add_dracutmodules+=" <dracut
modules> "
Add a space-separated list of dracut modules to call when
building the initramfs. Modules are located in
/usr/lib/dracut/modules.d.
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
/usr/lib/dracut/modules.d.
Warning
Avoid manually omitting dracut modules, as you may inadvertently remove
essential ones that dracut can’t detect or warn you about. Using this
option is not recommended and is at your own risk.
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. This option is not recommended to use (use at
your own risk).
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. This option forces dracut to only include
the specified kernel modules. In most cases the "--add-drivers"
option is what you want to use. This option is not recommended to use (use at
your own risk).
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.
do_strip="{yes|no}"
Strip binaries in the initramfs (default=yes).
aggressive_strip="{yes|no}"
Strip more than just debug symbol and sections, for a
smaller initramfs build. The "do_strip=yes" option must also be
specified (default=no).
do_hardlink="{yes|no}"
Hardlink files in the initramfs (default=yes).
prefix=" <directory> "
Prefix initramfs files with
<directory>.
hostonly="{yes|no}"
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).
hostonly_mode="{sloppy|strict}"
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 make additional efforts to save more space. Minor changes in
hardware or environment can make the image unbootable.
hostonly_cmdline="{yes|no}"
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.
persistent_policy="<policy>"
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 (default=mapper).
tmpdir="<temporary directory>"
Specify temporary directory to use.
Warning
If chrooted to another root other than the real root device, use --fstab and
provide a valid
/etc/fstab.
use_fstab="{yes|no}"
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.
mdadmconf="{yes|no}"
Include local /etc/mdadm.conf (default=no).
lvmconf="{yes|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 btrfsck.
The installation is opportunistic (non-existing tools are
ignored).
nofscks="{yes|no}"
If specified, inhibit installation of any fsck tools
(default=no).
ro_mnt="{yes|no}"
Mount / and /usr read-only by default
(default=no).
kernel_cmdline="parameters"
Specify default kernel command line parameters. Despite
its name, this command only sets initrd parameters.
kernel_only="{yes|no}"
Only install kernel drivers and firmware files
(default=no).
no_kernel="{yes|no}"
Do not install kernel drivers and firmware files
(default=no).
acpi_override="{yes|no}"
Caution
Only use this if you know what you are doing!
Override BIOS provided ACPI tables. For further documentation read
Documentation/acpi/initrd_table_override.txt[1] 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).
acpi_table_dir="<dir>"
Directory to search for ACPI tables if acpi_override= is
set to yes.
early_microcode="{yes|no}"
Combine early microcode with ramdisk (default=yes).
stdloglvl="{0-6}"
Specify logging level for standard error (default=4).
Table 1. 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) |
sysloglvl="{0-6}"
Specify logging level for syslog (default=0).
fileloglvl="{0-6}"
Specify logging level for logfile (default=4).
logfile="<file>"
Path to logfile.
sshkey="<file>"
SSH key file used with ssh-client module.
show_modules="{yes|no}"
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.
i18n_default_font="<fontname>"
The font <fontname> to install, if not specified
otherwise. Default is "eurlatgr".
i18n_install_all="{yes|no}"
Install everything regardless of generic or host-only
mode (default=no).
reproducible="{yes|no}"
Create reproducible images (default=no).
noimageifnotneeded="{yes|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).
loginstall="<directory>"
Log all files installed from the host to
<directory>.
uefi="{yes|no}"
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>/EFI/Linux/linux-$kernel$-<MACHINE_ID>-<BUILD_ID>.efi.
<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.
machine_id="{yes|no}"
Affects the default output filename of the UEFI
executable, including the <MACHINE_ID> part (default=yes).
uefi_stub="<file>"
Specifies the UEFI stub loader, which will load the
attached kernel, initramfs and kernel command line and boots the kernel. The
default is
/lib/systemd/boot/efi/linux<EFI-MACHINE-TYPE-NAME>.efi.stub.
uefi_splash_image="<file>"
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 installed.
uefi_secureboot_engine="parameter"
Specifies an engine to use when signing the created UEFI
executable. E.g. "pkcs11"
kernel_image="<file>"
Specifies the kernel image, which to include in the UEFI
executable. The default is /lib/modules/<KERNEL-VERSION>/vmlinuz
or /boot/vmlinuz-<KERNEL-VERSION>.
sbat="parameters"
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+.
enhanced_cpio="{yes|no}"
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 file-system.
parallel="{yes|no}"
If set to yes, try to execute tasks in parallel
(currently only supported for --regenerate-all).
initrdname="<filepattern>"
Specifies the file name for the generated initramfs if it
is not set otherwise.
The initrdname configuration option is required to match the
initr*${kernel}* file pattern and only one file with this pattern
should exists in the directory where initramfs is loaded from.
Defaults to initramfs-${kernel}.img.