DRACUT(8) dracut DRACUT(8) (NAME) dracut - initramfs/initrd (SYNOPSIS) dracut [...] [<> [< >]] (DESCRIPTION) <> initramfs < > . < > . <> . dracut ( IDE SCSI RAID) . RAM disk . . initramfs <> . man:dracut.cmdline[7] . initramfs /run/initramfs/rdsosreport.txt ( /boot) USB . rd.debug . /run/initramfs/rdsosreport.txt dracut . dracut root initramfs . dracut root . sulogin /etc/shadow root . (USAGE) initramfs : # dracut initramfs dracut . . . initramfs dracut --force . # dracut --force : # dracut foobar.img : # dracut foobar.img 2.6.40-1.rc5.f20 : # dracut --kver 2.6.40-1.rc5.f20 initramfs --hostonly -H . dracut . initramfs . ( ) . (INSPECTING THE CONTENTS) dracut lsinitrd . # lsinitrd | less initramfs lsinitrd : # lsinitrd -f /etc/ld.so.conf include ld.so.conf.d/*.conf DRACUT (ADDING DRACUT MODULES) dracut . dracut /etc/dracut.conf /etc/dracut.conf.d/myconf.conf . man:dracut.conf[5] . -a --add dracut : # dracut --add module initramfs-module.img dracut --list-modules : # dracut --list-modules (omitted) . --force-add host-only ( ). DRACUT (OMITTING DRACUT MODULES) dracut . omit_dracutmodules dracut.conf /etc/dracut.conf.d/myconf.conf (man:dracut.conf[5] ) -o --omit : # dracut -o "multipath lvm" no-multipath-lvm.img (ADDING KERNEL MODULES) initramfs dracut --add-drivers drivers /etc/dracut.conf /etc/dracut.conf.d/myconf.conf (man:dracut.conf[5] ): # dracut --add-drivers mymod initramfs-with-mymod.img (BOOT PARAMETERS) initramfs <> ( ) . initramfs . ( raid md LVM ) LABEL UUID dracut . /etc /var /run <> initramfs . /usr <> <> initramfs . /etc/fstab /etc/cryptab dracut <> . /etc/dracut.conf /etc/dracut.conf.d/ <> <> . ( --include) <>/<> . initrd ( ) . dhcp root-path . (NETWORK BOOT) . man:dracut.cmdline[7] . --print-cmdline : # dracut --print-cmdline root=UUID=8b8b6f91-95c7-4da2-831b-171e12179081 rootflags=rw,relatime,discard,data=ordered rootfstype=ext4 (Specifying the root Device) dracut . root= . root= : root=/dev/sda2 (UUID) (LABEL) : root=UUID=19e9dda3-5a38-484d-a9b0-fa6b067d0331 root=LABEL=myrootpartitionlabel UUID LABEL : # ls -l /dev/disk/by-uuid # ls -l /dev/disk/by-label (NETWORK BOOT) . (Keyboard Settings) . : rd.vconsole.font=eurlatgr rd.vconsole.keymap=de-latin1-nodeadkeys rd.locale.LANG=de_DE.UTF-8 init systemd . (Blacklisting Kernel Modules) . rd.driver.blacklist= ( .ko ) . : rd.driver.blacklist=mptsas rd.driver.blacklist=nouveau . (Speeding up the Boot Process) dracut . dracut LVM raid crypto LUKS . dracut . dracut : rd.luks=0 rd.lvm=0 rd.md=0 rd.dm=0 LVM MD raid DM raid crypto LUKS . dracut initramfs . (INJECTING CUSTOM FILES) initramfs . --include . : # dracut --include cmdline-preset /etc/cmdline.d/50-mycmdline.conf initramfs-cmdline-pre.img initramfs cmdline-preset initramfs /etc/cmdline.d/50-mycmdline.conf . # mkdir -p rd.overlay/etc/cmdline.d # mkdir -p rd.overlay/etc/conf.d # echo "ip=dhcp" >> rd.overlay/etc/cmdline.d/50-mycmdline.conf # echo export FOO=testtest >> rd.overlay/etc/conf.d/testvar.conf # echo export BAR=testtest >> rd.overlay/etc/conf.d/testvar.conf # tree rd.overlay/ rd.overlay/ `-- etc |-- cmdline.d | `-- 50-mycmdline.conf `-- conf.d `-- testvar.conf # dracut --include rd.overlay / initramfs-rd.overlay.img rd.overlay initramfs . --install initramfs initramfs . # dracut --install 'strace fsck.ext4 ssh' initramfs-dbg.img initramfs strace fsck.ext4 ssh . --install . (NETWORK BOOT) initramfs dracut . ip=dhcp dracut dhcp IP . dhcp root-path dracut . TFTP/DHCP . /etc/cmdline.d/50-mycmdline.conf (INJECTING CUSTOM FILES) . (Reducing the Image Size) initramfs dracut . dracut initramfs . NFS : # dracut -m "nfs network base" initramfs-nfs-only.img --host-only : # dracut -m "nfs network base" --host-only initramfs-nfs-host-only.img initramfs . (TROUBLESHOOTING) . (IDENTIFYING YOUR PROBLEM AREA) 1. 'splash' 'quiet' 2. 'rd.shell' . dracut 3. 'rd.shell rd.debug log_buf_len=1M' dracut 4. /run/initramfs/rdsosreport.txt . /boot USB . . (INFORMATION TO INCLUDE IN YOUR REPORT) (All bug reports) : o ( /boot/grub2/grub.cfg) /proc/cmdline. o /etc/fstab initramfs . o dracut ( dracut ) /run/initramfs/rdsosreport.txt . o dracut /etc/dracut.conf /etc/dracut.conf.d/*.conf . (Network root device related problems) ( iSCSI NFS NBD) . << >> : o : # /sbin/ifup # ip addr show DRACUT (DEBUGGING DRACUT) (Configure a serial console) dracut . . 1. . 2. /boot/grub2/grub.cfg . 'timeout=5' : serial --unit=0 --speed=9600 terminal --timeout=5 serial console 3. /boot/grub2/grub.cfg 'kernel' : console=tty0 console=ttyS0,9600 4. /boot/grub2/grub.cfg . 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. : . 6. /dev/kmsg : # exec >/dev/kmsg 2>&1 dracut (Using the dracut shell) dracut . : 1. 'rd.shell' ( /boot/grub2/grub.cfg) . 2. 'splash' 'quiet' . /boot/grub2/grub.cfg . 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. . No root device found Dropping to debug shell. # 4. ( All bug reports ). dracut (Accessing the root volume from the dracut shell) dracut . . : o ( /dev/sda7) o LVM ( /dev/VolGroup00/LogVol00) o ( /dev/mapper/luks-4d5972ea-901c-4584-bd75-1da802417d83) o ( netroot=iscsi:@192.168.0.4::3260::iqn.2009-02.org.example:for.all) . /dev/root . LVM . 1. 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. LVM . . # lvm vgscan # lvm vgchange -ay 3. 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="ext4" /dev/mapper/linux-swap: UUID="47b4d329-975c-4c08-b218-f9c9bf3635f1" TYPE="swap" 4. . Installation Guide . # 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. # ln -s /dev/mapper/luks-$UUID /dev/root 6. dracut # exit dracut (Additional dracut boot parameters) man:dracut.cmdline[7] . dracut (Debugging dracut on shutdown) systemd rd.break pre-shutdown shutdown . : # 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 (pivot) initramfs dracut . (OPTIONS) --kver . initramfs . : # dracut --kver 3.5.0-0.rc7.git1.2.fc18.x86_64 -f, --force initramfs . --rebuild initramfs . initramfs . initramfs . -a, --add dracut . add omit . . . : # dracut --add "module1 module2" ... --force-add dracut host-only (-H) . --add --force-add (-o) override ( ) . . . : # dracut --force-add "module1 module2" ... -o, --omit dracut . . : dracut dracut . . . : # dracut --omit "module1 module2" ... -m, --modules dracut initramfs. /usr/lib/dracut/modules.d . . dracut dracut . "--add" . ( ). . : # dracut --modules "module1 module2" ... -d, --drivers initramfs. ".ko" . . dracut . "--add-drivers" . ( ). . : # dracut --drivers "kmodule1 kmodule2" ... --add-drivers initramfs. ".ko" . . . : # dracut --add-drivers "kmodule1 kmodule2" ... --force-drivers add-drivers modprobe . . : # dracut --force-drivers "kmodule1 kmodule2" ... --omit-drivers initramfs. ".ko" . . . : # dracut --omit-drivers "kmodule1 kmodule2" ... --filesystems initramfs . . . : # dracut --filesystems "filesystem1 filesystem2" ... -k, --kmoddir . --fwdir [:...]++ (firmware). . --libdirs initramfs . . . : # dracut --libdirs "dir1 dir2" ... --kernel-cmdline . initrd . --kernel-only . --no-kernel . --early-microcode ramdisk. --no-early-microcode ramdisk . --print-cmdline . dracut initrd . --mdadmconf /etc/mdadm.conf. --nomdadmconf /etc/mdadm.conf. --lvmconf /etc/lvm/lvm.conf. --nolvmconf /etc/lvm/lvm.conf. --fscks fsck dracut.conf ( ). . : # dracut --fscks "fsck.foo barfsck" ... --nofscks fsck. --strip (strip) initramfs (). --aggressive-strip initramfs. --strip . --nostrip initramfs. --hardlink (hardlink) initramfs (). --nohardlink initramfs. --prefix initramfs. --noprefix initramfs (). -h, --help . --debug . -v, --verbose ( (3)warnings). . --version . -q, --quiet ( (3)warnings). . -c, --conf . : /etc/dracut.conf --confdir . : /etc/dracut.conf.d --add-confdir *.conf. confdir . : --tmpdir . : /var/tmp -r, --sysroot sysroot . initramfs sysroot (cross-compiled) . (ENVIRONMENT) . : --sshkey SSH ssh-client. --logfile . : /var/log/dracut.log -l, --local . dracut /usr/lib/dracut/modules.d . dracut . -H, --hostonly (host-only): /etc (). initramfs hostonly-mode . chroot "--fstab" /etc/fstab . -N, --no-hostonly host-only. --hostonly-mode host-only . "sloppy" "strict" . "sloppy" ( ) . "strict" . . : sloppy --hostonly-cmdline dracut initrd . etc/cmdline.d initrd . ( UKI) initrd dracut . dracut rootfs-block initrd root= etc/cmdline.d /proc/cmdline . --no-hostonly-cmdline initramfs. dracut initrd etc/cmdline.d initrd . --no-hostonly-default-device swap root fstab . "--mount" "--add-device" . --hostonly-i18n (). --no-hostonly-i18n . --hostonly-nics (NIC) initramfs. . --persistent-policy . /dev/disk ( "by-uuid" "by-label") "mapper" /dev/mapper (). --fstab /etc/fstab /proc/self/mountinfo. --add-fstab /etc/fstab initramfs. --mount " [ [ []]]" initramfs. fstab . "defaults" . "0" . "2" . --mount "" . --add-device initramfs . host-only resume swap LVM . [: --device ] -i, --include SOURCE TARGET initramfs . SOURCE TARGET initramfs . . -I, --install initramfs. . : # dracut --install "/bin/foo /sbin/bar" ... --remove initramfs. file/dir ( glob(7) ). --install-optional initramfs . --gzip initramfs gzip. gzip . "--compress=gzip -9". --bzip2 initramfs bzip2. bzip2 . "--compress=bzip2 -9". --lzma initramfs lzma. lzma . "--compress=lzma -9 -T0". --xz initramfs xz. xz . "--compress=xz --check=crc32 --lzma2=dict=1MiB -T0". --lzo initramfs lzop. lzo . "--compress=lzop -9". --lz4 initramfs lz4. lz4 . "--compress=lz4 -l -9". --zstd initramfs Zstandard. zstd . "--compress=zstd -15 -q -T0". --compress initramfs . . . initramfs . INITRD_COMPRESS . --squash-compressor squashfs mksquashfs. mksquashfs . squash initramfs . --no-compress initramfs . . --reproducible (). --no-reproducible . --list-modules dracut. -M, --show-modules . --keep initramfs . --printconfig . --printsize . --profile . --ro-mnt / /usr . -L, --stdlog [0-6] ( ). 0 - 1 - 2 - 3 - 4 - (info) 5 - ( ) 6 - ( ) --regenerate-all initramfs . . -p, --parallel . --regenerate-all ( initramfs ). --noimageifnotneeded host-only /etc/cmdline/*.conf initramfs . --loginstall . --uefi initramfs dracut UEFI UEFI BIOS . /EFI/Linux/linux-$kernel$--.efi . ESP /efi /boot /boot/efi . BUILD_ID /usr/lib/os-release /etc/os-release BUILD_ID . --ukify ukify UKI (). --no-uefi UEFI. --no-ukify ukify UKI ukify . --no-machineid --uefi . --uefi-stub UEFI stub initramfs . $prefix/lib/systemd/boot/efi/linux.efi.stub . --uefi-splash-image (splash image) UEFI stub . (.bmp) . --kernel-image UEFI . /lib/modules//vmlinuz /boot/vmlinuz- . --sbat SBAT UEFI . SBAT "sbat,1,SBAT Version,sbat,1, : . --enhanced-cpio dracut-cpio man:copy_file_range[2] io::copy() Rust (copy-on-write) . initramfs extent . reflink --no-compress --nostrip initramfs --tmpdir . (ENVIRONMENT) . INITRD_COMPRESS . --compress . DRACUT_LDCONFIG ldconfig . . --sysroot . : ldconfig PKG_CONFIG pkg-config . . --sysroot . : pkg-config DRACUT_TESTBIN . . --sysroot . sysroot (cross-compiled) (/bin/sh) sysroot . : /bin/sh DRACUT_INSTALL dracut-install . . dracut-install dracut . : dracut-install : DRACUT_INSTALL="valgrind dracut-install" 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 . PATH . DRACUT_ARCH uname -m . --sysroot . : empty ( uname -m ) DRACUT_EXTRA_ARGS dracut. (word-split) . (shell-quoted) : DRACUT_EXTRA_ARGS='--add "module1 module2"' dracut SYSTEMD_VERSION systemd . --sysroot . SYSTEMCTL systemctl . --sysroot . NM_VERSION NetworkManager . --sysroot . DRACUT_INSTALL_PATH PATH dracut-install --sysroot . ( Yocto) PATH /bin /usr/bin . dracut-install /bin /usr/bin sysroot . : PATH DRACUT_INSTALL_LOG_TARGET DRACUT_LOG_TARGET dracut-install . dracut-install dracut . : DRACUT_LOG_TARGET DRACUT_INSTALL_LOG_LEVEL DRACUT_LOG_LEVEL dracut-install . dracut-install dracut . : DRACUT_LOG_LEVEL (FILES) /var/log/dracut.log () initramfs /tmp/dracut.log initramfs /var/log/dracut.log /etc/dracut.conf dracut.conf5 /etc/dracut.conf.d/*.conf dracut.conf5 /usr/lib/dracut/dracut.conf.d/*.conf dracut.conf5 initramfs (Configuration in the initramfs) /etc/conf.d/ /etc/conf.d/ initramfs (source) . . /etc/cmdline . /etc/cmdline.d/*.conf . /etc/cmdline.d/*.conf . conf 50-59 . conf dracut 10-49 60-99 . (AVAILABILITY) dracut dracut : "" <"https://github.com/dracut-ng/dracut-ng"> (AUTHORS) Harald Hoyer Victor Lowther Amadeusz Zolnowski Hannes Reinecke Daniel Molkentin Will Woods Philippe Seewer Warren Togami (SEE ALSO) man:dracut.cmdline[7] man:dracut.conf[5] man:lsinitrd[1] dracut 2026-05-13 DRACUT(8)