# dracut.cmdline

## NAME



           dracut.cmdline - dracut kernel command line options
    


## DESCRIPTION



           The root device used by the kernel is specified in the boot
           configuration file on the kernel command line, as always.
    
           The traditional _root=/dev/sda1_ 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= <label_of_root>_ the initramfs will search all available
           devices for a filesystem with the appropriate label, and mount
           that device as the root filesystem. _root=UUID= <uuidnumber>_ will
           mount the partition with that UUID as the root filesystem.
    
           In the following all kernel command line parameters, which are
           processed by dracut, are described.
    
           "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_ can be turned off with _rd.info=0_ or turned on with
           _rd.info=1_ or _rd.info_. The last value in the kernel command line is
           the value, which is honored.
    
       **Standard**
           **init=**_< path to real init>_
               specify the path to the init program to be started after the
               initramfs has finished
    
           **root=**_< path to blockdevice>_
               specify the block device to use as the root filesystem.
    
               **Example**
    
                   root=/dev/sda1
                   root=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
                   root=/dev/disk/by-label/Root
                   root=LABEL=Root
                   root=/dev/disk/by-uuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
                   root=UUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
                   root=PARTUUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
    
           **rootfstype=**_< filesystem type>_
               "auto" if not specified.
    
               **Example**
    
                   rootfstype=ext4
    
           **rootflags=**_< mount options>_
               specify additional mount options for the root filesystem. If
               not set, _/etc/fstab_ of the real root will be parsed for
               special mount options and mounted accordingly.
    
           **ro**
               force mounting _/_ and _/usr_ (if it is a separate device)
               read-only. If none of ro and rw is present, both are mounted
               according to _/etc/fstab_.
    
           **rw**
               force mounting _/_ and _/usr_ (if it is a separate device)
               read-write. See also ro option.
    
           **rootfallback=**_< path to blockdevice>_
               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.
    
           **rd.auto rd.auto=1**
               enable autoassembly of special devices like cryptoLUKS,
               dmraid, mdraid or lvm. Default is off as of dracut version >=
               024.
    
           **rd.hostonly=0**
               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.
    
           **rd.cmdline=ask**
               prompts the user for additional kernel command line parameters
    
           **rd.fstab=0**
               do not honor special mount options for the root filesystem
               found in _/etc/fstab_ of the real root.
    
           **resume=**_< path to resume partition>_
               resume from a swap partition
    
               **Example**
    
                   resume=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
                   resume=/dev/disk/by-uuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
                   resume=UUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
    
           **rd.skipfsck**
               skip fsck for rootfs and _/usr_. If you’re mounting _/usr_
               read-only and the init system performs fsck before remount,
               you might want to use this option to avoid duplication.
    
       **iso-scan/filename**
           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-scan/filename with a
           Fedora/Red Hat/CentOS Live iso should just work by copying the
           original kernel cmdline parameters.
    
           **Example**
    
               menuentry 'Live' --class gnu-linux --class gnu --class os {
                   set isolabel=Live-x86_64
                   set isofile="/boot/iso/Live-x86_64.iso"
                   loopback loop $isofile
                   linux (loop)/isolinux/vmlinuz0 boot=isolinux iso-scan/filename=$isofile root=live:LABEL=$isolabel ro rd.live.image quiet
                   initrd (loop)/isolinux/initrd0.img
               }
    
       **Misc**
           **rd.emergency=**_[reboot|poweroff|halt]_
               specify, what action to execute in case of a critical failure.
               rd.shell=0 must also be specified.
    
           **rd.driver.blacklist=**_< drivername>_[,_< drivername>_,...]
               do not load kernel module <drivername>. This parameter can be
               specified multiple times.
    
           **rd.driver.pre=**_< drivername>_[,_< drivername>_,...]
               force loading kernel module <drivername>. This parameter can
               be specified multiple times.
    
           **rd.driver.post=**_< drivername>_[,_< drivername>_,...]
               force loading kernel module <drivername> after all automatic
               loading modules have been loaded. This parameter can be
               specified multiple times.
    
           **rd.retry=**_< seconds>_
               specify how long dracut should retry the initqueue to
               configure devices. The default is 180 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.
    
           **rd.timeout=**_< seconds>_
               specify how long dracut should wait for devices to appear. The
               default is _0_ , which means _forever_. Note that this timeout
               should be longer than rd.retry to allow for proper
               configuration.
    
           **rd.noverifyssl**
               accept self-signed certificates for ssl downloads.
    
           **rd.ctty=**_< terminal device>_
               specify the controlling terminal for the console. This is
               useful, if you have multiple "console=" arguments.
    
           **rd.shutdown.timeout.umount=**_< seconds>_
               specify how long dracut should wait for an individual umount
               to finish during shutdown. This avoids the system from
               blocking when unmounting a file system cannot complete and
               waits indefinitely. Value _0_ means to wait _forever_. The default
               is 90 seconds.
    
       **Debug**
           If you are dropped to an emergency shell, 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.
    
           **rd.info**
               print informational output though "quiet" is set
    
           **rd.shell**
               allow dropping to a shell, if root mounting fails
    
           **rd.debug**
               set -x 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 -ab". If systemd is not
               active, the logs are written to dmesg and
               _/run/initramfs/init.log_. If "quiet" is set, it also logs to
               the console.
    
           **rd.memdebug=[0-5]**
               Print memory usage info at various points, set the verbose
               level from 0 to 5.
    
                   Higher level means more debugging output:
    
                       0 - no output
                       1 - partial /proc/meminfo
                       2 - /proc/meminfo
                       3 - /proc/meminfo + /proc/slabinfo
                       4 - /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 generated and the end of initramfs run.
                       5 - /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.
    
           **rd.break**
               drop to a shell at the end
    
           **rd.break=**_{cmdline|pre-udev|pre-trigger|initqueue|pre-mount|mount|pre-pivot|cleanup}_
               drop to a shell before the defined breakpoint starts. This
               parameter can be specified multiple times.
    
           **rd.udev.log_level=**_{err|info|debug}_
               set udev log level. The default is _err_.
    
       **I18N**
           **rd.vconsole.keymap=**_< keymap base file name>_
               keyboard translation table loaded by loadkeys; taken from
               keymaps directory; will be written as KEYMAP to
               _/etc/vconsole.conf_ in the initramfs.
    
               **Example**
    
                   rd.vconsole.keymap=de-latin1-nodeadkeys
    
           **rd.vconsole.keymap.ext=**_< list of keymap base file names>_
               list of extra keymaps to bo loaded (sep. by space); will be
               written as EXT_KEYMAP to _/etc/vconsole.conf_ in the initramfs
    
           **rd.vconsole.unicode**
               boolean, indicating UTF-8 mode; will be written as UNICODE to
               _/etc/vconsole.conf_ in the initramfs
    
           **rd.vconsole.font=**_< font base file name>_
               console font; taken from consolefonts directory; will be
               written as FONT to _/etc/vconsole.conf_ in the initramfs.
    
               **Example**
    
                   rd.vconsole.font=eurlatgr
    
           **rd.vconsole.font.map=**_< console map base file name>_
               see description of _-m_ parameter in setfont manual; taken from
               consoletrans directory; will be written as FONT_MAP to
               _/etc/vconsole.conf_ in the initramfs
    
           **rd.vconsole.font.unimap=**_< unicode table base file name>_
               see description of _-u_ parameter in setfont manual; taken from
               unimaps directory; will be written as FONT_UNIMAP to
               _/etc/vconsole.conf_ in the initramfs
    
           **rd.locale.LANG=**_< locale>_
               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_ in the initramfs.
    
               **Example**
    
                   rd.locale.LANG=pl_PL.utf8
    
           **rd.locale.LC_ALL=**_< locale>_
               taken from the environment; will be written as LC_ALL to
               _/etc/locale.conf_ in the initramfs
    
       **LVM**
           **rd.lvm=0**
               disable LVM detection
    
           **rd.lvm.vg=**_< volume group name>_
               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.
    
           **rd.lvm.lv=**_< volume group name>/<logical volume name>_
               only activate the logical volumes with the given name.
               rd.lvm.lv can be specified multiple times on the kernel
               command line.
    
           **rd.lvm.conf=0**
               remove any _/etc/lvm/lvm.conf_ , which may exist in the initramfs
    
       **crypto LUKS**
           **rd.luks=0**
               disable crypto LUKS detection
    
           **rd.luks.uuid=**_< luks uuid>_
               only activate the LUKS partitions with the given UUID. Any
               "luks-" of the LUKS UUID is removed before comparing to _< luks_
               _uuid >_. The comparisons also matches, if _< luks uuid>_ is only
               the beginning of the LUKS UUID, so you don’t have to specify
               the full UUID. This parameter can be specified multiple times.
               _< luks uuid>_ may be prefixed by the keyword keysource:, see
               _rd.luks.key_ below.
    
           **rd.luks.allow-discards=**_< luks uuid>_
               Allow  using  of discards (TRIM) requests for LUKS partitions
               with the given UUID. Any "luks-" of the LUKS UUID is removed
               before comparing to _< luks uuid>_. The comparisons also matches,
               if _< luks uuid>_ is only the beginning of the LUKS UUID, so you
               don’t have to specify the full UUID. This parameter can be
               specified multiple times.
    
           **rd.luks.allow-discards**
               Allow  using  of discards (TRIM) requests on all LUKS
               partitions.
    
           **rd.luks.crypttab=0**
               do not check, if LUKS partition is in _/etc/crypttab_
    
           **rd.luks.timeout=**_< seconds>_
               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_ , which means _forever_.
    
       **crypto LUKS - key on removable device support**
           NB: If systemd is included in the dracut initrd, dracut’s built in
           removable device keying support won’t work. systemd will prompt
           for a password from the console even if you’ve supplied
           **rd.luks.key**. You may be able to use standard systemd
           man:fstab[5,external] syntax to get the same effect. If you do
           need **rd.luks.key** to work, you will have to exclude the "systemd"
           dracut module and any modules that depend on it. See
           man:dracut.conf[5] and
           https://bugzilla.redhat.com/show_bug.cgi?id=905683 for more
           information.
    
           **rd.luks.key=**_< keypath>[:<keydev>[:<luksdev>]]_
               _< keypath>_ is the pathname of a key file, relative to the root
               of the filesystem on some device. It’s REQUIRED. When
               _< keypath>_ ends with _.gpg_ it’s considered to be key encrypted
               symmetrically with GPG. You will be prompted for the GPG
               password on boot. GPG support comes with the _crypt-gpg_ module,
               which needs to be added explicitly.
    
               _< keydev>_ identifies the device on which the key file resides.
               It may be the kernel name of the device (should start with
               "/dev/"), a UUID (prefixed with "UUID=") or a label (prefix
               with "LABEL="). You don’t have to specify a full UUID. Just
               its beginning will suffice, even if its ambiguous. All
               matching devices will be probed. This parameter is
               recommended, but not required. If it’s not present, all block
               devices will be probed, which may significantly increase boot
               time.
    
               If _< luksdev>_ is given, the specified key will only be used for
               the specified LUKS device. Possible values are the same as for
               _< keydev>_. Unless you have several LUKS devices, you don’t have
               to specify this parameter. The simplest usage is:
    
               **Example**
    
                   rd.luks.key=/foo/bar.key
    
               As you see, you can skip colons in such a case.
    
               **Note**
    
               Your LUKS partition must match your key file.
    
               dracut provides keys to cryptsetup with _-d_ (an older alias for
               _--key-file_). This uses the entire binary content of the key
               file as part of the secret. If you pipe a password into
               cryptsetup **without** _-d_ or _--key-file_ , it will be treated as
               text user input, and only characters before the first newline
               will be used. Therefore, when you’re creating an encrypted
               partition for dracut to mount, and you pipe a key into
               _cryptsetup luksFormat_ ,you must use _-d -_.
    
               Here is an example for a key encrypted with GPG (warning:
               _--batch-mode_ will overwrite the device without asking for
               confirmation):
    
                   gpg --quiet --decrypt rootkey.gpg | \
                   cryptsetup --batch-mode --key-file - \
                              luksFormat /dev/sda47
    
               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:
    
                   head -32c /dev/urandom > rootkey.key
                   cryptsetup --batch-mode --key-file rootkey.key \
                              luksFormat /dev/sda47
    
               You can also use regular key files on an encrypted _keydev_.
    
               Compared to using GPG encrypted keyfiles on an unencrypted
               device this provides the following advantages:
    
               •   you can unlock your disk(s) using multiple passphrases
    
               •   better security by not losing the key stretching mechanism
    
               To use an encrypted _keydev_ you **must** ensure that it becomes
               available by using the keyword keysource, e.g.
               rd.luks.uuid=keysource:aaaa _aaaa_ being the uuid of the
               encrypted _keydev_.
    
               Example:
    
               Lets assume you have three disks _A_ , _B_ and _C_ with the uuids
               _aaaa_ , _bbbb_ and _cccc_.
               You want to unlock _A_ and _B_ using keyfile _keyfile_.
               The unlocked volumes be _A'_ , _B'_ and _C'_ with the uuids _AAAA_ ,
               _BBBB_ and _CCCC_.
               _keyfile_ is saved on _C'_ as _/keyfile_.
    
               One luks keyslot of each _A_ , _B_ and _C_ is setup with a
               passphrase.
               Another luks keyslot of each _A_ and _B_ is setup with _keyfile_.
    
               To boot this configuration you could use:
    
                   rd.luks.uuid=aaaa
                   rd.luks.uuid=bbbb
                   rd.luks.uuid=keysource:cccc
                   rd.luks.key=/keyfile:UUID=CCCC
    
               Dracut asks for the passphrase for _C_ and uses the keyfile to
               unlock _A_ and _B_.
               If getting the passphrase for _C_ fails it falls back to asking
               for the passphrases for _A_ and _B_.
    
               If you want _C'_ to stay unlocked, specify a luks name for it,
               e.g. rd.luks.name=cccc=mykeys, otherwise it gets closed when
               not needed anymore.
    
           **rd.luks.key.tout=0**
               specify how many times dracut will try to read the keys
               specified in rd.luks.key. This gives a chance to the removable
               device containing the key to initialize.
    
       **MD RAID**
           **rd.md=0**
               disable MD RAID detection
    
           **rd.md.imsm=0**
               disable MD RAID for imsm/isw raids, use DM RAID instead
    
           **rd.md.ddf=0**
               disable MD RAID for SNIA ddf raids, use DM RAID instead
    
           **rd.md.conf=0**
               ignore mdadm.conf included in initramfs
    
           **rd.md.waitclean=1**
               wait for any resync, recovery, or reshape activity to finish
               before continuing
    
           **rd.md.uuid=**_< md raid uuid>_
               only activate the raid sets with the given UUID. This
               parameter can be specified multiple times.
    
       **DM RAID**
           **rd.dm=0**
               disable DM RAID detection
    
           **rd.dm.uuid=**_< dm raid uuid>_
               only activate the raid sets with the given UUID. This
               parameter can be specified multiple times.
    
       **MULTIPATH**
           **rd.multipath=0**
               disable multipath detection
    
           **rd.multipath=default**
               use default multipath settings
    
       **FIPS**
           **rd.fips**
               enable FIPS
    
           **boot=**_< boot device>_
               specify the device, where /boot is located.
    
               **Example**
    
                   boot=/dev/sda1
                   boot=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
                   boot=UUID=<uuid>
                   boot=LABEL=<label>
    
           **rd.fips.skipkernel**
               skip checksum check of the kernel image. Useful, if the kernel
               image is not in a separate boot partition.
    
       **Network**
               **Important**
    
               It is recommended to either bind an interface to a MAC with
               the **ifname** argument, or to use the systemd-udevd predictable
               network interface names.
    
               Predictable network interface device names based on:
    
               •   firmware/bios-provided index numbers for on-board devices
    
               •   firmware-provided pci-express hotplug slot index number
    
               •   physical/geographical location of the hardware
    
               •   the interface’s MAC address
    
               See:
               http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames
    
               Two character prefixes based on the type of interface:
    
               en
                   ethernet
    
               wl
                   wlan
    
               ww
                   wwan
    
               Type of names:
    
               o<index>
                   on-board device index number
    
               s<slot>[f<function>][d<dev_id>]
                   hotplug slot index number
    
               x<MAC>
                   MAC address
    
               [P<domain>]p<bus>s<slot>[f<function>][d<dev_id>]
                   PCI geographical location
    
               [P<domain>]p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]
                   USB port number chain
    
               All multi-function PCI devices will carry the [f<function>]
               number in the device name, including the function 0 device.
    
               When using PCI geography, The PCI domain is only prepended
               when it is not 0.
    
               For USB devices the full chain of port numbers of hubs is
               composed. If the name gets longer than the maximum number of
               15 characters, the name is not exported. The usual USB
               configuration == 1 and interface == 0 values are suppressed.
    
               PCI ethernet card with firmware index "1"
    
                   •   eno1
    
               PCI ethernet card in hotplug slot with firmware index number
    
                   •   ens1
    
               PCI ethernet multi-function card with 2 ports
    
                   •   enp2s0f0
    
                   •   enp2s0f1
    
               PCI wlan card
    
                   •   wlp3s0
    
               USB built-in 3G modem
    
                   •   wwp0s29u1u4i6
    
               USB Android phone
    
                   •   enp0s29u1u2
    
           The following options are supported by the _network-legacy_ dracut
           module. Other network modules might support a slightly different
           set of options; refer to the documentation of the specific network
           module in use. For NetworkManager, see man:nm-initrd-generator[8].
    
           **ip=**_{dhcp|on|any|dhcp6|auto6|either6|link6|single-dhcp}_
    
               dhcp|on|any
                   get ip from dhcp server from all interfaces. If
                   netroot=dhcp, loop sequentially through all interfaces
                   (eth0, eth1, ...) and use the first with a valid DHCP
                   root-path.
    
               single-dhcp
                   Send DHCP on all available interfaces in parallel, as
                   opposed to one after another. After the first DHCP
                   response is received, stop DHCP on all other interfaces.
                   This gives the fastest boot time by using the IP on
                   interface for which DHCP succeeded first during early
                   boot. Caveat: Does not apply to Network Manager.
    
               auto6
                   IPv6 autoconfiguration
    
               dhcp6
                   IPv6 DHCP
    
               either6
                   if auto6 fails, then dhcp6
    
               link6
                   bring up interface for IPv6 link-local addressing
    
           **ip=**_< interface>_:_{dhcp|on|any|dhcp6|auto6|link6}_[:[_< mtu>_][:_< macaddr>_]]
               This parameter can be specified multiple times.
    
                   dhcp|on|any|dhcp6
                       get ip from dhcp server on a specific interface
    
                   auto6
                       do IPv6 autoconfiguration
    
                   link6
                       bring up interface for IPv6 link local address
    
                   <macaddr>
                       optionally **set** <macaddr> on the <interface>. This
                       cannot be used in conjunction with the **ifname** argument
                       for the same <interface>.
    
           **ip=**_< client-IP>_:[_< peer>_]:_< gateway-IP>_:_< netmask>_:_< client_hostname>_:_< interface>_:_{none|off|dhcp|on|any|dhcp6|auto6|ibft}_[:[_< mtu>_][:_< macaddr>_]]
               explicit network configuration. If you want do define a IPv6
               address, put it in brackets (e.g. [2001:DB8::1]). This
               parameter can be specified multiple times. _< peer>_ is optional
               and is the address of the remote endpoint for pointopoint
               interfaces and it may be followed by a slash and a decimal
               number, encoding the network prefix length.
    
                   <macaddr>
                       optionally **set** <macaddr> on the <interface>. This
                       cannot be used in conjunction with the **ifname** argument
                       for the same <interface>.
    
           **ip=**_< client-IP>_:[_< peer>_]:_< gateway-IP>_:_< netmask>_:_< client_hostname>_:_< interface>_:_{none|off|dhcp|on|any|dhcp6|auto6|ibft}_[:[_< dns1>_][:_< dns2>_]]
               explicit network configuration. If you want do define a IPv6
               address, put it in brackets (e.g. [2001:DB8::1]). This
               parameter can be specified multiple times. _< peer>_ is optional
               and is the address of the remote endpoint for pointopoint
               interfaces and it may be followed by a slash and a decimal
               number, encoding the network prefix length.
    
           **ifname=**_< interface>_:_< MAC>_
               Assign network device name <interface> (i.e. "bootnet") to the
               NIC with MAC <MAC>.
    
                   **Warning**
    
                   Do **not** use the default kernel naming scheme for the
                   interface name, as it can conflict with the kernel names.
                   So, don’t use "eth[0-9]+" for the interface name. Better
                   name it "bootnet" or "bluesocket".
    
           **rd.route=**_< net>_/_< netmask>_:_< gateway>_[:_< interface>_]
               Add a static route with route options, which are separated by
               a colon. IPv6 addresses have to be put in brackets.
    
               **Example**
    
                       rd.route=192.168.200.0/24:192.168.100.222:ens10
                       rd.route=192.168.200.0/24:192.168.100.222
                       rd.route=192.168.200.0/24::ens10
                       rd.route=[2001:DB8:3::/8]:[2001:DB8:2::1]:ens10
    
           **bootdev=**_< interface>_
               specify network interface to use routing and netroot
               information from. Required if multiple ip= lines are used.
    
           **BOOTIF=**_< MAC>_
               specify network interface to use routing and netroot
               information from.
    
           **rd.bootif=0**
               Disable BOOTIF parsing, which is provided by PXE
    
           **nameserver=**_< IP>_ [**nameserver=**_< IP>_ ...]
               specify nameserver(s) to use
    
           **rd.peerdns=0**
               Disable DNS setting of DHCP parameters.
    
           **biosdevname=0**
               boolean, turn off biosdevname network interface renaming
    
           **rd.neednet=1**
               boolean, bring up network even without netroot set
    
           **vlan=**_< vlanname>_:_< phydevice>_
               Setup vlan device named <vlanname> on <phydevice>. We support
               the four styles of vlan names: VLAN_PLUS_VID (vlan0005),
               VLAN_PLUS_VID_NO_PAD (vlan5), DEV_PLUS_VID (eth0.0005),
               DEV_PLUS_VID_NO_PAD (eth0.5)
    
           **bond=**_< bondname>_[:_< bondslaves>_:[:_< options>_[:<mtu>]]]
               Setup bonding device <bondname> on top of <bondslaves>.
               <bondslaves> is a comma-separated list of physical (ethernet)
               interfaces. <options> is a comma-separated list on bonding
               options (modinfo bonding for details) in format compatible
               with initscripts. If <options> includes multi-valued
               arp_ip_target option, then its values should be separated by
               semicolon. if the mtu is specified, it will be set on the bond
               master. Bond without parameters assumes
               bond=bond0:eth0,eth1:mode=balance-rr
    
           **team=**_< teammaster>_:_< teamslaves>_[:_< teamrunner>_]
               Setup team device <teammaster> on top of <teamslaves>.
               <teamslaves> is a comma-separated list of physical (ethernet)
               interfaces. <teamrunner> is the runner type to be used (see
               man:teamd.conf[5,external]); defaults to activebackup. Team
               without parameters assumes team=team0:eth0,eth1:activebackup
    
           **bridge=**_< bridgename>_:_< ethnames>_
               Setup bridge <bridgename> with <ethnames>. <ethnames> is a
               comma-separated list of physical (ethernet) interfaces. Bridge
               without parameters assumes bridge=br0:eth0
    
       **NFS**
           **root=**__ <root-dir>__[:_< nfs-options>_]
               mount nfs share from <server-ip>:/<root-dir>, if no server-ip
               is given, use dhcp next_server. If server-ip is an IPv6
               address it has to be put in brackets, e.g. [2001:DB8::1]. NFS
               options can be appended with the prefix ":" or "," and are
               separated by ",".
    
           **root=** nfs:[_< server-ip>_:]__ <root-dir>__[:_< nfs-options>_],
           **root=** nfs4:[_< server-ip>_:]__ <root-dir>__[:_< nfs-options>_],
           **root=**_{dhcp|dhcp6}_
               netroot=dhcp alone directs initrd to look at the DHCP
               root-path where NFS options can be specified.
    
               **Example**
    
                       root-path=<server-ip>:<root-dir>[,<nfs-options>]
                       root-path=nfs:<server-ip>:<root-dir>[,<nfs-options>]
                       root-path=nfs4:<server-ip>:<root-dir>[,<nfs-options>]
    
           **root=**_/dev/nfs_ nfsroot=__ <root-dir>__[:_< nfs-options>_]
               _Deprecated!_ kernel Documentation_/filesystems/nfsroot.txt_
               defines this method. This is supported by dracut, but not
               recommended.
    
           **rd.nfs.domain=**_< NFSv4 domain name>_
               Set the NFSv4 domain name. Will override the settings in
               _/etc/idmap.conf_.
    
           **rd.net.dhcp.retry=**_< cnt>_
               If this option is set, dracut will try to connect via dhcp
               <cnt> times before failing. Default is 1.
    
           **rd.net.timeout.dhcp=**_< arg>_
               If this option is set, dhclient is called with "--timeout
               <arg>".
    
           **rd.net.timeout.iflink=**_< seconds>_
               Wait <seconds> until link shows up. Default is 60 seconds.
    
           **rd.net.timeout.ifup=**_< seconds>_
               Wait <seconds> until link has state "UP". Default is 20
               seconds.
    
           **rd.net.timeout.route=**_< seconds>_
               Wait <seconds> until route shows up. Default is 20 seconds.
    
           **rd.net.timeout.ipv6dad=**_< seconds>_
               Wait <seconds> until IPv6 DAD is finished. Default is 50
               seconds.
    
           **rd.net.timeout.ipv6auto=**_< seconds>_
               Wait <seconds> until IPv6 automatic addresses are assigned.
               Default is 40 seconds.
    
           **rd.net.timeout.carrier=**_< seconds>_
               Wait <seconds> until carrier is recognized. Default is 10
               seconds.
    
       **CIFS**
           **root=** cifs://[_< username>_[:_< password>_]@]_< server-ip>_:_< root-dir>_
                   mount cifs share from <server-ip>:/<root-dir>, if no
               server-ip is given, use dhcp next_server. if server-ip is an
               IPv6 address it has to be put in brackets, e.g. [2001:DB8::1].
               If a username or password are not specified as part of the
               root, then they must be passed on the command line through
               cifsuser/cifspass.
    
                   **Warning**
    
                   Passwords specified on the kernel command line are visible
                   for all users via the file _/proc/cmdline_ and via dmesg or
                   can be sniffed on the network, when using DHCP with DHCP
                   root-path.
    
           **cifsuser** =_< username>_
               Set the cifs username, if not specified as part of the root.
    
           **cifspass** =_< password>_
               Set the cifs password, if not specified as part of the root.
    
                   **Warning**
    
                   Passwords specified on the kernel command line are visible
                   for all users via the file _/proc/cmdline_ and via dmesg or
                   can be sniffed on the network, when using DHCP with DHCP
                   root-path.
    
       **iSCSI**
           **root=** iscsi:[_< username>_:_< password>_[:_< reverse>_:_< password>_]@][_< servername>_]:[_< protocol>_]:[_< port>_][:[_< iscsi_iface_name>_]:[_< netdev_name>_]]:[_< LUN>_]:_< targetname>_
               protocol defaults to "6", LUN defaults to "0". If the
               "servername" field is provided by BOOTP or DHCP, then that
               field is used in conjunction with other associated fields to
               contact the boot server in the Boot stage. However, if the
               "servername" field is not provided, then the "targetname"
               field is then used in the Discovery Service stage in
               conjunction with other associated fields. See rfc4173
               <http://tools.ietf.org/html/rfc4173#section-5>.
    
                   **Warning**
    
                   Passwords specified on the kernel command line are visible
                   for all users via the file _/proc/cmdline_ and via dmesg or
                   can be sniffed on the network, when using DHCP with DHCP
                   root-path.
    
               **Example**
    
                   root=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
    
               If servername is an IPv6 address, it has to be put in
               brackets:
    
               **Example**
    
                   root=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0
    
           **root=**_???_
           **netroot=** iscsi:[_< username>_:_< password>_[:_< reverse>_:_< password>_]@][_< servername>_]:[_< protocol>_]:[_< port>_][:[_< iscsi_iface_name>_]:[_< netdev_name>_]]:[_< LUN>_]:_< targetname>_
           ...
               multiple netroot options allow setting up multiple iscsi
               disks:
    
               **Example**
    
                   root=UUID=12424547
                   netroot=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
                   netroot=iscsi:192.168.50.1::::iqn.2009-06.dracut:target1
    
               If servername is an IPv6 address, it has to be put in
               brackets:
    
               **Example**
    
                   netroot=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0
    
                   **Warning**
    
                   Passwords specified on the kernel command line are visible
                   for all users via the file _/proc/cmdline_ and via dmesg or
                   can be sniffed on the network, when using DHCP with DHCP
                   root-path. You may want to use rd.iscsi.firmware.
    
           **root=**_???_ **rd.iscsi.initiator=**_< initiator>_
           **rd.iscsi.target.name=**_< target name>_  **rd.iscsi.target.ip=**_< target ip>_
           **rd.iscsi.target.port=**_< target port>_ **rd.iscsi.target.group=**_< target_
           _group >_ **rd.iscsi.username=**_< username>_ **rd.iscsi.password=**_< password>_
           **rd.iscsi.in.username=**_< in username>_ **rd.iscsi.in.password=**_< in_
           _password >_
               manually specify all iscsistart parameter (see
               iscsistart --help)
    
                   **Warning**
    
                   Passwords specified on the kernel command line are visible
                   for all users via the file _/proc/cmdline_ and via dmesg or
                   can be sniffed on the network, when using DHCP with DHCP
                   root-path. You may want to use rd.iscsi.firmware.
    
           **root=**_???_ **netroot=** iscsi **rd.iscsi.firmware=1**
               will read the iscsi parameter from the BIOS firmware
    
           **rd.iscsi.login_retry_max=**_< num>_
               maximum number of login retries
    
           **rd.iscsi.param=**_< param>_
               <param> will be passed as "--param <param>" to iscsistart.
               This parameter can be specified multiple times.
    
               **Example**
    
                   "netroot=iscsi rd.iscsi.firmware=1 rd.iscsi.param=node.session.timeo.replacement_timeout=30"
    
               will result in
    
                   iscsistart -b --param node.session.timeo.replacement_timeout=30
    
           **rd.iscsi.ibft rd.iscsi.ibft=1** : Turn on iBFT autoconfiguration for
           the interfaces
    
           **rd.iscsi.mp rd.iscsi.mp=1** : Configure all iBFT interfaces, not only
           used for booting (multipath)
    
           **rd.iscsi.waitnet=0** : Turn off waiting for all interfaces to be up
           before trying to login to the iSCSI targets.
    
           **rd.iscsi.testroute=0** : Turn off checking, if the route to the iSCSI
           target IP is possible before trying to login.
    
           **rd.iscsi.transport=**_< transport_name>_
               _Set the iSCSI transport name (see man:iscsiadm[8,external])._
               _iSCSI offload transports like_ **bnx2i** _don’t need the network to_
               _be up in order to bring up iSCSI connections. This parameter_
               _indicates that network setup can be skipped in the initramfs,_
               _which makes booting with iSCSI offload cards faster and more_
               _reliable. This parameter currently only has an effect for_
               _< transport_name>=bnx2i or <transport_name>=qedi._
    
       **FCoE**
           **rd.fcoe=0**
               disable FCoE and lldpad
    
           **fcoe=**_< edd|interface|MAC>_:_{dcb|nodcb}_ :_{fabric|vn2vn}_
               Try to connect to a FCoE SAN through the NIC specified by
               _< interface>_ or _< MAC>_ or EDD settings. The second argument
               specifies if DCB should be used. The optional third argument
               specifies whether fabric or VN2VN mode should be used. This
               parameter can be specified multiple times.
    
                   **Note**
    
                   letters in the MAC-address must be lowercase!
    
       **NVMf**
           **rd.nonvmf**
               Disable NVMf
    
           **rd.nvmf.nonbft**
               Disable connecting to targets from the NVMe Boot Firmware
               Table. Without this parameter, NBFT connections will take
               precedence over _rd.nvmf.discover_.
    
           **rd.nvmf.nostatic**
               Disable connecting to targets that have been statically
               configured when the initramfs was built. Targets specified
               with rd.nvmf.discover on the kernel command line will still be
               tried.
    
           **rd.nvmf.hostnqn=**_< hostNQN>_
               NVMe host NQN to use
    
           **rd.nvmf.hostid=**_< hostID>_
               NVMe host id to use
    
           **rd.nvmf.discover=**_{rdma|fc|tcp}_ ,_< traddr>_,[_< host_traddr>_],[_< trsvcid>_]
               Discover and connect to a NVMe-over-Fabric controller
               specified by _< traddr>_ and the optionally _< host_traddr>_ or
               _< trsvcid>_. The first argument specifies the transport to use;
               currently only _rdma_ , _fc_ , or _tcp_ are supported. This parameter
               can be specified multiple times.
    
               **Examples**
    
                   rd.nvmf.discover=tcp,192.168.10.10,,4420
                   rd.nvmf.discover=fc,nn-0x201700a05634f5bf:pn-0x201900a05634f5bf,nn-0x200000109b579ef3:pn-0x100000109b579ef3
    
           **rd.nvmf.discover=fc,auto**
               This special syntax determines that Fibre Channel
               autodiscovery is to be used rather than regular NVMe
               discovery. It takes precedence over all other
               _rd.nvmf.discover=_ arguments.
    
       **NBD**
           **root=**???
           **netroot=** nbd:_< server>_:_< port/exportname>_[:_< fstype>_[:_< mountopts>_[:_< nbdopts>_]]]
               mount nbd share from <server>.
    
               NOTE: If "exportname" instead of "port" is given the standard
               port is used. Newer versions of nbd are only supported with
               "exportname".
    
           **root=/dev/root netroot=dhcp** with **dhcp**
           **root-path=** nbd:_< server>_:_< port/exportname>_[:_< fstype>_[:_< mountopts>_[:_< nbdopts>_]]]
               netroot=dhcp alone directs initrd to look at the DHCP
               root-path where NBD options can be specified. This syntax is
               only usable in cases where you are directly mounting the
               volume as the rootfs.
    
               NOTE: If "exportname" instead of "port" is given the standard
               port is used. Newer versions of nbd are only supported with
               "exportname".
    
       **VIRTIOFS**
           **root=** virtiofs:_< mount-tag>_
               mount virtiofs share using the tag <mount-tag>. The tag name
               is arbitrary and must match the tag given in the qemu _-device_
               command.
    
           **rootfstype=** virtiofs **root=**_< mount-tag>_
               mount virtiofs share using the tag <mount-tag>. The tag name
               is arbitrary and must match the tag given in the qemu _-device_
               command.
    
           Both formats are supported by the _virtiofs_ dracut module. See
           https://gitlab.com/virtio-fs/virtiofsd for more information.
    
           **Example**
    
               root=virtiofs:host rw
    
       **DASD**
           **rd.dasd=**....
               same syntax as the kernel module parameter (s390 only). For
               more details on the syntax see the IBM book "Linux on IBM Z
               and IBM LinuxONE - Device Drivers, Features, and Commands"
               https://www.ibm.com/docs/en/linux-on-systems?topic=overview-device-drivers-features-commands.
               This parameter can be specified multiple times.
    
               NOTE: This parameter is no longer handled by dracut itself but
               with the exact same syntax by
               https://github.com/ibm-s390-linux/s390-tools/tree/master/zdev/dracut/95zdev.
    
       **ZFCP**
           **rd.zfcp=**_< zfcp adaptor device bus ID>_,_< WWPN>_,_< FCPLUN>_
               rd.zfcp can be specified multiple times on the kernel command
               line.
    
               NOTE: This parameter is no longer handled by dracut itself but
               with the exact same syntax by
               https://github.com/ibm-s390-linux/s390-tools/tree/master/zdev/dracut/95zdev.
    
           **rd.zfcp=**_< zfcp adaptor device bus ID>_
               If NPIV is enabled and the _allow_lun_scan_ parameter to the
               zfcp module is set to _Y_ then the zfcp driver will be
               initiating a scan internally and the <WWPN> and <FCPLUN>
               parameters can be omitted.
    
               NOTE: This parameter is no longer handled by dracut itself but
               with the exact same syntax by
               https://github.com/ibm-s390-linux/s390-tools/tree/master/zdev/dracut/95zdev.
    
               **Example**
    
                   rd.zfcp=0.0.4000,0x5005076300C213e9,0x5022000000000000
                   rd.zfcp=0.0.4000
    
           **rd.zfcp.conf=0**
               ignore zfcp.conf included in the initramfs
    
       **ZNET**
           **rd.znet=**_< nettype>_,_< subchannels>_,_< options>_
               Activates a channel-attached network interface on s390
               architecture. <nettype> is one of: qeth, lcs, ctc.
               <subchannels> is a comma-separated list of ccw device bus-IDs.
               The list consists of 3 entries with nettype qeth, and 2 for
               other nettype. <options> is a comma-separated list of
               <name>=<value> pairs, where <name> refers to a device sysfs
               attribute to which <value> gets written. rd.znet can be
               specified multiple times on the kernel command line.
    
           **rd.znet_ifname=**_< ifname>_:_< subchannels>_
               Assign network device name <interface> (i.e. "bootnet") to the
               NIC corresponds to the subchannels. This is useful when
               dracut’s default "ifname=" doesn’t work due to device having a
               changing MAC address.
    
               **Example**
    
                   rd.znet=qeth,0.0.0600,0.0.0601,0.0.0602,layer2=1,portname=foo
                   rd.znet=ctc,0.0.0600,0.0.0601,protocol=bar
    
       **Booting live images**
           Dracut offers multiple options for live booted images:
    
               SquashFS (read-only) base filesystem image
                   Note — There are 3 separate overlay types available:
    
                   •   Device-mapper snapshots (the original offering),
    
                   •   Device-mapper thin provisioning snapshots (see
                       _rd.live.overlay.thin, a later offering), and_
    
                   _•_   _OverlayFS based overlay mounts (a more recent_
                       _offering)._
    
                   _Using one of these technologies, the system will provide a_
                   _writable overlay for the base, read-only SquashFS root_
                   _filesystem. These methods enable a relatively fast boot_
                   _and lower RAM usage._
    
                   _With the original Device-mapper snapshot overlay, users_
                   **must be careful** _to avoid writing too many blocks to the_
                   _snapshot device. Once the blocks of the snapshot overlay_
                   _are exhausted, the whole root filesystem becomes read-only_
                   _leading to application failures. The snapshot overlay_
                   _device is marked Overflow, and a difficult recovery is_
                   _required to repair and enlarge the overlay offline._
    
                   _When rd.live.overlay= is not specified for persistent_
                   _overlay storage, or the specified file is not found or_
                   _writable, a Device-mapper snapshot based non-persistent or_
                   _temporary overlay is automatically created as a sparse_
                   _file in RAM of the initramfs. This file will only consume_
                   _content space as required blocks are allocated. This_
                   _snapshot based overlay defaults to an apparent size of 32_
                   _GiB in RAM, and can be adjusted with the_
                   _rd.live.overlay.size= kernel command line option. This_
                   _file is hidden (and appears deleted) when the boot process_
                   _switches out of the initramfs to the main root filesystem_
                   _but its loop device remains connected to the Device-mapper_
                   _snapshot._
    
                   _Even with large Device-mapper overlay files for write_
                   _space, the available root filesystem capacity is limited_
                   _by the total allocated size of the base root filesystem,_
                   _which often provide only a small number of gigabytes of_
                   _free space._
    
                   _This shortage could be remedied by building the root_
                   _filesystem with more allocated free space, or the_
                   _OverlayFS based overlay mount method can be used._
    
                   _When the rd.live.overlay.overlayfs option is specified or_
                   _when rd.live.overlay= points to an appropriate directory_
                   _with a sister at_ /../ovlwork _, then an OverlayFS based_
                   _overlay mount is employed. Such a persistent OverlayFS_
                   _overlay can extend the available root filesystem storage_
                   _up to the capacity of the LiveOS disk device._
    
                   _For non-persistent OverlayFS overlays, the_ /run/overlayfs
                   _directory in the_ /run _tmpfs is used for temporary storage._
                   _This filesystem is typically sized to one half of the RAM_
                   _total in the system._
                   _The command:_ mount -o remount,size=<nbytes> /run _will_
                   _resize this virtual filesystem after booting._
    
                   _The internal SquashFS structure is traditionally expected_
                   _to be:_
    
                       _squashfs.img_          _|_  _SquashFS from LiveCD .iso_
                          _!(mount)_
                          _/LiveOS_
                              _|- rootfs.img_  _|_  _Usually a ext4 filesystem image to mount read-only_
                                   _!(mount)_
                                   _/bin_      _|_  _Base Live root filesystem_
                                   _/boot_     _|_
                                   _/dev_      _|_
                                   _... |_
    
                   _For OverlayFS mount overlays, the internal SquashFS_
                   _structure may be a direct compression of the root_
                   _filesystem:_
    
                       _squashfs.img_          _|_  _SquashFS from LiveCD .iso_
                          _!(mount)_
                          _/bin_               _|_  _Base Live root filesystem_
                          _/boot_              _|_
                          _/dev_               _|_
                          _... |_
    
                   _Dracut uses one of the overlay methods of live booting by_
                   _default. No additional command line options are required_
                   _other than_ **root=**_live: <path to blockdevice> or_
                   **root=**_live: <URL> to specify the location of your squashed_
                   _root filesystem._
    
                   _•_   _The compressed SquashFS image can be copied during_
                       _boot to RAM at_ /run/initramfs/squashed.img _by using_
                       _the_ **rd.live.ram=1** _option._
    
                   _•_   _A device with a persistent overlay can be booted_
                       _read-only by using the_ **rd.live.overlay.readonly** _option_
                       _on the kernel command line. This will either cause a_
                       _temporary, writable overlay to be stacked over a_
                       _read-only snapshot of the root filesystem or the_
                       _OverlayFS mount will use an additional lower layer_
                       _with the root filesystem._
    
               _Uncompressed live filesystem image_
                   _When the live system was installed with the --skipcompress_
                   _option of the livecd-iso-to-disk installation script for_
                   _Live USB devices, the root filesystem image, rootfs.img,_
                   _is expanded on installation and no SquashFS is involved_
                   _during boot._
    
                   _•_   _If_ **rd.live.ram=1** _is used in this situation, the full,_
                       _uncompressed root filesystem is copied during boot to_
                       /run/initramfs/rootfs.img _in the_ /run _tmpfs._
    
                   _•_   _If_ **rd.live.overlay=none** _is provided as a kernel_
                       _command line option, a writable, linear Device-mapper_
                       _target is created on boot with no overlay._
    
               _Writable filesystem image_
                   _The system will retrieve a compressed filesystem image,_
                   _extract it to_ /run/initramfs/fsimg/rootfs.img _, connect it_
                   _to a loop device, create a writable, linear Device-mapper_
                   _target at_ /dev/mapper/live-rw _, and mount that as a_
                   _writable volume at_ /_. More RAM is required during boot but_
                   _the live filesystem is easier to manage if it becomes_
                   _full. Users can make a filesystem image of any size and_
                   _that size will be maintained when the system boots. There_
                   _is no persistence of root filesystem changes between boots_
                   _with this option._
    
                   _The filesystem structure is expected to be:_
    
                       _rootfs.tgz_            _|_  _Compressed tarball containing filesystem image_
                          _!(unpack)_
                          _/rootfs.img_        _|_  _Filesystem image at /run/initramfs/fsimg/_
                             _!(mount)_
                             _/bin_            _|_  _Live filesystem_
                             _/boot_           _|_
                             _/dev_            _|_
                             _... |_
    
                   _To use this boot option, ensure that_ **rd.writable.fsimg=1**
                   _is in your kernel command line and add the_ **root=live: <URL>**
                   _to specify the location of your compressed filesystem_
                   _image tarball or SquashFS image._
    
           **rd.writable.fsimg=**_1_
               _Enables writable filesystem support. The system will boot with_
               _a fully writable (but non-persistent) filesystem without_
               _snapshots (see notes above about available live boot options)._
               _You can use the_ **rootflags** _option to set mount options for the_
               _live filesystem as well (see documentation about rootflags in_
               _the_ **Standard** _section above)_**. This implies that the whole image**
               **is copied to RAM before the boot continues.**
    
                   **Note**
    
                   There must be enough free RAM available to hold the
                   complete image.
    
               This method is very suitable for diskless boots.
    
           **rd.minmem=**_< megabyte>_
               Specify minimum free RAM in MB after copying a live disk image
               into memory. The default is 1024.
    
               This parameter only applies together with the parameters
               rd.writable.fsimg or rd.live.ram.
    
           **root=** live:_< url>_
               Boots a live image retrieved from _< url>_. Requires the dracut
               _livenet_ module. Valid handlers: _http, https, ftp, torrent,_
               _tftp_.
    
               **Examples**
    
                   root=live:http://example.com/liveboot.img
                   root=live:ftp://ftp.example.com/liveboot.img
                   root=live:torrent://example.com/liveboot.img.torrent
    
           **rd.live.debug=** 1
               Enables debug output from the live boot process.
    
           **rd.live.dir=**_< path>_
               Specifies the directory within the boot device where the
               squashfs.img or rootfs.img can be found. By default, this is
               /LiveOS.
    
           **rd.live.squashimg=**_< filename of SquashFS image>_
               Specifies the filename for a SquashFS image of the root
               filesystem. By default, this is _squashfs.img_.
    
           **rd.live.ram=** 1
               Copy the complete image to RAM and use this for booting. This
               is useful when the image resides on, e.g., a DVD which needs
               to be ejected later on.
    
           **rd.live.overlay={**_< devspec>_[:_{ <pathspec>|auto}_]|_none_}
               Manage the usage of a persistent overlay.
    
               •   _< devspec> specifies the path to a device with a mountable_
                   _filesystem._
    
               _•_   _< pathspec> is a path within the <devspec> filesystem to_
                   _either_
    
                   _•_   _a file (that is loop mounted for a Device-mapper_
                       _overlay) or_
    
                   _•_   _a directory (that is symbolically linked to_
                       /run/overlayfs _for a OverlayFS mount overlay). (A_
                       _required sister directory_ /<pathspec>/../ovlwork _is_
                       _automatically made.)_
    
               _•_   _none (the word itself) specifies that no overlay will be_
                   _used, such as when an uncompressed, writable live root_
                   _filesystem is available._
    
               _The above method shall be used to persist the changes made to_
               _the root filesystem specified within the_
               **root=**_live: <path to blockdevice> or_ **root=**_live: <url> device._
    
               _The default pathspec, when_ **:auto** _or no_ **:**_< pathspec> is given,_
               _is_ /<rd.live.dir>/overlay-<label>-<uuid>_, where <label> and_
               _< uuid> are the LABEL and UUID of the filesystem specified by_
               _the_ **root=**_live: <path|url> device._
    
               _If a persistent overlay is detected at the standard LiveOS_
               _path, and rd.live.overlay.overlayfs is not set to 1, the_
               _overlay type (either Device-mapper or OverlayFS) will be_
               _detected and it will be used._
    
               **Examples**
    
                   rd.live.overlay=/dev/sdb1:/persistent-overlay.img
                   rd.live.overlay=UUID=99440c1f-8daa-41bf-b965-b7240a8996f4
    
           **rd.live.overlay.cowfs=**_[btrfs|ext4|xfs]_
               Specifies the filesystem to use when formatting the overlay
               partition. The default is ext4.
    
           **rd.live.overlay.size=**_< size_MiB>_
               Specifies a non-persistent Device-mapper overlay size in MiB.
               The default is _32768_.
    
           **rd.live.overlay.readonly=** 1
               This is used to boot in a read-only mode with a normally
               read-write persistent overlay. With this option,
    
               •   Device-mapper overlays will have an additional,
                   non-persistent, writable snapshot overlay stacked over a
                   read-only snapshot (/dev/mapper/live‑ro) of the base root
                   filesystem and the persistent overlay, or
    
               •   for writable rootfs.img images, the above over a read-only
                   loop device, or
    
               •   an OverlayFS mount will link the persistent overlay
                   directory at /run/overlayfs‑r as an additional read-only
                   lower layer stacked over the base root filesystem, and
                   /run/overlayfs becomes the temporary, writable, upper
                   directory overlay, to complete the bootable root
                   filesystem.
    
           **rd.live.overlay.nouserconfirmprompt=**
               Suppresses the _Using temporary overlay_ blocking prompt that
               asks for a user confirmation before proceeding to boot. This
               allows the boot process to continue to completion without user
               interation.
    
           **rd.live.overlay.reset=** 1
               Specifies that a persistent overlay should be reset on boot.
               All previous root filesystem changes are vacated by this
               action.
    
           **rd.live.overlay.thin=** 1
               Enables the usage of thin snapshots instead of classic dm
               snapshots. The advantage of thin snapshots is that they
               support discards, and will free blocks that are not claimed by
               the filesystem. In this use case, this means that memory is
               given back to the kernel when the filesystem does not claim it
               anymore.
    
           **rd.live.overlay.overlayfs=** 1
               Enables the use of the **OverlayFS** kernel module, if available,
               to provide a copy-on-write union directory for the root
               filesystem. OverlayFS overlays are directories of the files
               that have changed on the read-only base (lower) filesystem.
               The root filesystem is provided through a special overlay type
               mount that merges at least two directories, designated the
               lower and the upper. If an OverlayFS upper directory is not
               present on the boot device, a tmpfs directory will be created
               at /run/overlayfs to provide temporary storage. Persistent
               storage can be provided on vfat or msdos formatted devices by
               supplying the OverlayFS upper directory within an embedded
               filesystem that supports the creation of trusted.* extended
               attributes and provides a valid d_type in readdir responses,
               such as with btrfs, ext4, f2fs, & xfs. On non-vfat-formatted
               devices, a persistent OverlayFS overlay can extend the
               available root filesystem storage up to the capacity of the
               LiveOS disk device.
    
               The **rd.live.overlay.readonly** option, which allows a persistent
               overlayfs to be mounted read-only through a higher level
               transient overlay directory, has been implemented through the
               multiple lower layers feature of OverlayFS.
    
       **ZIPL**
           **rd.zipl=**_< path to blockdevice>_
               Update the dracut commandline with the values found in the
               _dracut-cmdline.conf_ file on the given device. The values are
               merged into the existing commandline values and the udev
               events are regenerated.
    
               **Example**
    
                   rd.zipl=UUID=0fb28157-99e3-4395-adef-da3f7d44835a
    
       **CIO_IGNORE**
           **rd.cio_accept=**_< device-ids>_
               Remove the devices listed in <device-ids> from the default
               cio_ignore kernel command-line settings. <device-ids> is a
               list of comma-separated CCW device ids. The default for this
               value is taken from the _/boot/zipl/active_devices.txt_ file.
    
               **Example**
    
                   rd.cio_accept=0.0.0180,0.0.0800,0.0.0801,0.0.0802
    
       **Plymouth Boot Splash**
           **plymouth.enable=0**
               disable the plymouth bootsplash completely.
    
           **rd.plymouth=0**
               disable the plymouth bootsplash only for the initramfs.
    
       **Kernel keys**
           **masterkey=**_< kernel master key path name>_
               Set the path name of the kernel master key.
    
               **Example**
    
                   masterkey=/etc/keys/kmk-trusted.blob
    
           **masterkeytype=**_< kernel master key type>_
               Set the type of the kernel master key.
    
               **Example**
    
                   masterkeytype=trusted
    
           **evmkey=**_< EVM HMAC key path name>_
               Set the path name of the EVM HMAC key.
    
               **Example**
    
                   evmkey=/etc/keys/evm-trusted.blob
    
           **evmx509=**_< EVM X.509 cert path name>_
               Set the path name of the EVM X.509 certificate.
    
               **Example**
    
                   evmx509=/etc/keys/x509_evm.der
    
           **ecryptfskey=**_< eCryptfs key path name>_
               Set the path name of the eCryptfs key.
    
               **Example**
    
                   ecryptfskey=/etc/keys/ecryptfs-trusted.blob
    
       **Deprecated, renamed Options**
           Here is a list of options and their new replacement.
    
           rd_NO_DM
               rd.dm=0
    
           rd_NO_MDADMCONF
               rd.md.conf=0
    
           rd_NO_MDIMSM
               rd.md.imsm=0
    
           rd_NO_MD
               rd.md=0
    
           rd_MD_UUID
               rd.md.uuid
    
           iscsi_initiator
               rd.iscsi.initiator
    
           iscsi_target_name
               rd.iscsi.target.name
    
           iscsi_target_ip
               rd.iscsi.target.ip
    
           iscsi_target_port
               rd.iscsi.target.port
    
           iscsi_target_group
               rd.iscsi.target.group
    
           iscsi_username
               rd.iscsi.username
    
           iscsi_password
               rd.iscsi.password
    
           iscsi_in_username
               rd.iscsi.in.username
    
           iscsi_in_password
               rd.iscsi.in.password
    
           iscsi_firmware
               rd.iscsi.firmware=0
    
           rdudevdebug
               rd.udev.udev_log=debug
    
           rdudevinfo
               rd.udev.udev_log=info
    
           rd.udev.debug
               rd.udev.udev_log=debug
    
           rd.udev.info
               rd.udev.udev_log=info
    
           KEYMAP
               vconsole.keymap
    
           KEYTABLE
               vconsole.keymap
    
           SYSFONT
               vconsole.font
    
           CONTRANS
               vconsole.font.map
    
           UNIMAP
               vconsole.font.unimap
    
           UNICODE
               vconsole.unicode
    
           EXT_KEYMAP
               vconsole.keymap.ext
    
       **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.
    


* * *