dracut.cmdline.7.asc

   1 DRACUT.CMDLINE(7)
   2 =================
   3 :doctype: manpage
   4 :man source:   dracut
   5 :man manual:   dracut
   6
   7 NAME
   8 ----
   9 dracut.cmdline - dracut kernel command line options
  10
  11 DESCRIPTION
  12 -----------
  13 The root device used by the kernel is specified in the boot configuration
  14 file on the kernel command line, as always.
  15
  16 The traditional _root=/dev/sda1_ style device specification is allowed, but not
  17 encouraged. The root device should better be identified by LABEL or UUID. If a
  18 label is used, as in _root=LABEL=<label_of_root>_ the initramfs will search all
  19 available devices for a filesystem with the appropriate label, and mount that
  20 device as the root filesystem. _root=UUID=<uuidnumber>_ will mount the partition
  21 with that UUID as the root filesystem.
  22
  23 In the following all kernel command line parameters, which are processed by
  24 dracut, are described.
  25
  26 "rd.*" parameters mentioned without "=" are boolean parameters. They can be
  27 turned on/off by setting them to {0|1}. If the assignment with "=" is missing
  28 "=1" is implied. For example _rd.info_ can be turned off with _rd.info=0_ or
  29 turned on with _rd.info=1_ or _rd.info_. The last value in the kernel command
  30 line is the value, which is honored.
  31
  32 Standard
  33 ~~~~~~~~
  34 **init=**__<path to real init>__::
  35     specify the path to the init programm to be started after the initramfs has
  36     finished
  37
  38 **root=**__<path to blockdevice>__::
  39     specify the block device to use as the root filesystem.
  40 +
  41 [listing]
  42 .Example
  43 --
  44 root=/dev/sda1
  45 root=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
  46 root=/dev/disk/by-label/Root
  47 root=LABEL=Root
  48 root=/dev/disk/by-uuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
  49 root=UUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
  50 root=PARTUUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
  51 --
  52
  53 **rootfstype=**__<filesystem type>__:: "auto" if not specified.
  54 +
  55 [listing]
  56 .Example
  57 --
  58 rootfstype=ext3
  59 --
  60
  61 **rootflags=**__<mount options>__::
  62     specify additional mount options for the root filesystem. If not set,
  63     _/etc/fstab_ of the real root will be parsed for special mount options and
  64     mounted accordingly.
  65
  66 **ro**::
  67     force mounting _/_ and _/usr_ (if it is a separate device) read-only.  If
  68     none of ro and rw is present, both are mounted according to _/etc/fstab_.
  69
  70 **rw**::
  71     force mounting _/_ and _/usr_ (if it is a separate device) read-write.
  72     See also ro option.
  73
  74 **rootfallback=**__<path to blockdevice>__::
  75     specify the block device to use as the root filesystem, if the normal root
  76     cannot be found. This can only be a simple block device with a simple file
  77     system, for which the filesystem driver is either compiled in, or added
  78     manually to the initramfs. This parameter can be specified multiple times.
  79
  80 **rd.auto** **rd.auto=1**::
  81     enable autoassembly of special devices like cryptoLUKS, dmraid, mdraid or
  82     lvm. Default is off as of dracut version >= 024.
  83
  84 **rd.hostonly=0**::
  85     removes all compiled in configuration of the host system the initramfs image
  86     was built on. This helps booting, if any disk layout changed, especially in
  87     combination with rd.auto or other parameters specifying the layout.
  88
  89 **rd.cmdline=ask**::
  90     prompts the user for additional kernel command line parameters
  91
  92 **rd.fstab=0**::
  93     do not honor special mount options for the root filesystem found in
  94     _/etc/fstab_ of the real root.
  95
  96 **resume=**__<path to resume partition>__::
  97     resume from a swap partition
  98 +
  99 [listing]
 100 .Example
 101 --
 102 resume=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
 103 resume=/dev/disk/by-uuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
 104 resume=UUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
 105 --
 106
 107 **rd.skipfsck**::
 108     skip fsck for rootfs and _/usr_.  If you're mounting _/usr_ read-only and
 109     the init system performs fsck before remount, you might want to use this
 110     option to avoid duplication.
 111
 112 iso-scan/filename
 113 ~~~~~~~~~~~~~~~~~
 114
 115 Using iso-scan/filename with a Fedora/Red Hat/CentOS Live iso should just work
 116 by copying the original kernel cmdline parameters.
 117
 118 [listing]
 119 .Example
 120 --
 121 menuentry 'Live Fedora 20' --class fedora --class gnu-linux --class gnu --class os {
 122     set isolabel=Fedora-Live-LXDE-x86_64-20-1
 123     set isofile="/boot/iso/Fedora-Live-LXDE-x86_64-20-1.iso"
 124     loopback loop $isofile
 125     linux (loop)/isolinux/vmlinuz0 boot=isolinux iso-scan/filename=$isofile root=live:LABEL=$isolabel ro rd.live.image quiet rhgb
 126     initrd (loop)/isolinux/initrd0.img
 127 }
 128 --
 129
 130 Misc
 131 ~~~~
 132 **rd.driver.blacklist=**__<drivername>__[,__<drivername>__,...]::
 133     do not load kernel module <drivername>. This parameter can be specified
 134     multiple times.
 135
 136 **rd.driver.pre=**__<drivername>__[,__<drivername>__,...]::
 137     force loading kernel module <drivername>. This parameter can be specified
 138     multiple times.
 139
 140 **rd.driver.post=**__<drivername>__[,__<drivername>__,...]::
 141     force loading kernel module <drivername> after all automatic loading modules
 142     have been loaded. This parameter can be specified multiple times.
 143
 144 **rd.retry=**__<seconds>__::
 145     specify how long dracut should retry the initqueue to configure devices.
 146     The default is 30 seconds. After 2/3 of the time, degraded raids are force
 147     started. If you have hardware, which takes a very long time to announce its
 148     drives, you might want to extend this value.
 149
 150 **rd.timeout=**__<seconds>__::
 151     specify how long dracut should wait for devices to appear. The
 152     default is '0', which means 'forever'. Note that this timeout
 153     should be longer than rd.retry to allow for proper configuration.
 154
 155 **rd.noverifyssl**::
 156     accept self-signed certificates for ssl downloads.
 157
 158 **rd.ctty=**__<terminal device>__::
 159    specify the controlling terminal for the console.
 160    This is useful, if you have multiple "console=" arguments.
 161
 162 [[dracutkerneldebug]]
 163 Debug
 164 ~~~~~
 165 If you are dropped to an emergency shell, the file
 166 _/run/initramfs/rdsosreport.txt_ is created, which can be saved to a (to be
 167 mounted by hand) partition (usually /boot) or a USB stick. Additional debugging
 168 info can be produced by adding **rd.debug** to the kernel command line.
 169 _/run/initramfs/rdsosreport.txt_ contains all logs and the output of some tools.
 170 It should be attached to any report about dracut problems.
 171
 172 **rd.info**::
 173     print informational output though "quiet" is set
 174
 175 **rd.shell**::
 176     allow dropping to a shell, if root mounting fails
 177
 178 **rd.debug**::
 179     set -x for the dracut shell.
 180     If systemd is active in the initramfs, all output is logged to the systemd
 181     journal, which you can inspect with "journalctl -ab".
 182     If systemd is not active, the logs are written to dmesg and
 183     _/run/initramfs/init.log_.
 184     If "quiet" is set, it also logs to the console.
 185
 186 **rd.memdebug=[0-3]**::
 187     Print memory usage info at various points, set the verbose level from 0 to 3.
 188 +
 189     Higher level means more debugging output:
 190 +
 191 ----
 192     0 - no output
 193     1 - partial /proc/meminfo
 194     2 - /proc/meminfo
 195     3 - /proc/meminfo + /proc/slabinfo
 196 ----
 197
 198 **rd.break**::
 199     drop to a shell at the end
 200
 201 **rd.break=**__{cmdline|pre-udev|pre-trigger|initqueue|pre-mount|mount|pre-pivot|cleanup}__::
 202     drop to a shell on defined breakpoint
 203
 204 **rd.udev.info**::
 205     set udev to loglevel info
 206
 207 **rd.udev.debug**::
 208     set udev to loglevel debug
 209
 210 I18N
 211 ~~~~
 212 **rd.vconsole.keymap=**__<keymap base file name>__::
 213     keyboard translation table loaded by loadkeys; taken from keymaps directory;
 214     will be written as KEYMAP to _/etc/vconsole.conf_ in the initramfs.
 215 +
 216 [listing]
 217 .Example
 218 --
 219 rd.vconsole.keymap=de-latin1-nodeadkeys
 220 --
 221
 222 **rd.vconsole.keymap.ext=**__<list of keymap base file names>__::
 223     list of extra keymaps to bo loaded (sep. by space); will be written as
 224     EXT_KEYMAP to _/etc/vconsole.conf_ in the initramfs
 225
 226 **rd.vconsole.unicode**::
 227     boolean, indicating UTF-8 mode; will be written as UNICODE to
 228     _/etc/vconsole.conf_ in the initramfs
 229
 230 **rd.vconsole.font=**__<font base file name>__::
 231     console font; taken from consolefonts directory; will be written as FONT to
 232     _/etc/vconsole.conf_ in the initramfs.
 233 +
 234 [listing]
 235 .Example
 236 --
 237 rd.vconsole.font=LatArCyrHeb-16
 238 --
 239
 240 **rd.vconsole.font.map=**__<console map base file name>__::
 241     see description of '-m' parameter in setfont manual; taken from consoletrans
 242     directory; will be written as FONT_MAP to _/etc/vconsole.conf_ in the
 243     initramfs
 244
 245 **rd.vconsole.font.unimap=**__<unicode table base file name>__::
 246     see description of '-u' parameter in setfont manual; taken from unimaps
 247     directory; will be written as FONT_UNIMAP to _/etc/vconsole.conf_ in the
 248     initramfs
 249
 250 **rd.locale.LANG=**__<locale>__::
 251     taken from the environment; if no UNICODE is defined we set its value in
 252     basis of LANG value (whether it ends with ".utf8" (or similar) or not); will
 253     be written as LANG to _/etc/locale.conf_ in the initramfs.
 254 +
 255 [listing]
 256 .Example
 257 --
 258 rd.locale.LANG=pl_PL.utf8
 259 --
 260
 261 **rd.locale.LC_ALL=**__<locale>__::
 262     taken from the environment; will be written as LC_ALL to _/etc/locale.conf_
 263     in the initramfs
 264
 265 LVM
 266 ~~~
 267 **rd.lvm=0**::
 268     disable LVM detection
 269
 270 **rd.lvm.vg=**__<volume group name>__::
 271     only activate the volume groups with the given name. rd.lvm.vg can be
 272     specified multiple times on the kernel command line.
 273
 274 **rd.lvm.lv=**__<logical volume name>__::
 275     only activate the logical volumes with the given name. rd.lvm.lv can be
 276     specified multiple times on the kernel command line.
 277
 278 **rd.lvm.conf=0**::
 279     remove any _/etc/lvm/lvm.conf_, which may exist in the initramfs
 280
 281 crypto LUKS
 282 ~~~~~~~~~~~
 283 **rd.luks=0**::
 284     disable crypto LUKS detection
 285
 286 **rd.luks.uuid=**__<luks uuid>__::
 287     only activate the LUKS partitions with the given UUID. Any "luks-" of the
 288     LUKS UUID is removed before comparing to _<luks uuid>_.
 289     The comparisons also matches, if _<luks uuid>_ is only the beginning of the
 290     LUKS UUID, so you don't have to specify the full UUID.
 291     This parameter can be specified multiple times.
 292
 293 **rd.luks.allow-discards=**__<luks uuid>__::
 294     Allow  using  of discards (TRIM) requests for LUKS partitions with the given
 295     UUID. Any "luks-" of the LUKS UUID is removed before comparing to
 296     _<luks uuid>_. The comparisons also matches, if _<luks uuid>_ is only the
 297     beginning of the LUKS UUID, so you don't have to specify the full UUID.
 298     This parameter can be specified multiple times.
 299
 300 **rd.luks.allow-discards**::
 301     Allow  using  of discards (TRIM) requests on all LUKS partitions.
 302
 303 **rd.luks.crypttab=0**::
 304     do not check, if LUKS partition is in _/etc/crypttab_
 305
 306 crypto LUKS - key on removable device support
 307 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 308 **rd.luks.key=**__<keypath>__:__<keydev>__:__<luksdev>__::
 309     _keypath_ is a path to key file to look for. It's REQUIRED. When _keypath_
 310     ends with '.gpg' it's considered to be key encrypted symmetrically with GPG.
 311     You will be prompted for password on boot. GPG support comes with
 312     'crypt-gpg' module which needs to be added explicitly.
 313 +
 314 _keydev_ is a device on which key file resides. It might be kernel name of
 315 devices (should start with "/dev/"), UUID (prefixed with "UUID=") or label
 316 (prefix with "LABEL="). You don't have to specify full UUID. Just its beginning
 317 will suffice, even if its ambiguous. All matching devices will be probed.
 318 This parameter is recommended, but not required. If not present, all block
 319 devices will be probed, which may significantly increase boot time.
 320 +
 321 If _luksdev_ is given, the specified key will only be applied for that LUKS
 322 device. Possible values are the same as for _keydev_. Unless you have several
 323 LUKS devices, you don't have to specify this parameter. The simplest usage is:
 324 +
 325 [listing]
 326 .Example
 327 --
 328 rd.luks.key=/foo/bar.key
 329 --
 330 +
 331 As you see, you can skip colons in such a case.
 332 +
 333 [NOTE]
 334 ===============================
 335 dracut pipes key to cryptsetup with _-d -_ argument, therefore you need to pipe
 336 to crypsetup luksFormat with _-d -_, too!
 337
 338 Here follows example for key encrypted with GPG:
 339
 340 [listing]
 341 --
 342 gpg --quiet --decrypt rootkey.gpg | \
 343 cryptsetup -d - -v --cipher serpent-cbc-essiv:sha256 \
 344 --key-size 256 luksFormat /dev/sda3
 345 --
 346
 347 If you use plain keys, just add path to _-d_ option:
 348
 349 [listing]
 350 --
 351 cryptsetup -d rootkey.key -v --cipher serpent-cbc-essiv:sha256 \
 352  --key-size 256 luksFormat /dev/sda3
 353 --
 354 ===============================
 355
 356 MD RAID
 357 ~~~~~~~
 358 **rd.md=0**::
 359     disable MD RAID detection
 360
 361 **rd.md.imsm=0**::
 362     disable MD RAID for imsm/isw raids, use DM RAID instead
 363
 364 **rd.md.ddf=0**::
 365     disable MD RAID for SNIA ddf raids, use DM RAID instead
 366
 367 **rd.md.conf=0**::
 368     ignore mdadm.conf included in initramfs
 369
 370 **rd.md.waitclean=1**::
 371     wait for any resync, recovery, or reshape activity to finish before
 372     continuing
 373
 374 **rd.md.uuid=**__<md raid uuid>__::
 375     only activate the raid sets with the given UUID. This parameter can be
 376     specified multiple times.
 377
 378 DM RAID
 379 ~~~~~~~
 380 **rd.dm=0**::
 381     disable DM RAID detection
 382
 383 **rd.dm.uuid=**__<dm raid uuid>__::
 384    only activate the raid sets with the given UUID. This parameter can be
 385    specified multiple times.
 386
 387 MULTIPATH
 388 ~~~~~~~~~
 389 **rd.multipath=0**::
 390    disable multipath detection
 391
 392 FIPS
 393 ~~~~
 394 **rd.fips**::
 395     enable FIPS
 396
 397 **boot=**__<boot device>__::
 398     specify the device, where /boot is located.
 399 +
 400 [listing]
 401 .Example
 402 --
 403 boot=/dev/sda1
 404 boot=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
 405 boot=UUID=<uuid>
 406 boot=LABEL=<label>
 407 --
 408
 409 **rd.fips.skipkernel**::
 410     skip checksum check of the kernel image. Useful, if the kernel image is not
 411     in a separate boot partition.
 412
 413 Network
 414 ~~~~~~~
 415
 416 [IMPORTANT]
 417 =====================
 418 It is recommended to either bind an interface to a MAC with the **ifname**
 419 argument, or to use the systemd-udevd predictable network interface names.
 420
 421 Predictable network interface device names based on:
 422
 423 - firmware/bios-provided index numbers for on-board devices
 424 - firmware-provided pci-express hotplug slot index number
 425 - physical/geographical location of the hardware
 426 - the interface's MAC address
 427
 428 See:
 429 http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames
 430
 431 Two character prefixes based on the type of interface:
 432
 433 en:: ethernet
 434 wl:: wlan
 435 ww:: wwan
 436
 437 Type of names:
 438
 439 o<index>:: on-board device index number
 440 s<slot>[f<function>][d<dev_id>]:: hotplug slot index number
 441 x<MAC>:: MAC address
 442 [P<domain>]p<bus>s<slot>[f<function>][d<dev_id>]:: PCI geographical location
 443 [P<domain>]p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]:: USB port number chain
 444
 445 All multi-function PCI devices will carry the [f<function>] number in the
 446 device name, including the function 0 device.
 447
 448 When using PCI geography, The PCI domain is only prepended when it is not 0.
 449
 450 For USB devices the full chain of port numbers of hubs is composed. If the
 451 name gets longer than the maximum number of 15 characters, the name is not
 452 exported.
 453 The usual USB configuration == 1 and interface == 0 values are suppressed.
 454
 455 PCI ethernet card with firmware index "1"::
 456 * eno1
 457
 458 PCI ethernet card in hotplug slot with firmware index number::
 459 * ens1
 460
 461 PCI ethernet multi-function card with 2 ports::
 462 * enp2s0f0
 463 * enp2s0f1
 464
 465 PCI wlan card::
 466 * wlp3s0
 467
 468 USB built-in 3G modem::
 469 * wwp0s29u1u4i6
 470
 471 USB Android phone::
 472 * enp0s29u1u2
 473 =====================
 474
 475 **ip=**__{dhcp|on|any|dhcp6|auto6}__::
 476     dhcp|on|any::: get ip from dhcp server from all interfaces. If root=dhcp,
 477     loop sequentially through all interfaces (eth0, eth1, ...) and use the first
 478     with a valid DHCP root-path.
 479
 480     auto6::: IPv6 autoconfiguration
 481
 482     dhcp6::: IPv6 DHCP
 483
 484 **ip=**__<interface>__:__{dhcp|on|any|dhcp6|auto6}__[:[__<mtu>__][:__<macaddr>__]]::
 485     This parameter can be specified multiple times.
 486 +
 487 =====================
 488 dhcp|on|any|dhcp6::: get ip from dhcp server on a specific interface
 489 auto6::: do IPv6 autoconfiguration
 490 <macaddr>::: optionally **set** <macaddr> on the <interface>. This
 491 cannot be used in conjunction with the **ifname** argument for the
 492 same <interface>.
 493 =====================
 494
 495 **ip=**__<client-IP>__:[__<peer>__]:__<gateway-IP>__:__<netmask>__:__<client_hostname>__:__<interface>__:__{none|off|dhcp|on|any|dhcp6|auto6|ibft}__:[:[__<mtu>__][:__<macaddr>__]]::
 496     explicit network configuration. If you want do define a IPv6 address, put it
 497     in brackets (e.g. [2001:DB8::1]). This parameter can be specified multiple
 498     times. __<peer>__ is optional and is the address of the remote endpoint
 499     for pointopoint interfaces and it may be followed by a slash and a decimal
 500     number, encoding the network prefix length.
 501 +
 502 =====================
 503 <macaddr>::: optionally **set** <macaddr> on the <interface>. This
 504 cannot be used in conjunction with the **ifname** argument for the
 505 same <interface>.
 506 =====================
 507
 508 **ip=**__<client-IP>__:[__<peer>__]:__<gateway-IP>__:__<netmask>__:__<client_hostname>__:__<interface>__:__{none|off|dhcp|on|any|dhcp6|auto6|ibft}__[:[__<dns1>__][:__<dns2>__]]::
 509     explicit network configuration. If you want do define a IPv6 address, put it
 510     in brackets (e.g. [2001:DB8::1]). This parameter can be specified multiple
 511     times. __<peer>__ is optional and is the address of the remote endpoint
 512     for pointopoint interfaces and it may be followed by a slash and a decimal
 513     number, encoding the network prefix length.
 514
 515 **ifname=**__<interface>__:__<MAC>__::
 516     Assign network device name <interface> (ie "bootnet") to the NIC with
 517     MAC <MAC>.
 518 +
 519 WARNING: Do **not** use the default kernel naming scheme for the interface name,
 520 as it can conflict with the kernel names. So, don't use "eth[0-9]+" for the
 521 interface name. Better name it "bootnet" or "bluesocket".
 522
 523 **rd.route=**__<net>__/__<netmask>__:__<gateway>__[:__<interface>__]::
 524     Add a static route with route options, which are separated by a colon.
 525     IPv6 addresses have to be put in brackets.
 526 +
 527 [listing]
 528 .Example
 529 --
 530     rd.route=192.168.200.0/24:192.168.100.222:ens10
 531     rd.route=192.168.200.0/24:192.168.100.222
 532     rd.route=192.168.200.0/24::ens10
 533     rd.route=[2001:DB8:3::/8]:[2001:DB8:2::1]:ens10
 534 --
 535
 536 **bootdev=**__<interface>__::
 537     specify network interface to use routing and netroot information from.
 538     Required if multiple ip= lines are used.
 539
 540 **BOOTIF=**__<MAC>__::
 541     specify network interface to use routing and netroot information from.
 542
 543 **rd.bootif=0**::
 544     Disable BOOTIF parsing, which is provided by PXE
 545
 546 **nameserver=**__<IP>__ [**nameserver=**__<IP>__ ...]::
 547     specify nameserver(s) to use
 548
 549 **biosdevname=0**::
 550     boolean, turn off biosdevname network interface renaming
 551
 552 **rd.neednet=1**::
 553     boolean, bring up network even without netroot set
 554
 555 **vlan=**__<vlanname>__:__<phydevice>__::
 556     Setup vlan device named <vlanname> on <phydeivce>.
 557     We support the four styles of vlan names: VLAN_PLUS_VID (vlan0005),
 558     VLAN_PLUS_VID_NO_PAD (vlan5), DEV_PLUS_VID (eth0.0005),
 559     DEV_PLUS_VID_NO_PAD (eth0.5)
 560
 561 **bond=**__<bondname>__[:__<bondslaves>__:[:__<options>__]]::
 562     Setup bonding device <bondname> on top of <bondslaves>.
 563     <bondslaves> is a comma-separated list of physical (ethernet) interfaces.
 564     <options> is a comma-separated list on bonding options (modinfo bonding for
 565     details) in format compatible with initscripts. If <options> includes
 566     multi-valued arp_ip_target option, then its values should be separated by
 567     semicolon. Bond without parameters assumes
 568     bond=bond0:eth0,eth1:mode=balance-rr
 569
 570 **team=**__<teammaster>__:__<teamslaves>__::
 571     Setup team device <teammaster> on top of <teamslaves>.
 572     <teamslaves> is a comma-separated list of physical (ethernet) interfaces.
 573
 574 **bridge=**__<bridgename>__:__<ethnames>__::
 575     Setup bridge <bridgename> with <ethnames>. <ethnames> is a comma-separated
 576     list of physical (ethernet) interfaces. Bridge without parameters assumes
 577     bridge=br0:eth0
 578
 579 NFS
 580 ~~~
 581 **root=**\[_<server-ip>_:]__<root-dir>__[:__<nfs-options>__]::
 582     mount nfs share from <server-ip>:/<root-dir>, if no server-ip is given, use
 583     dhcp next_server. If server-ip is an IPv6 address it has to be put in
 584     brackets, e.g. [2001:DB8::1]. NFS options can be appended with the prefix
 585     ":" or "," and are seperated by ",".
 586
 587 **root=**nfs:\[_<server-ip>_:]__<root-dir>__[:__<nfs-options>__], **root=**nfs4:\[_<server-ip>_:]__<root-dir>__[:__<nfs-options>__], **root=**__{dhcp|dhcp6}__::
 588     root=dhcp alone directs initrd to look at the DHCP root-path where NFS
 589     options can be specified.
 590 +
 591 [listing]
 592 .Example
 593 --
 594     root-path=<server-ip>:<root-dir>[,<nfs-options>]
 595     root-path=nfs:<server-ip>:<root-dir>[,<nfs-options>]
 596     root-path=nfs4:<server-ip>:<root-dir>[,<nfs-options>]
 597 --
 598
 599 **root=**_/dev/nfs_ nfsroot=\[_<server-ip>_:]__<root-dir>__[:__<nfs-options>__]::
 600     _Deprecated!_ kernel Documentation_/filesystems/nfsroot.txt_ defines this
 601     method. This is supported by dracut, but not recommended.
 602
 603 **rd.nfs.domain=**__<NFSv4 domain name>__::
 604     Set the NFSv4 domain name. Will overwrite the settings in _/etc/idmap.conf_.
 605
 606 CIFS
 607 ~~~
 608 **root=**cifs://[__<username>__[:__<password>__]@]__<server-ip>__:__<root-dir>__::
 609     mount cifs share from <server-ip>:/<root-dir>, if no server-ip is given, use
 610     dhcp next_server. if server-ip is an IPv6 address it has to be put in
 611     brackets, e.g. [2001:DB8::1]. If a username or password are not specified
 612 as part of the root, then they must be passed on the command line through
 613 cifsuser/cifspass.
 614 +
 615 WARNING: Passwords specified on the kernel command line are visible for all
 616 users via the file _/proc/cmdline_ and via dmesg or can be sniffed on the
 617 network, when using DHCP with DHCP root-path.
 618
 619 **cifsuser**=__<username>__::
 620     Set the cifs username, if not specified as part of the root.
 621
 622 **cifspass**=__<password>__::
 623     Set the cifs password, if not specified as part of the root.
 624 +
 625 WARNING: Passwords specified on the kernel command line are visible for all
 626 users via the file _/proc/cmdline_ and via dmesg or can be sniffed on the
 627 network, when using DHCP with DHCP root-path.
 628
 629 iSCSI
 630 ~~~~~
 631 **root=**iscsi:[__<username>__:__<password>__[:__<reverse>__:__<password>__]@][__<servername>__]:[__<protocol>__]:[__<port>__][:[__<iscsi_iface_name>__]:[__<netdev_name>__]]:[__<LUN>__]:__<targetname>__::
 632     protocol defaults to "6", LUN defaults to "0". If the "servername" field is
 633     provided by BOOTP or DHCP, then that field is used in conjunction with other
 634     associated fields to contact the boot server in the Boot stage. However, if
 635     the "servername" field is not provided, then the "targetname" field is then
 636     used in the Discovery Service stage in conjunction with other associated
 637     fields. See
 638     link:$$http://tools.ietf.org/html/rfc4173#section-5$$[rfc4173].
 639 +
 640 WARNING: Passwords specified on the kernel command line are visible for all
 641 users via the file _/proc/cmdline_ and via dmesg or can be sniffed on the
 642 network, when using DHCP with DHCP root-path.
 643 +
 644 [listing]
 645 .Example
 646 --
 647 root=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
 648 --
 649 +
 650 If servername is an IPv6 address, it has to be put in brackets:
 651 +
 652 [listing]
 653 .Example
 654 --
 655 root=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0
 656 --
 657
 658 **root=**__???__ **netroot=**iscsi:[__<username>__:__<password>__[:__<reverse>__:__<password>__]@][__<servername>__]:[__<protocol>__]:[__<port>__][:[__<iscsi_iface_name>__]:[__<netdev_name>__]]:[__<LUN>__]:__<targetname>__ ...::
 659     multiple netroot options allow setting up multiple iscsi disks:
 660 +
 661 [listing]
 662 .Example
 663 --
 664 root=UUID=12424547
 665 netroot=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
 666 netroot=iscsi:192.168.50.1::::iqn.2009-06.dracut:target1
 667 --
 668 +
 669 If servername is an IPv6 address, it has to be put in brackets:
 670 +
 671 [listing]
 672 .Example
 673 --
 674 netroot=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0
 675 --
 676 +
 677 WARNING: Passwords specified on the kernel command line are visible for all
 678 users via the file _/proc/cmdline_ and via dmesg or can be sniffed on the
 679 network, when using DHCP with DHCP root-path.
 680 You may want to use rd.iscsi.firmware.
 681
 682 **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>__::
 683     manually specify all iscsistart parameter (see **+iscsistart --help+**)
 684 +
 685 WARNING: Passwords specified on the kernel command line are visible for all
 686 users via the file _/proc/cmdline_ and via dmesg or can be sniffed on the
 687 network, when using DHCP with DHCP root-path.
 688 You may want to use rd.iscsi.firmware.
 689
 690 **root=**_???_ **netroot=**iscsi **rd.iscsi.firmware=1**::
 691  will read the iscsi parameter from the BIOS firmware
 692
 693 **rd.iscsi.param=**__<param>__::
 694     <param> will be passed as "--param <param>" to iscsistart.
 695     This parameter can be specified multiple times.
 696 +
 697 [listing]
 698 .Example
 699 --
 700 "netroot=iscsi rd.iscsi.firmware=1 rd.iscsi.param=node.session.timeo.replacement_timeout=30"
 701 --
 702 +
 703 will result in
 704 +
 705 [listing]
 706 --
 707 iscsistart -b --param node.session.timeo.replacement_timeout=30
 708 --
 709
 710 **rd.iscsi.ibft** **rd.iscsi.ibft=1**:
 711     Turn on iBFT autoconfiguration for the interfaces
 712
 713 FCoE
 714 ~~~~
 715 **fcoe=**__<edd|interface|MAC>__:__{dcb|nodcb}__::
 716     Try to connect to a FCoE SAN through the NIC specified by _<interface>_ or
 717     _<MAC>_ or EDD settings. For the second argument, currently only nodcb is
 718     supported. This parameter can be specified multiple times.
 719 +
 720 NOTE: letters in the MAC-address must be lowercase!
 721
 722 NBD
 723 ~~~
 724 **root=**??? **netroot=**nbd:__<server>__:__<port>__[:__<fstype>__[:__<mountopts>__[:__<nbdopts>__]]]::
 725     mount nbd share from <server>
 726
 727 **root=dhcp** with **dhcp** **root-path=**nbd:__<server>__:__<port>__[:__<fstype>__[:__<mountopts>__[:__<nbdopts>__]]]::
 728     root=dhcp alone directs initrd to look at the DHCP root-path where NBD
 729     options can be specified. This syntax is only usable in cases where you are
 730     directly mounting the volume as the rootfs.
 731
 732 DASD
 733 ~~~~
 734 **rd.dasd=**....::
 735     same syntax as the kernel module parameter (s390 only)
 736
 737 ZFCP
 738 ~~~~
 739 **rd.zfcp=**__<zfcp adaptor device bus ID>__,__<WWPN>__,__<FCPLUN>__::
 740     rd.zfcp can be specified multiple times on the kernel command line.
 741 +
 742 [listing]
 743 .Example
 744 --
 745 rd.zfcp=0.0.4000,0x5005076300C213e9,0x5022000000000000
 746 --
 747
 748 **rd.zfcp.conf=0**::
 749     ignore zfcp.conf included in the initramfs
 750
 751 ZNET
 752 ~~~~
 753 **rd.znet=**__<nettype>__,__<subchannels>__,__<options>__::
 754     rd.znet can be specified multiple times on the kernel command line.
 755 +
 756 [listing]
 757 .Example
 758 --
 759 rd.znet=qeth,0.0.0600,0.0.0601,0.0.0602,layer2=1,portname=foo
 760 rd.znet=ctc,0.0.0600,0.0.0601,protocol=bar
 761 --
 762
 763 Booting live images
 764 ~~~~~~~~~~~~~~~~~~~
 765 Dracut offers multiple options for live booted images:
 766
 767 =====================
 768 squashfs with read-only filesystem image::: The system will boot with a read
 769 only filesystem from the squashfs and apply a writable device mapper snapshot
 770 over the read only filesystem.  Using this method ensures a relatively fast
 771 boot and lower RAM usage. Users **must be careful** to avoid writing too many
 772 blocks to the snapshot volume.  Once the blocks of the snapshot are exhaused,
 773 the live filesystem becomes unusable and requires a reboot.
 774 +
 775 The filesystem structure is expected to be:
 776 +
 777 [listing]
 778 --
 779 squashfs.img          |  Squashfs downloaded via network
 780    !(mount)
 781    /LiveOS
 782        |- ext3fs.img  |  Filesystem image to mount read-only
 783             !(mount)
 784             /bin      |  Live filesystem
 785             /boot     |
 786             /dev      |
 787             ...       |
 788 --
 789 +
 790 Dracut uses this method of live booting by default.  No additional command line
 791 options are required other than **root=live:<URL>** to specify the location
 792 of your squashed filesystem.
 793 +
 794 writable filesystem image::: The system will retrieve a compressed filesystem
 795 image, connect it to a loopback device, and mount it as a writable volume.  More
 796 RAM is required during boot but the live filesystem is easier to manage if it
 797 becomes full.  Users can make a filesystem image of any size and that size will
 798 be maintained when the system boots.
 799 +
 800 The filesystem structure is expected to be:
 801 +
 802 [listing]
 803 --
 804 rootfs.tgz            |  Compressed tarball containing fileystem image
 805    !(unpack)
 806    /rootfs.img        |  Filesystem image
 807       !(mount)
 808       /bin            |  Live filesystem
 809       /boot           |
 810       /dev            |
 811       ...             |
 812 --
 813 +
 814 To use this boot option, ensure that **rd.writable_fsimg=1** is in your kernel
 815 command line and add the **root=live:<URL>** to specify the location
 816 of your compressed filesystem image tarball.
 817 =====================
 818
 819 **root=**live:__<url>__::
 820 Boots a live image retrieved from __<url>__.  Valid handlers: __http, https, ftp, torrent, tftp__.
 821 +
 822 [listing]
 823 .Example
 824 --
 825 root=live:http://example.com/liveboot.img
 826 root=live:ftp://ftp.example.com/liveboot.img
 827 root=live:torrent://example.com/liveboot.img.torrent
 828 --
 829
 830 **rd.live.debug=**1::
 831 Enables debug output from the live boot process.
 832
 833 **rd.live.dir=**__<path>__::
 834 Specifies the directory within the squashfs where the ext3fs.img or rootfs.img
 835 can be found.  By default, this is __LiveOS__.
 836
 837 **rd.live.ram=**1::
 838 Copy the complete image to RAM and use this for booting. This is useful
 839 when the image resides on i.e. a DVD which needs to be ejected later on.
 840
 841 **rd.live.overlay.thin=**1::
 842 Enables the usage of thin snapshots instead of classic dm snapshots.
 843 The advantage of thin snapshots is, that they support discards, and will free
 844 blocks which are not claimed by the filesystem. In this use case this means,
 845 that memory is given back to the kernel, when the filesystem does not claim it
 846 anymore.
 847
 848 **rd.writable.fsimg=**1::
 849 Enables writable filesystem support.  The system will boot with a fully
 850 writable filesystem without snapshots __(see notes above about available live boot options)__.
 851 You can use the **rootflags** option to set mount options for the live
 852 filesystem as well __(see documentation about rootflags in the **Standard** section above)__.
 853 This implies that the whole image is copied to RAM before the boot continues.
 854 +
 855 NOTE: There must be enough free RAM available to hold the complete image.
 856 +
 857 This method is very suitable for diskless boots.
 858
 859
 860 Plymouth Boot Splash
 861 ~~~~~~~~~~~~~~~~~~~~
 862 **plymouth.enable=0**::
 863     disable the plymouth bootsplash completely.
 864
 865 **rd.plymouth=0**::
 866     disable the plymouth bootsplash only for the initramfs.
 867
 868 Kernel keys
 869 ~~~~~~~~~~~
 870 **masterkey=**__<kernel master key path name>__::
 871     Set the path name of the kernel master key.
 872 +
 873 [listing]
 874 .Example
 875 --
 876 masterkey=/etc/keys/kmk-trusted.blob
 877 --
 878
 879 **masterkeytype=**__<kernel master key type>__::
 880     Set the type of the kernel master key.
 881 +
 882 [listing]
 883 .Example
 884 --
 885 masterkeytype=trusted
 886 --
 887
 888 **evmkey=**__<EVM key path name>__::
 889     Set the path name of the EVM key.
 890 +
 891 [listing]
 892 .Example
 893 --
 894 evmkey=/etc/keys/evm-trusted.blob
 895 --
 896
 897 **ecryptfskey=**__<eCryptfs key path name>__::
 898     Set the path name of the eCryptfs key.
 899 +
 900 [listing]
 901 .Example
 902 --
 903 ecryptfskey=/etc/keys/ecryptfs-trusted.blob
 904 --
 905
 906 Deprecated, renamed Options
 907 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 908 Here is a list of options, which were used in dracut prior to version 008, and
 909 their new replacement.
 910
 911 rdbreak:: rd.break
 912
 913 rd_CCW:: rd.ccw
 914
 915 rd_DASD_MOD:: rd.dasd
 916
 917 rd_DASD:: rd.dasd
 918
 919 rdinitdebug rdnetdebug:: rd.debug
 920
 921 rd_NO_DM:: rd.dm=0
 922
 923 rd_DM_UUID:: rd.dm.uuid
 924
 925 rdblacklist:: rd.driver.blacklist
 926
 927 rdinsmodpost:: rd.driver.post
 928
 929 rdloaddriver:: rd.driver.pre
 930
 931 rd_NO_FSTAB:: rd.fstab=0
 932
 933 rdinfo:: rd.info
 934
 935 check:: rd.live.check
 936
 937 rdlivedebug:: rd.live.debug
 938
 939 live_dir:: rd.live.dir
 940
 941 liveimg:: rd.live.image
 942
 943 overlay:: rd.live.overlay
 944
 945 readonly_overlay:: rd.live.overlay.readonly
 946
 947 reset_overlay:: rd.live.overlay.reset
 948
 949 live_ram:: rd.live.ram
 950
 951 rd_NO_CRYPTTAB:: rd.luks.crypttab=0
 952
 953 rd_LUKS_KEYDEV_UUID:: rd.luks.keydev.uuid
 954
 955 rd_LUKS_KEYPATH:: rd.luks.keypath
 956
 957 rd_NO_LUKS:: rd.luks=0
 958
 959 rd_LUKS_UUID:: rd.luks.uuid
 960
 961 rd_NO_LVMCONF:: rd.lvm.conf
 962
 963 rd_LVM_LV:: rd.lvm.lv
 964
 965 rd_NO_LVM:: rd.lvm=0
 966
 967 rd_LVM_SNAPSHOT:: rd.lvm.snapshot
 968
 969 rd_LVM_SNAPSIZE:: rd.lvm.snapsize
 970
 971 rd_LVM_VG:: rd.lvm.vg
 972
 973 rd_NO_MDADMCONF:: rd.md.conf=0
 974
 975 rd_NO_MDIMSM:: rd.md.imsm=0
 976
 977 rd_NO_MD:: rd.md=0
 978
 979 rd_MD_UUID:: rd.md.uuid
 980
 981 rd_NO_MULTIPATH: rd.multipath=0
 982
 983 rd_NFS_DOMAIN:: rd.nfs.domain
 984
 985 iscsi_initiator:: rd.iscsi.initiator
 986
 987 iscsi_target_name:: rd.iscsi.target.name
 988
 989 iscsi_target_ip:: rd.iscsi.target.ip
 990
 991 iscsi_target_port:: rd.iscsi.target.port
 992
 993 iscsi_target_group:: rd.iscsi.target.group
 994
 995 iscsi_username:: rd.iscsi.username
 996
 997 iscsi_password:: rd.iscsi.password
 998
 999 iscsi_in_username:: rd.iscsi.in.username
1000
1001 iscsi_in_password:: rd.iscsi.in.password
1002
1003 iscsi_firmware:: rd.iscsi.firmware=0
1004
1005 rd_NO_PLYMOUTH:: rd.plymouth=0
1006
1007 rd_retry:: rd.retry
1008
1009 rdshell:: rd.shell
1010
1011 rd_NO_SPLASH:: rd.splash
1012
1013 rdudevdebug:: rd.udev.debug
1014
1015 rdudevinfo:: rd.udev.info
1016
1017 rd_NO_ZFCPCONF:: rd.zfcp.conf=0
1018
1019 rd_ZFCP:: rd.zfcp
1020
1021 rd_ZNET:: rd.znet
1022
1023 KEYMAP:: vconsole.keymap
1024
1025 KEYTABLE:: vconsole.keymap
1026
1027 SYSFONT:: vconsole.font
1028
1029 CONTRANS:: vconsole.font.map
1030
1031 UNIMAP:: vconsole.font.unimap
1032
1033 UNICODE:: vconsole.unicode
1034
1035 EXT_KEYMAP:: vconsole.keymap.ext
1036
1037 Configuration in the Initramfs
1038 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1039 _/etc/conf.d/_::
1040     Any files found in _/etc/conf.d/_ will be sourced in the initramfs to
1041     set initial values. Command line options will override these values
1042     set in the configuration files.
1043
1044 _/etc/cmdline_::
1045     Can contain additional command line options. Deprecated, better use
1046     /etc/cmdline.d/*.conf.
1047
1048 _/etc/cmdline.d/*.conf_::
1049     Can contain additional command line options.
1050
1051 AUTHOR
1052 ------
1053 Harald Hoyer
1054
1055 SEE ALSO
1056 --------
1057 *dracut*(8) *dracut.conf*(5)