Hoyer
Project Leader and Developer
Victor Lowther
Developer
Philippe Seewer
Developer
Warren Togami
Developer
Amadeusz olnowski
Developer
Jeremy Katz
Developer
David Dillow
Developer
Will Woods
Developer
SEE ALSO
dracut.cmdline(7) dracut.conf(5)
dracut 11/08/2012 DRACUT(8)