NAME<\/a> dracut.cmdline \u2212 dracut kernel command line options<\/p>\n The root device used by the kernel is specified in the boot configuration file on the kernel command line, as always.<\/p>\n The traditional root=\/dev\/sda1<\/i> style device specification is allowed, but not encouraged. The root device should better be identified by LABEL or UUID. If a label is used, as in root=LABEL= In the following all kernel command line parameters, which are processed by dracut, are described.<\/p>\n “rd.*” parameters mentioned without “=” are boolean parameters. They can be turned on\/off by setting them to {0|1}. If the assignment with “=” is missing “=1” is implied. For example rd.info<\/i> can be turned off with rd.info=0<\/i> or turned on with rd.info=1<\/i> or rd.info<\/i>. The last value in the kernel command line is the value, which is honored.<\/p>\n Standard specify the path to the init program to be started after the initramfs has finished<\/p>\n root=<\/b> specify the block device to use as the root filesystem.<\/p>\n Example<\/b>.<\/p>\n root=\/dev\/sda1 rootfstype=<\/b> “auto” if not specified.<\/p>\n Example<\/b>.<\/p>\n rootfstype=ext3<\/p>\n rootflags=<\/b> specify additional mount options for the root filesystem. If not set, \/etc\/fstab<\/i> of the real root will be parsed for special mount options and mounted accordingly.<\/p>\n ro<\/b><\/p>\n force mounting \/<\/i> and \/usr<\/i> (if it is a separate device) read\u2212only. If none of ro and rw is present, both are mounted according to \/etc\/fstab<\/i>.<\/p>\n rw<\/b><\/p>\n force mounting \/<\/i> and \/usr<\/i> (if it is a separate device) read\u2212write. See also ro option.<\/p>\n rootfallback=<\/b> specify the block device to use as the root filesystem, if the normal root cannot be found. This can only be a simple block device with a simple file system, for which the filesystem driver is either compiled in, or added manually to the initramfs. This parameter can be specified multiple times.<\/p>\n rd.auto rd.auto=1<\/b><\/p>\n enable autoassembly of special devices like cryptoLUKS, dmraid, mdraid or lvm. Default is off as of dracut version >= 024.<\/p>\n rd.hostonly=0<\/b><\/p>\n removes all compiled in configuration of the host system the initramfs image was built on. This helps booting, if any disk layout changed, especially in combination with rd.auto or other parameters specifying the layout.<\/p>\n rd.cmdline=ask<\/b><\/p>\n prompts the user for additional kernel command line parameters<\/p>\n rd.fstab=0<\/b><\/p>\n do not honor special mount options for the root filesystem found in \/etc\/fstab<\/i> of the real root.<\/p>\n resume=<\/b> resume from a swap partition<\/p>\n Example<\/b>.<\/p>\n resume=\/dev\/disk\/by\u2212path\/pci\u22120000:00:1f.1\u2212scsi\u22120:0:1:0\u2212part1 rd.skipfsck<\/b><\/p>\n skip fsck for rootfs and \/usr<\/i>. If you\u2019re mounting \/usr<\/i> read\u2212only and the init system performs fsck before remount, you might want to use this option to avoid duplication.<\/p>\n iso\u2212scan\/filename<\/b> Example<\/b>.<\/p>\n menuentry ‘Live Fedora 20’ \u2212\u2212class fedora \u2212\u2212class gnu\u2212linux \u2212\u2212class gnu \u2212\u2212class os { Misc specify, what action to execute in case of a critical failure. rd.shell=0 also be specified.<\/p>\n rd.driver.blacklist=<\/b> do not load kernel module rd.driver.pre=<\/b> force loading kernel module rd.driver.post=<\/b> force loading kernel module rd.retry=<\/b> specify how long dracut should retry the initqueue to configure devices. The default is 30 seconds. After 2\/3 of the time, degraded raids are force started. If you have hardware, which takes a very long time to announce its drives, you might want to extend this value.<\/p>\n rd.timeout=<\/b> specify how long dracut should wait for devices to appear. The default is 0<\/i>, which means forever<\/i>. Note that this timeout should be longer than rd.retry to allow for proper configuration.<\/p>\n rd.noverifyssl<\/b><\/p>\n accept self\u2212signed certificates for ssl downloads.<\/p>\n rd.ctty=<\/b> specify the controlling terminal for the console. This is useful, if you have multiple “console=” arguments.<\/p>\n Debug<\/b> rd.info<\/b><\/p>\n print informational output though “quiet” is set<\/p>\n rd.shell<\/b><\/p>\n allow dropping to a shell, if root mounting fails<\/p>\n rd.debug<\/b><\/p>\n set \u2212x for the dracut shell. If systemd is active in the initramfs, all output is logged to the systemd journal, which you can inspect with “journalctl \u2212ab”. If systemd is not active, the logs are written to dmesg and \/run\/initramfs\/init.log<\/i>. If “quiet” is set, it also logs to the console.<\/p>\n rd.memdebug=[0\u22125]<\/b><\/p>\n Print memory usage info at various points, set the verbose level from 0 to 5.<\/p>\n Higher level means more debugging output:<\/p>\n 0 \u2212 no output rd.break<\/b><\/p>\n drop to a shell at the end<\/p>\n rd.break=<\/b>{cmdline|pre\u2212udev|pre\u2212trigger|initqueue|pre\u2212mount|mount|pre\u2212pivot|cleanup}<\/i><\/p>\n drop to a shell on defined breakpoint<\/p>\n rd.udev.info<\/b><\/p>\n set udev to loglevel info<\/p>\n rd.udev.debug<\/b><\/p>\n set udev to loglevel debug<\/p>\n I18N keyboard translation table loaded by loadkeys; taken from keymaps directory; will be written as KEYMAP to \/etc\/vconsole.conf<\/i> in the initramfs.<\/p>\n Example<\/b>.<\/p>\n rd.vconsole.keymap=de\u2212latin1\u2212nodeadkeys<\/p>\n rd.vconsole.keymap.ext=<\/b> list of extra keymaps to bo loaded (sep. by space); will be written as EXT_KEYMAP to \/etc\/vconsole.conf<\/i> in the initramfs<\/p>\n rd.vconsole.unicode<\/b><\/p>\n boolean, indicating UTF\u22128 mode; will be written as UNICODE to \/etc\/vconsole.conf<\/i> in the initramfs<\/p>\n rd.vconsole.font=<\/b><\/i><\/p>\n console font; taken from consolefonts directory; will be written as FONT to \/etc\/vconsole.conf<\/i> in the initramfs.<\/p>\n Example<\/b>.<\/p>\n rd.vconsole.font=eurlatgr<\/p>\n rd.vconsole.font.map=<\/b> see description of \u2212m<\/i> parameter in setfont manual; taken from consoletrans directory; will be written as FONT_MAP to \/etc\/vconsole.conf<\/i> in the initramfs<\/p>\n rd.vconsole.font.unimap=<\/b> see description of \u2212u<\/i> parameter in setfont manual; taken from unimaps directory; will be written as FONT_UNIMAP to \/etc\/vconsole.conf<\/i> in the initramfs<\/p>\n rd.locale.LANG=<\/b> taken from the environment; if no UNICODE is defined we set its value in basis of LANG value (whether it ends with “.utf8” (or similar) or not); will be written as LANG to \/etc\/locale.conf<\/i> in the initramfs.<\/p>\n Example<\/b>.<\/p>\n rd.locale.LANG=pl_PL.utf8<\/p>\n rd.locale.LC_ALL=<\/b> taken from the environment; will be written as LC_ALL to \/etc\/locale.conf<\/i> in the initramfs<\/p>\n LVM disable LVM detection<\/p>\n rd.lvm.vg=<\/b> only activate all logical volumes in the the volume groups with the given name. rd.lvm.vg can be specified multiple times on the kernel command line.<\/p>\n rd.lvm.lv=<\/b> only activate the logical volumes with the given name. rd.lvm.lv can be specified multiple times on the kernel command line.<\/p>\n rd.lvm.conf=0<\/b><\/p>\n remove any \/etc\/lvm\/lvm.conf<\/i>, which may exist in the initramfs<\/p>\n crypto LUKS disable crypto LUKS detection<\/p>\n rd.luks.uuid=<\/b> only activate the LUKS partitions with the given UUID. Any “luks\u2212” of the LUKS UUID is removed before comparing to rd.luks.allow\u2212discards=<\/b> Allow using of discards (TRIM) requests for LUKS partitions with the given UUID. Any “luks\u2212” of the LUKS UUID is removed before comparing to rd.luks.allow\u2212discards<\/b><\/p>\n Allow using of discards (TRIM) requests on all LUKS partitions.<\/p>\n rd.luks.crypttab=0<\/b><\/p>\n do not check, if LUKS partition is in \/etc\/crypttab<\/i><\/p>\n rd.luks.timeout=<\/b> specify how long dracut should wait when waiting for the user to enter the password. This avoid blocking the boot if no password is entered. It does not apply to luks key. The default is 0<\/i>, which means forever<\/i>.<\/p>\n crypto LUKS \u2212 key on removable device support<\/b> rd.luks.key=<\/b> If Example<\/b>.<\/font><\/p>\n rd.luks.key=\/foo\/bar.key<\/font><\/p>\n As you see, you can skip colons in such a case.<\/font><\/p>\n Note<\/big><\/b> dracut provides keys to cryptsetup with \u2212d<\/i> (an older alias for \u2212\u2212key\u2212file<\/i>). This uses the entire binary content of the key file as part of the secret. If you pipe a password into cryptsetup without<\/b> \u2212d<\/i> or \u2212\u2212key\u2212file<\/i>, it will be treated as text user input, and only characters before the first newline will be used. Therefore, when you\u2019re creating an encrypted partition for dracut to mount, and you pipe a key into cryptsetup luksFormat<\/i>,you must use \u2212d \u2212<\/i>.<\/font><\/p>\n Here is an example for a key encrypted with GPG (warning: \u2212\u2212batch\u2212mode<\/i> will overwrite the device without asking for confirmation):<\/font><\/p>\n gpg \u2212\u2212quiet \u2212\u2212decrypt rootkey.gpg | If you use unencrypted key files, just use the key file pathname instead of the standard input. For a random key with 256 bits of entropy, you might use:<\/font><\/p>\n head \u221232c \/dev\/urandom > rootkey.key You can also use regular key files on an encrypted keydev<\/i>.<\/font><\/p>\n Compared to using GPG encrypted keyfiles on an unencrypted device this provides the following advantages:<\/font><\/p>\n \u2022 you can unlock your disk(s) using multiple passphrases<\/font><\/p>\n \u2022 better security by not loosing the key stretching mechanism<\/font><\/p>\n To use an encrypted keydev<\/i> you must<\/b> ensure that it becomes available by using the keyword keysource, e.g. rd.luks.uuid=keysource:aaaa aaaa<\/i> being the uuid of the encrypted keydev<\/i>.<\/font><\/p>\n Example:<\/font><\/p>\n Lets assume you have three disks A<\/i>, B<\/i> and C<\/i> with the uuids aaaa<\/i>, bbbb<\/i> and cccc<\/i>. You want to unlock A<\/i> and B<\/i> using keyfile keyfile<\/i>. The unlocked volumes be A’<\/i>, B’<\/i> and C’<\/i> with the uuids AAAA<\/i>, BBBB<\/i> and CCCC<\/i>. keyfile<\/i> is saved on C’<\/i> as \/keyfile<\/i>.<\/font><\/p>\n One luks keyslot of each A<\/i>, B<\/i> and C<\/i> is setup with a passphrase. Another luks keyslot of each A<\/i> and B<\/i> is setup with keyfile<\/i>.<\/font><\/p>\n To boot this configuration you could use:<\/font><\/p>\n rd.luks.uuid=aaaa Dracut asks for the passphrase for C<\/i> and uses the keyfile to unlock A<\/i> and B<\/i>. If getting the passphrase for C<\/i> fails it falls back to asking for the passphrases for A<\/i> and B<\/i>.<\/font><\/p>\n If you want C’<\/i> to stay unlocked, specify a luks name for it, e.g. rd.luks.name=cccc=mykeys, otherwise it gets closed when not needed anymore.<\/font><\/p>\n MD RAID disable MD RAID detection<\/big><\/font><\/p>\n rd.md.imsm=0<\/b><\/big><\/font><\/p>\n disable MD RAID for imsm\/isw raids, use DM RAID instead<\/big><\/font><\/p>\n rd.md.ddf=0<\/b><\/big><\/font><\/p>\n disable MD RAID for SNIA ddf raids, use DM RAID instead<\/big><\/font><\/p>\n rd.md.conf=0<\/b><\/big><\/font><\/p>\n ignore mdadm.conf included in initramfs<\/big><\/font><\/p>\n rd.md.waitclean=1<\/b><\/big><\/font><\/p>\n wait for any resync, recovery, or reshape activity to finish before continuing<\/big><\/font><\/p>\n rd.md.uuid=<\/b> only activate the raid sets with the given UUID. This parameter can be specified multiple times.<\/big><\/font><\/p>\n DM RAID disable DM RAID detection<\/big><\/font><\/p>\n rd.dm.uuid=<\/b> only activate the raid sets with the given UUID. This parameter can be specified multiple times.<\/big><\/font><\/p>\n MULTIPATH disable multipath detection<\/big><\/font><\/p>\n
DESCRIPTION<\/a>
AUTHOR<\/a>
SEE ALSO<\/a>
NOTES<\/a> <\/p>\n
\nNAME <\/a> <\/h2>\n
DESCRIPTION <\/a> <\/h2>\n
init=<\/b>
root=\/dev\/disk\/by\u2212path\/pci\u22120000:00:1f.1\u2212scsi\u22120:0:1:0\u2212part1
root=\/dev\/disk\/by\u2212label\/Root
root=LABEL=Root
root=\/dev\/disk\/by\u2212uuid\/3f5ad593\u22124546\u22124a94\u2212a374\u2212bcfb68aa11f7
root=UUID=3f5ad593\u22124546\u22124a94\u2212a374\u2212bcfb68aa11f7
root=PARTUUID=3f5ad593\u22124546\u22124a94\u2212a374\u2212bcfb68aa11f7<\/p>\n
resume=\/dev\/disk\/by\u2212uuid\/3f5ad593\u22124546\u22124a94\u2212a374\u2212bcfb68aa11f7
resume=UUID=3f5ad593\u22124546\u22124a94\u2212a374\u2212bcfb68aa11f7<\/p>\n
Mount all mountable devices and search for ISO pointed by the argument. When the ISO is found set it up as a loop device. Device containing this ISO image will stay mounted at \/run\/initramfs\/isoscandev. Using iso\u2212scan\/filename with a Fedora\/Red Hat\/CentOS Live iso should just work by copying the original kernel cmdline parameters.<\/p>\n
set isolabel=Fedora\u2212Live\u2212LXDE\u2212x86_64\u221220\u22121
set isofile=”\/boot\/iso\/Fedora\u2212Live\u2212LXDE\u2212x86_64\u221220\u22121.iso”
loopback loop $isofile
linux (loop)\/isolinux\/vmlinuz0 boot=isolinux iso\u2212scan\/filename=$isofile root=live:LABEL=$isolabel ro rd.live.image quiet rhgb
initrd (loop)\/isolinux\/initrd0.img
}<\/p>\n
rd.emergency=<\/b>[reboot|poweroff|halt]<\/i><\/p>\n
If you are dropped to an emergency shell, the file \/run\/initramfs\/rdsosreport.txt<\/i> 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<\/b> to the kernel command line. \/run\/initramfs\/rdsosreport.txt<\/i> contains all logs and the output of some tools. It should be attached to any report about dracut problems.<\/p>\n
1 \u2212 partial \/proc\/meminfo
2 \u2212 \/proc\/meminfo
3 \u2212 \/proc\/meminfo + \/proc\/slabinfo
4 \u2212 \/proc\/meminfo + \/proc\/slabinfo + memstrack summary
NOTE: memstrack is a memory tracing tool that tracks the total memory
consumption, and peak memory consumption of each kernel modules
and userspace progress during the whole initramfs runtime, report
is genereted and the end of initramsfs run.
5 \u2212 \/proc\/meminfo + \/proc\/slabinfo + memstrack (with top memory stacktrace)
NOTE: memstrack (with top memory stacktrace) will print top memory
allocation stack traces during the whole initramfs runtime.<\/p>\n
rd.vconsole.keymap=<\/b><\/i><\/p>\n
rd.lvm=0<\/b><\/p>\n
rd.luks=0<\/b><\/p>\n
NB: If systemd is included in the dracut initrd, dracut\u2019s built in removable device keying support won\u2019t work. systemd will prompt for a password from the console even if you\u2019ve supplied rd.luks.key<\/b>. You may be able to use standard systemd fstab<\/b>(5) syntax to get the same effect. If you do need rd.luks.key<\/b> to work, you will have to exclude the “systemd” dracut module and any modules that depend on it. See dracut.conf<\/b>(5) and https:\/\/bugzilla.redhat.com\/show_bug.cgi?id=905683<\/font><\/b> for more information.<\/font><\/p>\n
Your LUKS partition must match your key file.<\/font><\/p>\n
cryptsetup \u2212\u2212batch\u2212mode \u2212\u2212key\u2212file \u2212
luksFormat \/dev\/sda47<\/font><\/p>\n
cryptsetup \u2212\u2212batch\u2212mode \u2212\u2212key\u2212file rootkey.key
luksFormat \/dev\/sda47<\/font><\/p>\n
rd.luks.uuid=bbbb
rd.luks.uuid=keysource:cccc
rd.luks.key=\/keyfile:UUID=CCCC<\/font><\/p>\n
rd.md=0<\/big><\/b><\/font><\/p>\n
rd.dm=0<\/b><\/big><\/font><\/p>\n
rd.multipath=0<\/b><\/big><\/font><\/p>\n