DESCRIPTION
-----------
+
+Create an initramfs <image> for the kernel with the version <kernel version>.
+If <kernel version> is omitted, then the version of the actual running
+kernel is used. If <image> is omitted or empty, then the default location
+/boot/initramfs-<kernel version>.img is used.
+
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.
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)
+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,
+the file _/run/initramfs/rdsosreport.txt_ is created, which can be safed to a
+(to be mounted by hand) partition (usually /boot) or a USB stick.
+Additional debugging info can be produced by adding **rd.debug** to the kernel command line.
+_/run/initramfs/rdsosreport.txt_ contains all logs and the output of some tools.
+It should be attached to any report about dracut problems.
+
+EXAMPLE
+-------
+
+To create a initramfs image, the most simple command is:
+----
+# dracut
+----
+
+This will generate a general purpose initramfs image, with all possible
+functionality resulting of the combination of the installed dracut modules and
+system tools. The image is /boot/initramfs-_++<kernel version>++_.img and
+contains the kernel modules of the currently active kernel with version
+_++<kernel version>++_.
+
+If the initramfs image already exists, dracut will display an error message, and
+to overwrite the existing image, you have to use the --force option.
+----
+# dracut --force
+----
+
+If you want to specify another filename for the resulting image you would issue
+a command like:
+----
+# dracut foobar.img
+----
+
+To generate an image for a specific kernel version, the command would be:
+----
+# dracut foobar.img 2.6.40-1.rc5.f20
+----
+
+A shortcut to generate the image at the default location for a specific kernel
+version is:
+----
+# dracut --kver 2.6.40-1.rc5.f20
+----
+
+If you want to create lighter, smaller initramfs images, you may want to specify
+the --hostonly or -H option. Using this option, the resulting image will
+contain only those dracut modules, kernel modules and filesystems, which are
+needed to boot this specific machine. This has the drawback, that you can't put
+the disk on another controller or machine, and that you can't switch to another
+root filesystem, without recreating the initramfs image. The usage of the
+--hostonly option is only for experts and you will have to keep the broken
+pieces. At least keep a copy of a general purpose image (and corresponding
+kernel) as a fallback to rescue your system.
+
OPTIONS
-------
specify additional directories, where to look for firmwares. This parameter
can be specified multiple times.
+**--kernel-cmdline <parameters>**::
+ specify default kernel command line parameters
+
+
**--kernel-only**::
only install kernel drivers and firmware files
**--no-kernel**::
do not install kernel drivers and firmware files
+**--early-microcode**::
+ Combine early microcode with ramdisk
+
+**--no-early-microcode**::
+ Do not combine early microcode with ramdisk
+
+**--print-cmdline**::
+ print the kernel command line for the current disk layout
+
**--mdadmconf**::
include local _/etc/mdadm.conf_
inhibit installation of any fsck tools
**--strip**::
- strip binaries in the initramfs
+ strip binaries in the initramfs (default)
**--nostrip**::
- do not strip binaries in the initramfs (default)
+ do not strip binaries in the initramfs
**--hardlink**::
hardlink files in the initramfs (default)
provide a valid _/etc/fstab_.
====
-**--no-hostonly**::
+**-N, --no-hostonly**::
Disable Host-Only mode
+**--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"
+
**--fstab**::
Use _/etc/fstab_ instead of _/proc/self/mountinfo_.
Mount _<device>_ on _<mountpoint>_ with _<filesystem type>_ and _<filesystem
options>_ in the initramfs
+**--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
+ LVM or an encrypted partition.
+ [NB --device can be used for compatibility with earlier releases]
+
**-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
[WARNING]
====
Make sure your kernel has lzma decompression support compiled in, otherwise you
-will not be able to boot. Equivalent to "--compress=lzma -9"
+will not be able to boot. Equivalent to "lzma --compress=lzma -9"
====
**--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"
+will not be able to boot. Equivalent to "lzma --compress=xz --check=crc32 --lzma2=dict=1MiB"
====
**--compress** _<compressor>_::
**--keep**::
Keep the initramfs temporary directory for debugging purposes.
+**--printsize**::
+ Print out the module install size
+
+**--profile**:
+ Output profile information of the build process
+
+**--ro-mnt**:
+ Mount / and /usr read-only by default.
+
+**-L, --stdlog** _<level>_::
+ [0-6] Specify logging level (to standard error)
+----
+ 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)
+----
+
+**--regenerate-all**::
+ Regenerate all initramfs images at the default location with the kernel versions found on the system.
+ Additional parameters are passed through.
+
FILES
-----
_/var/log/dracut.log_::
_/etc/dracut.conf.d/*.conf_::
see dracut.conf5
+_/usr/lib/dracut/dracut.conf.d/*.conf_::
+ see dracut.conf5
+
Configuration in the initramfs
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
_/etc/conf.d/_::
set in the configuration files.
_/etc/cmdline_::
+ Can contain additional command line options. Deprecated, better use /etc/cmdline.d/*.conf.
+
+_/etc/cmdline.d/*.conf::
Can contain additional command line options.
AVAILABILITY
projects / platform / upstream / dracut.git / blobdiff