Provided by: dracut-core_059-4ubuntu2_amd64 bug

NAME

       dracut - low-level tool for generating an initramfs/initrd image

SYNOPSIS

       dracut [OPTION...] [<image> [<kernel version>]]

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, depending on bootloader specification, the default location can be
       /efi/<machine-id>/<kernel-version>/initrd, /boot/<machine-id>/<kernel-version>/initrd,
       /boot/efi/<machine-id>/<kernel-version>/initrd, /lib/modules/<kernel-version>/initrd or
       /boot/initrd.img-<kernel-version>.

       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.

       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, the file
       /run/initramfs/rdsosreport.txt is created, which can be saved 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.

USAGE

       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,
       depending on bootloader specification, can be /efi/<machine-id>/<kernel-version>/initrd,
       /boot/<machine-id>/<kernel-version>/initrd,
       /boot/efi/<machine-id>/<kernel-version>/initrd, /lib/modules/<kernel-version>/initrd or
       /boot/initrd.img-<kernel-version>_ 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.

   Inspecting the Contents
       To see the contents of the image created by dracut, you can use the lsinitrd tool.

           # lsinitrd | less

       To display the contents of a file in the initramfs also use the lsinitrd tool:

           # lsinitrd -f /etc/ld.so.conf
           include ld.so.conf.d/*.conf

   Adding dracut Modules
       Some dracut modules are turned off by default and have to be activated manually. You can
       do this by adding the dracut modules to the configuration file /etc/dracut.conf or
       /etc/dracut.conf.d/myconf.conf. See dracut.conf(5). You can also add dracut modules on the
       command line by using the -a or --add option:

           # dracut --add module initramfs-module.img

       To see a list of available dracut modules, use the --list-modules option:

           # dracut --list-modules

   Omitting dracut Modules
       Sometimes you don’t want a dracut module to be included for reasons of speed, size or
       functionality. To do this, either specify the omit_dracutmodules variable in the
       dracut.conf or /etc/dracut.conf.d/myconf.conf configuration file (see dracut.conf(5)), or
       use the -o or --omit option on the command line:

           # dracut -o "multipath lvm" no-multipath-lvm.img

   Adding Kernel Modules
       If you need a special kernel module in the initramfs, which is not automatically picked up
       by dracut, you have the use the --add-drivers option on the command line or the drivers
       variable in the /etc/dracut.conf or /etc/dracut.conf.d/myconf.conf configuration file (see
       dracut.conf(5)):

           # dracut --add-drivers mymod initramfs-with-mymod.img

   Boot parameters
       An initramfs generated without the "hostonly" mode, does not contain any system
       configuration files (except for some special exceptions), so the configuration has to be
       done on the kernel command line. With this flexibility, you can easily boot from a changed
       root partition, without the need to recompile the initramfs image. So, you could
       completely change your root partition (move it inside a md raid with encryption and LVM on
       top), as long as you specify the correct filesystem LABEL or UUID on the kernel command
       line for your root device, dracut will find it and boot from it.

       The kernel command line can also be provided by the dhcp server with the root-path option.
       See the section called “Network Boot”.

       For a full reference of all kernel command line parameters, see dracut.cmdline(7).

       To get a quick start for the suitable kernel command line on your system, use the
       --print-cmdline option:

           # dracut --print-cmdline
            root=UUID=8b8b6f91-95c7-4da2-831b-171e12179081 rootflags=rw,relatime,discard,data=ordered rootfstype=ext4

       Specifying the root Device
           This is the only option dracut really needs to boot from your root partition. Because
           your root partition can live in various environments, there are a lot of formats for
           the root= option. The most basic one is root=<path to device node>:

               root=/dev/sda2

           Because device node names can change, dependent on the drive ordering, you are
           encouraged to use the filesystem identifier (UUID) or filesystem label (LABEL) to
           specify your root partition:

               root=UUID=19e9dda3-5a38-484d-a9b0-fa6b067d0331

           or

               root=LABEL=myrootpartitionlabel

           To see all UUIDs or LABELs on your system, do:

               # ls -l /dev/disk/by-uuid

           or

               # ls -l /dev/disk/by-label

           If your root partition is on the network see the section called “Network Boot”.

       Keyboard Settings
           If you have to input passwords for encrypted disk volumes, you might want to set the
           keyboard layout and specify a display font.

           A typical german kernel command line would contain:

               rd.vconsole.font=eurlatgr rd.vconsole.keymap=de-latin1-nodeadkeys rd.locale.LANG=de_DE.UTF-8

           Setting these options can override the setting stored on your system, if you use a
           modern init system, like systemd.

       Blacklisting Kernel Modules
           Sometimes it is required to prevent the automatic kernel module loading of a specific
           kernel module. To do this, just add rd.driver.blacklist=<kernel module name>, with
           <kernel module name> not containing the .ko suffix, to the kernel command line. For
           example:

               rd.driver.blacklist=mptsas rd.driver.blacklist=nouveau

           The option can be specified multiple times on the kernel command line.

       Speeding up the Boot Process
           If you want to speed up the boot process, you can specify as much information for
           dracut on the kernel command as possible. For example, you can tell dracut, that you
           root partition is not on a LVM volume or not on a raid partition, or that it lives
           inside a specific crypto LUKS encrypted volume. By default, dracut searches
           everywhere. A typical dracut kernel command line for a plain primary or logical
           partition would contain:

               rd.luks=0 rd.lvm=0 rd.md=0 rd.dm=0

           This turns off every automatic assembly of LVM, MD raids, DM raids and crypto LUKS.

           Of course, you could also omit the dracut modules in the initramfs creation process,
           but then you would lose the possibility to turn it on on demand.

   Injecting custom Files
       To add your own files to the initramfs image, you have several possibilities.

       The --include option let you specify a source path and a target path. For example

           # dracut --include cmdline-preset /etc/cmdline.d/mycmdline.conf initramfs-cmdline-pre.img

       will create an initramfs image, where the file cmdline-preset will be copied inside the
       initramfs to /etc/cmdline.d/mycmdline.conf. --include can only be specified once.

           # mkdir -p rd.live.overlay/etc/cmdline.d
           # mkdir -p rd.live.overlay/etc/conf.d
           # echo "ip=dhcp" >> rd.live.overlay/etc/cmdline.d/mycmdline.conf
           # echo export FOO=testtest >> rd.live.overlay/etc/conf.d/testvar.conf
           # echo export BAR=testtest >> rd.live.overlay/etc/conf.d/testvar.conf
           # tree rd.live.overlay/
           rd.live.overlay/
           `-- etc
               |-- cmdline.d
               |   `-- mycmdline.conf
               `-- conf.d
                   `-- testvar.conf

           # dracut --include rd.live.overlay / initramfs-rd.live.overlay.img

       This will put the contents of the rd.live.overlay directory into the root of the initramfs
       image.

       The --install option let you specify several files, which will get installed in the
       initramfs image at the same location, as they are present on initramfs creation time.

           # dracut --install 'strace fsck.ext3 ssh' initramfs-dbg.img

       This will create an initramfs with the strace, fsck.ext3 and ssh executables, together
       with the libraries needed to start those. The --install option can be specified multiple
       times.

   Network Boot
       If your root partition is on a network drive, you have to have the network dracut modules
       installed to create a network aware initramfs image.

       If you specify ip=dhcp on the kernel command line, then dracut asks a dhcp server about
       the ip address for the machine. The dhcp server can also serve an additional root-path,
       which will set the root device for dracut. With this mechanism, you have static
       configuration on your client machine and a centralized boot configuration on your
       TFTP/DHCP server. If you can’t pass a kernel command line, then you can inject
       /etc/cmdline.d/mycmdline.conf, with a method described in the section called “Injecting
       custom Files”.

       Reducing the Image Size
           To reduce the size of the initramfs, you should create it with by omitting all dracut
           modules, which you know, you don’t need to boot the machine.

           You can also specify the exact dracut and kernel modules to produce a very tiny
           initramfs image.

           For example for a NFS image, you would do:

               # dracut -m "nfs network base" initramfs-nfs-only.img

           Then you would boot from this image with your target machine and reduce the size once
           more by creating it on the target machine with the --host-only option:

               # dracut -m "nfs network base" --host-only initramfs-nfs-host-only.img

           This will reduce the size of the initramfs image significantly.

TROUBLESHOOTING

       If the boot process does not succeed, you have several options to debug the situation.

   Identifying your problem area
        1. Remove 'rhgb' and 'quiet' from the kernel command line

        2. Add 'rd.shell' to the kernel command line. This will present a shell should dracut be
           unable to locate your root device

        3. Add 'rd.shell rd.debug log_buf_len=1M' to the kernel command line so that dracut shell
           commands are printed as they are executed

        4. The file /run/initramfs/rdsosreport.txt is generated, which contains all the logs and
           the output of all significant tools, which are mentioned later.

       If you want to save that output, simply mount /boot by hand or insert an USB stick and
       mount that. Then you can store the output for later inspection.

   Information to include in your report
       All bug reports
           In all cases, the following should be mentioned and attached to your bug report:

           •   The exact kernel command-line used. Typically from the bootloader configuration
               file (e.g.  /boot/grub2/grub.cfg) or from /proc/cmdline.

           •   A copy of your disk partition information from /etc/fstab, which might be obtained
               booting an old working initramfs or a rescue medium.

           •   Turn on dracut debugging (see the debugging dracut section), and attach the file
               /run/initramfs/rdsosreport.txt.

           •   If you use a dracut configuration file, please include /etc/dracut.conf and all
               files in /etc/dracut.conf.d/*.conf

       Network root device related problems
           This section details information to include when experiencing problems on a system
           whose root device is located on a network attached volume (e.g. iSCSI, NFS or NBD). As
           well as the information from the section called “All bug reports”, include the
           following information:

           •   Please include the output of

                   # /sbin/ifup <interfacename>
                   # ip addr show

   Debugging dracut
       Configure a serial console
           Successfully debugging dracut will require some form of console logging during the
           system boot. This section documents configuring a serial console connection to record
           boot messages.

            1. First, enable serial console output for both the kernel and the bootloader.

            2. Open the file /boot/grub2/grub.cfg for editing. Below the line 'timeout=5', add
               the following:

                   serial --unit=0 --speed=9600
                   terminal --timeout=5 serial console

            3. Also in /boot/grub2/grub.cfg, add the following boot arguments to the 'kernel'
               line:

                   console=tty0 console=ttyS0,9600

            4. When finished, the /boot/grub2/grub.cfg file should look similar to the example
               below.

                   default=0
                   timeout=5
                   serial --unit=0 --speed=9600
                   terminal --timeout=5 serial console
                   title Fedora (2.6.29.5-191.fc11.x86_64)
                     root (hd0,0)
                     kernel /vmlinuz-2.6.29.5-191.fc11.x86_64 ro root=/dev/mapper/vg_uc1-lv_root console=tty0 console=ttyS0,9600
                     initrd /dracut-2.6.29.5-191.fc11.x86_64.img

            5. More detailed information on how to configure the kernel for console output can be
               found at
               http://www.faqs.org/docs/Linux-HOWTO/Remote-Serial-Console-HOWTO.html#CONFIGURE-KERNEL.

            6. Redirecting non-interactive output

                   Note
                   You can redirect all non-interactive output to /dev/kmsg and the kernel will
                   put it out on the console when it reaches the kernel buffer by doing

                   # exec >/dev/kmsg 2>&1 </dev/console

       Using the dracut shell
           dracut offers a shell for interactive debugging in the event dracut fails to locate
           your root filesystem. To enable the shell:

            1. Add the boot parameter 'rd.shell' to your bootloader configuration file (e.g.
               /boot/grub2/grub.cfg)

            2. Remove the boot arguments 'rhgb' and 'quiet'

               A sample /boot/grub2/grub.cfg bootloader configuration file is listed below.

                   default=0
                   timeout=5
                   serial --unit=0 --speed=9600
                   terminal --timeout=5 serial console
                   title Fedora (2.6.29.5-191.fc11.x86_64)
                     root (hd0,0)
                     kernel /vmlinuz-2.6.29.5-191.fc11.x86_64 ro root=/dev/mapper/vg_uc1-lv_root console=tty0 rd.shell
                     initrd /dracut-2.6.29.5-191.fc11.x86_64.img

            3. If system boot fails, you will be dropped into a shell as seen in the example
               below.

                   No root device found
                   Dropping to debug shell.

                   #

            4. Use this shell prompt to gather the information requested above (see the section
               called “All bug reports”).

       Accessing the root volume from the dracut shell
           From the dracut debug shell, you can manually perform the task of locating and
           preparing your root volume for boot. The required steps will depend on how your root
           volume is configured. Common scenarios include:

           •   A block device (e.g.  /dev/sda7)

           •   A LVM logical volume (e.g.  /dev/VolGroup00/LogVol00)

           •   An encrypted device (e.g.  /dev/mapper/luks-4d5972ea-901c-4584-bd75-1da802417d83)

           •   A network attached device (e.g.
               netroot=iscsi:@192.168.0.4::3260::iqn.2009-02.org.example:for.all)

           The exact method for locating and preparing will vary. However, to continue with a
           successful boot, the objective is to locate your root volume and create a symlink
           /dev/root which points to the file system. For example, the following example
           demonstrates accessing and booting a root volume that is an encrypted LVM Logical
           volume.

            1. Inspect your partitions using parted

                   # parted /dev/sda -s p
                   Model: ATA HTS541060G9AT00 (scsi)
                   Disk /dev/sda: 60.0GB
                   Sector size (logical/physical): 512B/512B
                   Partition Table: msdos
                   Number  Start   End     Size    Type      File system  Flags
                   1      32.3kB  10.8GB  107MB   primary   ext4         boot
                   2      10.8GB  55.6GB  44.7GB  logical                lvm

            2. You recall that your root volume was a LVM logical volume. Scan and activate any
               logical volumes.

                   # lvm vgscan
                   # lvm vgchange -ay

            3. You should see any logical volumes now using the command blkid:

                   # blkid
                   /dev/sda1: UUID="3de247f3-5de4-4a44-afc5-1fe179750cf7" TYPE="ext4"
                   /dev/sda2: UUID="Ek4dQw-cOtq-5MJu-OGRF-xz5k-O2l8-wdDj0I" TYPE="LVM2_member"
                   /dev/mapper/linux-root: UUID="def0269e-424b-4752-acf3-1077bf96ad2c" TYPE="crypto_LUKS"
                   /dev/mapper/linux-home: UUID="c69127c1-f153-4ea2-b58e-4cbfa9257c5e" TYPE="ext3"
                   /dev/mapper/linux-swap: UUID="47b4d329-975c-4c08-b218-f9c9bf3635f1" TYPE="swap"

            4. From the output above, you recall that your root volume exists on an encrypted
               block device. Following the guidance disk encryption guidance from the
               Installation Guide, you unlock your encrypted root volume.

                   # UUID=$(cryptsetup luksUUID /dev/mapper/linux-root)
                   # cryptsetup luksOpen /dev/mapper/linux-root luks-$UUID
                   Enter passphrase for /dev/mapper/linux-root:
                   Key slot 0 unlocked.

            5. Next, make a symbolic link to the unlocked root volume

                   # ln -s /dev/mapper/luks-$UUID /dev/root

            6. With the root volume available, you may continue booting the system by exiting the
               dracut shell

                   # exit

       Additional dracut boot parameters
           For more debugging options, see dracut.cmdline(7).

       Debugging dracut on shutdown
           To debug the shutdown sequence on systemd systems, you can rd.break on pre-shutdown or
           shutdown.

           To do this from an already booted system:

               # mkdir -p /run/initramfs/etc/cmdline.d
               # echo "rd.debug rd.break=pre-shutdown rd.break=shutdown" > /run/initramfs/etc/cmdline.d/debug.conf
               # touch /run/initramfs/.need_shutdown

           This will give you a dracut shell after the system pivot’ed back in the initramfs.

OPTIONS

       --kver <kernel version>
           Set the kernel version. This enables to specify the kernel version, without specifying
           the location of the initramfs image. For example:

           # dracut --kver 3.5.0-0.rc7.git1.2.fc18.x86_64

       -f, --force
           Overwrite existing initramfs file.

       <output file> --rebuild
           Append the current arguments to those with which the input initramfs image was built.
           This option helps in incrementally building the initramfs for testing. If optional
           <output file> is not provided, the input initramfs provided to rebuild will be used as
           output file.

       -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 the 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 the list has multiple arguments, then you have to put these in quotes. For
               example:

                   # dracut --force-add "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 the list has multiple arguments, then you have to put these in quotes. For
               example:

                   # dracut --omit "module1 module2"  ...

       -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 the list has multiple arguments, then you have to put these in quotes. For
               example:

                   # dracut --modules "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 the 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 the list has multiple arguments, then you have to put these in quotes. For
               example:

                   # dracut --add-drivers "kmodule1 kmodule2"  ...

       --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.

               Note
               If the list has multiple arguments, then you have to put these in quotes. For
               example:

                   # dracut --force-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 the 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 the 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.

       --libdirs <list of directories>
           Specify a space-separated list of directories to look for libraries to include in the
           generic initramfs. This parameter can be specified multiple times.

               Note
               If the list has multiple arguments, then you have to put these in quotes. For
               example:

                   # dracut --libdirs "dir1 dir2"  ...

       --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 file.

       --nomdadmconf
           Do not include local /etc/mdadm.conf file.

       --lvmconf
           Include local /etc/lvm/lvm.conf file.

       --nolvmconf
           Do not include local /etc/lvm/lvm.conf file.

       --fscks <list of fsck tools>
           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 the 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).

       --aggressive-strip
           Strip more than just debug symbol and sections, for a smaller initramfs build. The
           --strip option must also be specified.

       --nostrip
           Do not strip binaries in the initramfs.

       --hardlink
           Hardlink files in the initramfs (default).

       --nohardlink
           Do not hardlink files 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)).

       --version
           Display version and exit.

       -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

       -r, --sysroot <sysroot directory>
           Specify the sysroot directory to collect files from. This is useful to create the
           initramfs image from a cross-compiled sysroot directory. For the extra helper
           variables, see ENVIRONMENT below.

           Default: empty

       --sshkey <sshkey file>
           SSH key file used with ssh-client module.

       --logfile <logfile>
           Logfile to use; overrides any setting from the configuration files.

           Default: /var/log/dracut.log

       -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 and generate host-specific configuration.

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

       -N, --no-hostonly
           Disable host-only mode.

       --hostonly-mode <mode>
           Specify the host-only mode to use.  <mode> could be one of "sloppy" or "strict". 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.

           Default: sloppy

       --hostonly-cmdline
           Store kernel command line arguments needed in the initramfs.

       --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.

       --hostonly-nics <list of nics>
           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).

       --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> [<dump frequency>
       [<fsck order>]]]"
           Mount <device> on <mountpoint> with <filesystem type> in the initramfs.  <filesystem
           options>, <dump options> and <fsck order> can be specified, see fstab manpage for the
           details. The default <filesystem options> is "defaults". 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 host-only 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 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 the list has multiple arguments, then you have to put these in quotes. For
               example:

                   # dracut --install "/bin/foo /sbin/bar"  ...

       --install-optional <file list>
           Install the space separated list of files into the initramfs, if they exist.

       --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 -9".

       --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 -T0".

       --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
               -T0".

       --lzo
           Compress the generated initramfs using lzop.

               Warning
               Make sure your kernel has lzo decompression support compiled in, otherwise you
               will not be able to boot. Equivalent to "--compress=lzop -9".

       --lz4
           Compress the generated initramfs using lz4.

               Warning
               Make sure your kernel has lz4 decompression support compiled in, otherwise you
               will not be able to boot. Equivalent to "--compress=lz4 -l -9".

       --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. Equivalent to "--compress=zstd -15 -q -T0".

       --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.

       --squash-compressor <compressor>
           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.

       --no-compress
           Do not compress the generated initramfs. This will override any other compression
           options.

       --reproducible
           Create reproducible images.

       --no-reproducible
           Do not create reproducible images.

       --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.

       --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.

       -p, --parallel
           Try to execute tasks in parallel. Currently only supported with --regenerate-all
           (build initramfs images for all kernel versions simultaneously).

       --noimageifnotneeded
           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.

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

       --uefi
           Instead of creating an initramfs image, dracut will create an UEFI executable, 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-uefi
           Disables UEFI mode.

       --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
           $prefix/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.

       --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>.

       --enhanced-cpio
           Attempt to use the dracut-cpio binary, which optimizes archive creation for
           copy-on-write filesystems by using the copy_file_range(2) syscall via Rust’s
           io::copy(). 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 --no-compress and --nostrip parameters, with initramfs
           source files, --tmpdir staging area and destination all on the same copy-on-write
           capable filesystem.

ENVIRONMENT

       INITRD_COMPRESS
           sets the default compression program. See --compress.

       DRACUT_LDCONFIG
           sets the ldconfig program path and options. Optional. Used for --sysroot.

           Default: ldconfig

       DRACUT_LDD
           sets the ldd program path and options. Optional. Used for --sysroot.

           Default: ldd

       DRACUT_TESTBIN
           sets the initially tested binary for detecting library paths. Optional. Used for
           --sysroot. In the cross-compiled sysroot, the default value (/bin/sh) is unusable, as
           it is an absolute symlink and points outside the sysroot directory.

           Default: /bin/sh

       DRACUT_INSTALL
           overrides path and options for executing dracut-install internally. Optional. Can be
           used to debug dracut-install while running the main dracut script.

           Default: dracut-install

           Example: DRACUT_INSTALL="valgrind dracut-install"

       DRACUT_COMPRESS_BZIP2, DRACUT_COMPRESS_BZIP2, DRACUT_COMPRESS_LBZIP2,
       DRACUT_COMPRESS_LZMA, DRACUT_COMPRESS_XZ, DRACUT_COMPRESS_GZIP, DRACUT_COMPRESS_PIGZ,
       DRACUT_COMPRESS_LZOP, DRACUT_COMPRESS_ZSTD, DRACUT_COMPRESS_LZ4, DRACUT_COMPRESS_CAT
           overrides for compression utilities to support using them from non-standard paths.

           Default values are the default compression utility names to be found in PATH.

       DRACUT_ARCH
           overrides the value of uname -m. Used for --sysroot.

           Default: empty (the value of uname -m on the host system)

       SYSTEMD_VERSION
           overrides systemd version. Used for --sysroot.

       SYSTEMCTL
           overrides the systemctl binary. Used for --sysroot.

       NM_VERSION
           overrides the NetworkManager version. Used for --sysroot.

       DRACUT_INSTALL_PATH
           overrides PATH environment for dracut-install to look for binaries relative to
           --sysroot. In a cross-compiled environment (e.g. Yocto), PATH points to natively built
           binaries that are not in the host’s /bin, /usr/bin, etc.  dracut-install still needs
           plain /bin and /usr/bin that are relative to the cross-compiled sysroot.

           Default: PATH

       DRACUT_INSTALL_LOG_TARGET
           overrides DRACUT_LOG_TARGET for dracut-install. It allows running dracut-install* to
           run with different log target that dracut** runs with.

           Default: DRACUT_LOG_TARGET

       DRACUT_INSTALL_LOG_LEVEL
           overrides DRACUT_LOG_LEVEL for dracut-install. It allows running dracut-install* to
           run with different log level that dracut** runs with.

           Default: DRACUT_LOG_LEVEL

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

       /usr/lib/dracut/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. Deprecated, better use
           /etc/cmdline.d/*.conf.

       /etc/cmdline.d/*.conf
           Can contain additional command line options.

AVAILABILITY

       The dracut command is part of the dracut package and is available from
       https://github.com/dracutdevs/dracut

AUTHORS

       Harald Hoyer

       Victor Lowther

       Amadeusz Żołnowski

       Hannes Reinecke

       Daniel Molkentin

       Will Woods

       Philippe Seewer

       Warren Togami

SEE ALSO

       dracut.cmdline(7) dracut.conf(5) lsinitrd(1)