NAME
----
-dracut - low-level tool for generating an initramfs image
+dracut - low-level tool for generating an initramfs/initrd image
SYNOPSIS
--------
as initial root file system. All finding of the root device happens in this
early userspace.
+Initramfs images are also called "initrd".
+
For a complete list of kernel command line options see *dracut.cmdline*(7).
If you are dropped to an emergency shell, while booting your initramfs,
**-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.
+**-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 --modules "module1 module2" ...
+# dracut --add "module1 module2" ...
----
===============================
-**-o, --omit** _<list of dracut modules>_::
- omit a space-separated list of dracut modules. This parameter can be
- specified multiple times.
+**--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 --omit "module1 module2" ...
+# dracut --force-add "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.
+**-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 --add "module1 module2" ...
+# dracut --omit "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.
+**-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.
+ This option forces dracut to only include the specified dracut modules.
+ In most cases the "--add" option is what you want to use.
+
[NOTE]
===============================
If [LIST] has multiple arguments, then you have to put these in quotes. For
example:
----
-# dracut --force-add "module1 module2" ...
+# dracut --modules "module1 module2" ...
----
===============================
**--nostrip**::
do not strip binaries in the initramfs
-**--prelink**::
- prelink binaries in the initramfs (default)
-
-**--noprelink**::
- do not prelink binaries in the initramfs
-
**--hardlink**::
hardlink files in the initramfs (default)
**--no-hostonly-cmdline**:
Do not store kernel command line arguments needed in the initramfs
+**--no-hostonly-default-device**:
+ Do not generate implicit host devices like root, swap, fstab, etc.
+ Use "--mount" or "--add-device" to explicitly add devices as needed.
+
+**--hostonly-i18n**:
+ Install only needed keyboard and font files according to the host configuration (default).
+
+**--no-hostonly-i18n**:
+ Install all keyboard and font files available.
+
**--persistent-policy** _<policy>_::
Use _<policy>_ to address disks and partitions.
_<policy>_ can be any directory name found in /dev/disk.
The default _<dump frequency>_ is "0".
the default _<fsck order>_ is "2".
+**--mount** "_<mountpoint>_"::
+ Like above, but _<device>_, _<filesystem type>_ and _<filesystem options>_
+ are determined by looking at the current mounts.
+
**--add-device** _<device>_ ::
Bring up _<device>_ in initramfs, _<device>_ should be the device name.
This can be useful in hostonly mode for resume support when your swap is on
will not be able to boot.
====
+**--zstd**::
+ Compress the generated initramfs using Zstandard.
+[WARNING]
+====
+Make sure your kernel has zstd decompression support compiled in, otherwise you
+will not be able to boot.
+====
+
**--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.
+ The default value can also be set via the _INITRD_COMPRESS_ environment variable.
**--no-compress**::
Do not compress the generated initramfs. This will override any other
**--reproducible**::
Create reproducible images.
+**--no-reproducible**::
+ Do not create reproducible images.
+
**--list-modules**::
List all available dracut modules.
**--uefi**::
Instead of creating an initramfs image, dracut will create an UEFI executable,
- which can be executed by an UEFI BIOS.
+ which can be executed by an UEFI BIOS. 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-existant or empty.
+
+**--no-machineid**::
+ affects the default output filename of **--uefi** and will discard the <MACHINE_ID>
+ part.
**--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_
- or _/usr/lib/gummiboot/linux<EFI-MACHINE-TYPE-NAME>.efi.stub_
+ _$prefix/lib/systemd/boot/efi/linux<EFI-MACHINE-TYPE-NAME>.efi.stub_
+ or _$prefix/lib/gummiboot/linux<EFI-MACHINE-TYPE-NAME>.efi.stub_
**--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>_
+ENVIRONMENT
+-----------
+
+_INITRD_COMPRESS_::
+ sets the default compression program. See **--compress**.
+
FILES
-----
_/var/log/dracut.log_::