dracut.conf(5) — Linux manual page


DRACUT.CONF(5)                   dracut                   DRACUT.CONF(5)

NAME         top

       dracut.conf - configuration file(s) for dracut

SYNOPSIS         top

       /etc/dracut.conf /etc/dracut.conf.d/*.conf

DESCRIPTION         top

       dracut.conf is loaded during the initialisation phase of dracut.
       Command line parameter will override any values set here.

       *.conf files are read from /usr/lib/dracut/dracut.conf.d and
       /etc/dracut.conf.d. Files with the same name in
       /etc/dracut.conf.d will replace files in
       /usr/lib/dracut/dracut.conf.d. The files are then read in
       alphanumerical order and will override parameters set in
       /etc/dracut.conf. Each line specifies an attribute and a value. A
       # indicates the beginning of a comment; following characters, up
       to the end of the line are not interpreted.

       dracut command line options will override any values set here.

       Configuration files must have the extension .conf; other
       extensions are ignored.

       add_dracutmodules+=" <dracut modules> "
           Add a space-separated list of dracut modules to call when
           building the initramfs. Modules are located in

       force_add_dracutmodules+=" <dracut modules> "
           Force to add a space-separated list of dracut modules to the
           default set of modules, when host-only mode is specified.
           This parameter can be specified multiple times.

       omit_dracutmodules+=" <dracut modules> "
           Omit a space-separated list of dracut modules to call when
           building the initramfs. Modules are located in

       dracutmodules+=" <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 option forces dracut to only
           include the specified dracut modules. In most cases the
           "add_dracutmodules" option is what you want to use.

       add_drivers+=" <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.

       force_drivers+=" <list of kernel modules> "
           See add_drivers above. But in this case it is ensured that
           the drivers are tried to be loaded early via modprobe.

       omit_drivers+=" <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.

       drivers+=" <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.

       filesystems+=" <filesystem names> "
           Specify a space-separated list of kernel filesystem modules
           to exclusively include in the generic initramfs.

       drivers_dir="<kernel modules directory>"
           Specify the directory where to look for kernel modules.

       fw_dir+=" :<dir>[:<dir> ...] "
           Specify additional colon-separated list of directories where
           to look for firmware files.

       libdirs+=" <dir>[ <dir> ...] "
           Specify a space-separated list of directories where to look
           for libraries.

       install_items+=" <file>[ <file> ...] "
           Specify additional files to include in the initramfs,
           separated by spaces.

       install_optional_items+=" <file>[ <file> ...] "
           Specify additional files to include in the initramfs,
           separated by spaces, if they exist.

       compress="{cat|bzip2|lzma|xz|gzip|lzop|lz4|zstd|<compressor [args
           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 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. To
           disable compression, use "cat".

       squash_compress="{<compressor [args ...]>}"
           Compress the squashfs image using the passed compressor and
           compressor specific options for mksquashfs. You can refer to
           mksquashfs manual for supported compressors and compressor
           specific options. If squash module is not called when
           building the initramfs, this option will not take effect.

           Strip binaries in the initramfs (default=yes).

           Strip more than just debug symbol and sections, for a smaller
           initramfs build. The "do_strip=yes" option must also be
           specified (default=no).

           Hardlink files in the initramfs (default=yes).

       prefix=" <directory> "
           Prefix initramfs files with <directory>.

           Host-only mode: Install only what is needed for booting the
           local host instead of a generic host and generate
           host-specific configuration (default=no).

           Specify the host-only mode to use (default=sloppy). In
           "sloppy" host-only mode, extra drivers and modules will be
           installed, so minor hardware change won’t make the image
           unbootable (e.g. changed keyboard), and the image is still
           portable among similar hosts. With "strict" mode enabled,
           anything not necessary for booting the local host in its
           current state will not be included, and modules may do some
           extra job to save more space. Minor change of hardware or
           environment could make the image unbootable.

           If set to "yes", store the kernel command line arguments
           needed in the initramfs. If hostonly="yes" and this option is
           not configured, it’s automatically set to "yes".

       hostonly_nics+=" [<nic>[ <nic> ...]] "
           Only enable listed NICs in the initramfs. The list can be
           empty, so other modules can install only the necessary
           network drivers.

           Use <policy> to address disks and partitions.  <policy> can
           be any directory name found in /dev/disk (e.g. "by-uuid",
           "by-label"), or "mapper" to use /dev/mapper device names

       tmpdir="<temporary directory>"
           Specify temporary directory to use.


           If chrooted to another root other than the real root device,
           use --fstab and provide a valid /etc/fstab.

           Use /etc/fstab instead of /proc/self/mountinfo (default=no).

       add_fstab+=" <filename> "
           Add entries of <filename> to the initramfs /etc/fstab.

       add_device+=" <device> "
           Bring up <device> in initramfs, <device> should be the device
           name. This can be useful in host-only mode for resume support
           when your swap is on LVM an encrypted partition.

           Include local /etc/mdadm.conf (default=no).

           Include local /etc/lvm/lvm.conf (default=no).

       fscks=" <fsck tools> "
           Add a space-separated list of fsck tools. If nothing is
           specified, the default is: "umount mount /sbin/fsck* xfs_db
           xfs_check xfs_repair e2fsck jfs_fsck reiserfsck btrfsck". The
           installation is opportunistic (non-existing tools are

           If specified, inhibit installation of any fsck tools

           Mount / and /usr read-only by default (default=no).

           Specify default kernel command line parameters.

           Only install kernel drivers and firmware files (default=no).

           Do not install kernel drivers and firmware files


           Override BIOS provided ACPI tables. For further documentation
           read Documentation/acpi/initrd_table_override.txt in the
           kernel sources. Search for ACPI table files (must have .aml
           suffix) in acpi_table_dir= directory (see below) and add them
           to a separate uncompressed cpio archive. This cpio archive
           gets glued (concatenated, uncompressed one must be the first
           one) to the compressed cpio archive. The first, uncompressed
           cpio archive is for data which the kernel must be able to
           access very early (and cannot make use of uncompress
           algorithms yet) like microcode or ACPI tables (default=no).

           Directory to search for ACPI tables if acpi_override= is set
           to yes.

           Combine early microcode with ramdisk (default=yes).

           Specify logging level for standard error (default=4).


           Logging levels:

                   0 - suppress any messages
                   1 - only fatal errors
                   2 - all errors
                   3 - warnings
                   4 - info
                   5 - debug info (here starts lots of output)
                   6 - trace info (and even more)

           Specify logging level for syslog (default=0).

           Specify logging level for logfile (default=4).

           Path to logfile.

           SSH key file used with ssh-client module.

           Print the name of the included modules to standard output
           during build (default=no).

       i18n_vars="<variable mapping>"
           Distribution specific variable mapping. See
           dracut/modules.d/10i18n/README for a detailed description.

           The font <fontname> to install, if not specified otherwise.
           Default is "eurlatgr".

           Install everything regardless of generic or host-only mode

           Create reproducible images (default=no).

           Do not create an image in host-only mode, if no kernel driver
           is needed and no /etc/cmdline/*.conf will be generated into
           the initramfs (default=no).

           Log all files installed from the host to <directory>.

           Instead of creating an initramfs image, dracut will create an
           UEFI executable, which can be executed by an UEFI BIOS
           (default=no). The default output filename is
           <EFI> might be /efi, /boot or /boot/efi depending on where
           the ESP partition is mounted. The <BUILD_ID> is taken from
           BUILD_ID in /usr/lib/os-release or if it exists
           /etc/os-release and is left out, if BUILD_ID is non-existent
           or empty.

           Affects the default output filename of the UEFI executable,
           including the <MACHINE_ID> part (default=yes).

           Specifies the UEFI stub loader, which will load the attached
           kernel, initramfs and kernel command line and boots the
           kernel. The default is

           Specifies the UEFI stub loader’s splash image. Requires
           bitmap (.bmp) image format.

       uefi_secureboot_cert="<file>", uefi_secureboot_key="<file>"
           Specifies a certificate and corresponding key, which are used
           to sign the created UEFI executable. Requires both
           certificate and key need to be specified and sbsign to be

           Specifies an engine to use when signing the created UEFI
           executable. E.g. "pkcs11"

           Specifies the kernel image, which to include in the UEFI
           executable. The default is
           /lib/modules/<KERNEL-VERSION>/vmlinuz or

           Specifies the SBAT parameters, which to include in the UEFI
           executable. By default the default SBAT string added is
           "sbat,1,SBAT Version,sbat,1,
           https://github.com/rhboot/shim/blob/main/SBAT.md ".

           Attempt to use the dracut-cpio binary, which optimizes
           archive creation for copy-on-write filesystems (default=no).
           When specified, initramfs archives are also padded to ensure
           optimal data alignment for extent sharing. To retain reflink
           data deduplication benefits, this should be used alongside
           the compress="cat" and do_strip="no" parameters, with
           initramfs source files, tmpdir staging area and destination
           all on the same copy-on-write capable filesystem.

           If set to yes, try to execute tasks in parallel (currently
           only supported for --regenerate-all).

FILES         top

           Old configuration file. You better use your own file in

           Any /etc/dracut.conf.d/*.conf file can override the values in
           /etc/dracut.conf. The configuration files are read in
           alphanumerical order.

AUTHOR         top

       Harald Hoyer

SEE ALSO         top

       dracut(8) dracut.cmdline(7)

COLOPHON         top

       This page is part of the dracut (event driven initramfs
       infrastructure) project.  Information about the project can be
       found at ⟨https://dracut.wiki.kernel.org/index.php/Main_Page⟩.
       If you have a bug report for this manual page, send it to
       initramfs@vger.kernel.org.  This page was obtained from the
       project's upstream Git repository
       ⟨https://github.com/dracutdevs/dracut.git⟩ on 2024-06-14.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2024-03-21.)  If you discover any rendering
       problems in this HTML version of the page, or you believe there
       is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

dracut 059-204-g6acfecae       09/13/2023                 DRACUT.CONF(5)

Pages that refer to this page: dracut.cmdline(7)dracut(8)