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.

        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 Żołnowski
    Developer

Jeremy Katz
    Developer

David Dillow
    Developer

Will Woods
    Developer

SEE ALSO

dracut.cmdline(7) dracut.conf(5)