1DRACUT.CMDLINE(7)                   dracut                   DRACUT.CMDLINE(7)
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NAME

6       dracut.cmdline - dracut kernel command line options
7

DESCRIPTION

9       The root device used by the kernel is specified in the boot
10       configuration file on the kernel command line, as always.
11
12       The traditional root=/dev/sda1 style device specification is allowed,
13       but not encouraged. The root device should better be identified by
14       LABEL or UUID. If a label is used, as in root=LABEL=<label_of_root> the
15       initramfs will search all available devices for a filesystem with the
16       appropriate label, and mount that device as the root filesystem.
17       root=UUID=<uuidnumber> will mount the partition with that UUID as the
18       root filesystem.
19
20       In the following all kernel command line parameters, which are
21       processed by dracut, are described.
22
23       "rd.*" parameters mentioned without "=" are boolean parameters. They
24       can be turned on/off by setting them to {0|1}. If the assignment with
25       "=" is missing "=1" is implied. For example rd.info can be turned off
26       with rd.info=0 or turned on with rd.info=1 or rd.info. The last value
27       in the kernel command line is the value, which is honored.
28
29   Standard
30       init=<path to real init>
31           specify the path to the init program to be started after the
32           initramfs has finished
33
34       root=<path to blockdevice>
35           specify the block device to use as the root filesystem.
36
37           Example.
38
39               root=/dev/sda1
40               root=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
41               root=/dev/disk/by-label/Root
42               root=LABEL=Root
43               root=/dev/disk/by-uuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
44               root=UUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
45               root=PARTUUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
46
47
48       rootfstype=<filesystem type>
49           "auto" if not specified.
50
51           Example.
52
53               rootfstype=ext3
54
55
56       rootflags=<mount options>
57           specify additional mount options for the root filesystem. If not
58           set, /etc/fstab of the real root will be parsed for special mount
59           options and mounted accordingly.
60
61       ro
62           force mounting / and /usr (if it is a separate device) read-only.
63           If none of ro and rw is present, both are mounted according to
64           /etc/fstab.
65
66       rw
67           force mounting / and /usr (if it is a separate device) read-write.
68           See also ro option.
69
70       rootfallback=<path to blockdevice>
71           specify the block device to use as the root filesystem, if the
72           normal root cannot be found. This can only be a simple block device
73           with a simple file system, for which the filesystem driver is
74           either compiled in, or added manually to the initramfs. This
75           parameter can be specified multiple times.
76
77       rd.auto rd.auto=1
78           enable autoassembly of special devices like cryptoLUKS, dmraid,
79           mdraid or lvm. Default is off as of dracut version >= 024.
80
81       rd.hostonly=0
82           removes all compiled in configuration of the host system the
83           initramfs image was built on. This helps booting, if any disk
84           layout changed, especially in combination with rd.auto or other
85           parameters specifying the layout.
86
87       rd.cmdline=ask
88           prompts the user for additional kernel command line parameters
89
90       rd.fstab=0
91           do not honor special mount options for the root filesystem found in
92           /etc/fstab of the real root.
93
94       resume=<path to resume partition>
95           resume from a swap partition
96
97           Example.
98
99               resume=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
100               resume=/dev/disk/by-uuid/3f5ad593-4546-4a94-a374-bcfb68aa11f7
101               resume=UUID=3f5ad593-4546-4a94-a374-bcfb68aa11f7
102
103
104       rd.skipfsck
105           skip fsck for rootfs and /usr. If you’re mounting /usr read-only
106           and the init system performs fsck before remount, you might want to
107           use this option to avoid duplication.
108
109   iso-scan/filename
110       Using iso-scan/filename with a Fedora/Red Hat/CentOS Live iso should
111       just work by copying the original kernel cmdline parameters.
112
113       Example.
114
115           menuentry 'Live Fedora 20' --class fedora --class gnu-linux --class gnu --class os {
116               set isolabel=Fedora-Live-LXDE-x86_64-20-1
117               set isofile="/boot/iso/Fedora-Live-LXDE-x86_64-20-1.iso"
118               loopback loop $isofile
119               linux (loop)/isolinux/vmlinuz0 boot=isolinux iso-scan/filename=$isofile root=live:LABEL=$isolabel ro rd.live.image quiet rhgb
120               initrd (loop)/isolinux/initrd0.img
121           }
122
123
124   Misc
125       rd.emergency=[reboot|poweroff|halt]
126           specify, what action to execute in case of a critical failure.
127           rd.shell=0 also be specified.
128
129       rd.driver.blacklist=<drivername>[,<drivername>,...]
130           do not load kernel module <drivername>. This parameter can be
131           specified multiple times.
132
133       rd.driver.pre=<drivername>[,<drivername>,...]
134           force loading kernel module <drivername>. This parameter can be
135           specified multiple times.
136
137       rd.driver.post=<drivername>[,<drivername>,...]
138           force loading kernel module <drivername> after all automatic
139           loading modules have been loaded. This parameter can be specified
140           multiple times.
141
142       rd.retry=<seconds>
143           specify how long dracut should retry the initqueue to configure
144           devices. The default is 30 seconds. After 2/3 of the time, degraded
145           raids are force started. If you have hardware, which takes a very
146           long time to announce its drives, you might want to extend this
147           value.
148
149       rd.timeout=<seconds>
150           specify how long dracut should wait for devices to appear. The
151           default is 0, which means forever. Note that this timeout should be
152           longer than rd.retry to allow for proper configuration.
153
154       rd.noverifyssl
155           accept self-signed certificates for ssl downloads.
156
157       rd.ctty=<terminal device>
158           specify the controlling terminal for the console. This is useful,
159           if you have multiple "console=" arguments.
160
161   Debug
162       If you are dropped to an emergency shell, the file
163       /run/initramfs/rdsosreport.txt is created, which can be saved to a (to
164       be mounted by hand) partition (usually /boot) or a USB stick.
165       Additional debugging info can be produced by adding rd.debug to the
166       kernel command line. /run/initramfs/rdsosreport.txt contains all logs
167       and the output of some tools. It should be attached to any report about
168       dracut problems.
169
170       rd.info
171           print informational output though "quiet" is set
172
173       rd.shell
174           allow dropping to a shell, if root mounting fails
175
176       rd.debug
177           set -x for the dracut shell. If systemd is active in the initramfs,
178           all output is logged to the systemd journal, which you can inspect
179           with "journalctl -ab". If systemd is not active, the logs are
180           written to dmesg and /run/initramfs/init.log. If "quiet" is set, it
181           also logs to the console.
182
183       rd.memdebug=[0-4]
184           Print memory usage info at various points, set the verbose level
185           from 0 to 4.
186
187               Higher level means more debugging output:
188
189                   0 - no output
190                   1 - partial /proc/meminfo
191                   2 - /proc/meminfo
192                   3 - /proc/meminfo + /proc/slabinfo
193                   4 - /proc/meminfo + /proc/slabinfo + tracekomem
194                       NOTE: tracekomem is a shell script utilizing kernel trace to track
195                             the rough total memory consumption of kernel modules during
196                             loading. It may override other trace configurations.
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       rd.vconsole.keymap=<keymap base file name>
212           keyboard translation table loaded by loadkeys; taken from keymaps
213           directory; will be written as KEYMAP to /etc/vconsole.conf in the
214           initramfs.
215
216           Example.
217
218               rd.vconsole.keymap=de-latin1-nodeadkeys
219
220
221       rd.vconsole.keymap.ext=<list of keymap base file names>
222           list of extra keymaps to bo loaded (sep. by space); will be written
223           as EXT_KEYMAP to /etc/vconsole.conf in the initramfs
224
225       rd.vconsole.unicode
226           boolean, indicating UTF-8 mode; will be written as UNICODE to
227           /etc/vconsole.conf in the initramfs
228
229       rd.vconsole.font=<font base file name>
230           console font; taken from consolefonts directory; will be written as
231           FONT to /etc/vconsole.conf in the initramfs.
232
233           Example.
234
235               rd.vconsole.font=LatArCyrHeb-16
236
237
238       rd.vconsole.font.map=<console map base file name>
239           see description of -m parameter in setfont manual; taken from
240           consoletrans directory; will be written as FONT_MAP to
241           /etc/vconsole.conf in the initramfs
242
243       rd.vconsole.font.unimap=<unicode table base file name>
244           see description of -u parameter in setfont manual; taken from
245           unimaps directory; will be written as FONT_UNIMAP to
246           /etc/vconsole.conf in the initramfs
247
248       rd.locale.LANG=<locale>
249           taken from the environment; if no UNICODE is defined we set its
250           value in basis of LANG value (whether it ends with ".utf8" (or
251           similar) or not); will be written as LANG to /etc/locale.conf in
252           the initramfs.
253
254           Example.
255
256               rd.locale.LANG=pl_PL.utf8
257
258
259       rd.locale.LC_ALL=<locale>
260           taken from the environment; will be written as LC_ALL to
261           /etc/locale.conf in the initramfs
262
263   LVM
264       rd.lvm=0
265           disable LVM detection
266
267       rd.lvm.vg=<volume group name>
268           only activate the volume groups with the given name. rd.lvm.vg can
269           be specified multiple times on the kernel command line.
270
271       rd.lvm.lv=<logical volume name>
272           only activate the logical volumes with the given name. rd.lvm.lv
273           can be specified multiple times on the kernel command line.
274
275       rd.lvm.conf=0
276           remove any /etc/lvm/lvm.conf, which may exist in the initramfs
277
278   crypto LUKS
279       rd.luks=0
280           disable crypto LUKS detection
281
282       rd.luks.uuid=<luks uuid>
283           only activate the LUKS partitions with the given UUID. Any "luks-"
284           of the LUKS UUID is removed before comparing to <luks uuid>. The
285           comparisons also matches, if <luks uuid> is only the beginning of
286           the LUKS UUID, so you don’t have to specify the full UUID. This
287           parameter can be specified multiple times.
288
289       rd.luks.allow-discards=<luks uuid>
290           Allow using of discards (TRIM) requests for LUKS partitions with
291           the given UUID. Any "luks-" of the LUKS UUID is removed before
292           comparing to <luks uuid>. The comparisons also matches, if <luks
293           uuid> is only the beginning of the LUKS UUID, so you don’t have to
294           specify the full UUID. This parameter can be specified multiple
295           times.
296
297       rd.luks.allow-discards
298           Allow using of discards (TRIM) requests on all LUKS partitions.
299
300       rd.luks.crypttab=0
301           do not check, if LUKS partition is in /etc/crypttab
302
303       rd.luks.timeout=<seconds>
304           specify how long dracut should wait when waiting for the user to
305           enter the password. This avoid blocking the boot if no password is
306           entered. It does not apply to luks key. The default is 0, which
307           means forever.
308
309   crypto LUKS - key on removable device support
310       rd.luks.key=<keypath>:<keydev>:<luksdev>
311           keypath is a path to key file to look for. It’s REQUIRED. When
312           keypath ends with .gpg it’s considered to be key encrypted
313           symmetrically with GPG. You will be prompted for password on boot.
314           GPG support comes with crypt-gpg module which needs to be added
315           explicitly.
316
317           keydev is a device on which key file resides. It might be kernel
318           name of devices (should start with "/dev/"), UUID (prefixed with
319           "UUID=") or label (prefix with "LABEL="). You don’t have to specify
320           full UUID. Just its beginning will suffice, even if its ambiguous.
321           All matching devices will be probed. This parameter is recommended,
322           but not required. If not present, all block devices will be probed,
323           which may significantly increase boot time.
324
325           If luksdev is given, the specified key will only be applied for
326           that LUKS device. Possible values are the same as for keydev.
327           Unless you have several LUKS devices, you don’t have to specify
328           this parameter. The simplest usage is:
329
330           Example.
331
332               rd.luks.key=/foo/bar.key
333
334
335           As you see, you can skip colons in such a case.
336
337               Note
338               dracut pipes key to cryptsetup with -d - argument, therefore
339               you need to pipe to crypsetup luksFormat with -d -, too!
340
341               Here follows example for key encrypted with GPG:
342
343                   gpg --quiet --decrypt rootkey.gpg | \
344                   cryptsetup -d - -v --cipher serpent-cbc-essiv:sha256 \
345                   --key-size 256 luksFormat /dev/sda3
346
347               If you use plain keys, just add path to -d option:
348
349                   cryptsetup -d rootkey.key -v --cipher serpent-cbc-essiv:sha256 \
350                    --key-size 256 luksFormat /dev/sda3
351
352   MD RAID
353       rd.md=0
354           disable MD RAID detection
355
356       rd.md.imsm=0
357           disable MD RAID for imsm/isw raids, use DM RAID instead
358
359       rd.md.ddf=0
360           disable MD RAID for SNIA ddf raids, use DM RAID instead
361
362       rd.md.conf=0
363           ignore mdadm.conf included in initramfs
364
365       rd.md.waitclean=1
366           wait for any resync, recovery, or reshape activity to finish before
367           continuing
368
369       rd.md.uuid=<md raid uuid>
370           only activate the raid sets with the given UUID. This parameter can
371           be specified multiple times.
372
373   DM RAID
374       rd.dm=0
375           disable DM RAID detection
376
377       rd.dm.uuid=<dm raid uuid>
378           only activate the raid sets with the given UUID. This parameter can
379           be specified multiple times.
380
381   MULTIPATH
382       rd.multipath=0
383           disable multipath detection
384
385   FIPS
386       rd.fips
387           enable FIPS
388
389       boot=<boot device>
390           specify the device, where /boot is located.
391
392           Example.
393
394               boot=/dev/sda1
395               boot=/dev/disk/by-path/pci-0000:00:1f.1-scsi-0:0:1:0-part1
396               boot=UUID=<uuid>
397               boot=LABEL=<label>
398
399
400       rd.fips.skipkernel
401           skip checksum check of the kernel image. Useful, if the kernel
402           image is not in a separate boot partition.
403
404   Network
405           Important
406           It is recommended to either bind an interface to a MAC with the
407           ifname argument, or to use the systemd-udevd predictable network
408           interface names.
409
410           Predictable network interface device names based on:
411
412           ·   firmware/bios-provided index numbers for on-board devices
413
414           ·   firmware-provided pci-express hotplug slot index number
415
416           ·   physical/geographical location of the hardware
417
418           ·   the interface’s MAC address
419
420           See:
421           http://www.freedesktop.org/wiki/Software/systemd/PredictableNetworkInterfaceNames
422
423           Two character prefixes based on the type of interface:
424
425           en
426               ethernet
427
428           wl
429               wlan
430
431           ww
432               wwan
433
434           Type of names:
435
436           o<index>
437               on-board device index number
438
439           s<slot>[f<function>][d<dev_id>]
440               hotplug slot index number
441
442           x<MAC>
443               MAC address
444
445           [P<domain>]p<bus>s<slot>[f<function>][d<dev_id>]
446               PCI geographical location
447
448           [P<domain>]p<bus>s<slot>[f<function>][u<port>][..][c<config>][i<interface>]
449               USB port number chain
450
451           All multi-function PCI devices will carry the [f<function>] number
452           in the device name, including the function 0 device.
453
454           When using PCI geography, The PCI domain is only prepended when it
455           is not 0.
456
457           For USB devices the full chain of port numbers of hubs is composed.
458           If the name gets longer than the maximum number of 15 characters,
459           the name is not exported. The usual USB configuration == 1 and
460           interface == 0 values are suppressed.
461
462           PCI ethernet card with firmware index "1"
463
464               ·   eno1
465
466           PCI ethernet card in hotplug slot with firmware index number
467
468               ·   ens1
469
470           PCI ethernet multi-function card with 2 ports
471
472               ·   enp2s0f0
473
474               ·   enp2s0f1
475
476           PCI wlan card
477
478               ·   wlp3s0
479
480           USB built-in 3G modem
481
482               ·   wwp0s29u1u4i6
483
484           USB Android phone
485
486               ·   enp0s29u1u2
487
488       ip={dhcp|on|any|dhcp6|auto6|either6}
489
490           dhcp|on|any
491               get ip from dhcp server from all interfaces. If root=dhcp, loop
492               sequentially through all interfaces (eth0, eth1, ...) and use
493               the first with a valid DHCP root-path.
494
495           auto6
496               IPv6 autoconfiguration
497
498           dhcp6
499               IPv6 DHCP
500
501           either6
502               if auto6 fails, then dhcp6
503
504       ip=<interface>:{dhcp|on|any|dhcp6|auto6}[:[<mtu>][:<macaddr>]]
505           This parameter can be specified multiple times.
506
507           dhcp|on|any|dhcp6
508               get ip from dhcp server on a specific interface
509
510           auto6
511               do IPv6 autoconfiguration
512
513           <macaddr>
514               optionally set <macaddr> on the <interface>. This cannot be
515               used in conjunction with the ifname argument for the same
516               <interface>.
517
518       ip=<client-IP>:[<peer>]:<gateway-IP>:<netmask>:<client_hostname>:<interface>:{none|off|dhcp|on|any|dhcp6|auto6|ibft}[:[<mtu>][:<macaddr>]]
519           explicit network configuration. If you want do define a IPv6
520           address, put it in brackets (e.g. [2001:DB8::1]). This parameter
521           can be specified multiple times.  <peer> is optional and is the
522           address of the remote endpoint for pointopoint interfaces and it
523           may be followed by a slash and a decimal number, encoding the
524           network prefix length.
525
526           <macaddr>
527               optionally set <macaddr> on the <interface>. This cannot be
528               used in conjunction with the ifname argument for the same
529               <interface>.
530
531       ip=<client-IP>:[<peer>]:<gateway-IP>:<netmask>:<client_hostname>:<interface>:{none|off|dhcp|on|any|dhcp6|auto6|ibft}[:[<dns1>][:<dns2>]]
532           explicit network configuration. If you want do define a IPv6
533           address, put it in brackets (e.g. [2001:DB8::1]). This parameter
534           can be specified multiple times.  <peer> is optional and is the
535           address of the remote endpoint for pointopoint interfaces and it
536           may be followed by a slash and a decimal number, encoding the
537           network prefix length.
538
539       ifname=<interface>:<MAC>
540           Assign network device name <interface> (ie "bootnet") to the NIC
541           with MAC <MAC>.
542
543               Warning
544               Do not use the default kernel naming scheme for the interface
545               name, as it can conflict with the kernel names. So, don’t use
546               "eth[0-9]+" for the interface name. Better name it "bootnet" or
547               "bluesocket".
548
549       rd.route=<net>/<netmask>:<gateway>[:<interface>]
550           Add a static route with route options, which are separated by a
551           colon. IPv6 addresses have to be put in brackets.
552
553           Example.
554
555                   rd.route=192.168.200.0/24:192.168.100.222:ens10
556                   rd.route=192.168.200.0/24:192.168.100.222
557                   rd.route=192.168.200.0/24::ens10
558                   rd.route=[2001:DB8:3::/8]:[2001:DB8:2::1]:ens10
559
560
561       bootdev=<interface>
562           specify network interface to use routing and netroot information
563           from. Required if multiple ip= lines are used.
564
565       BOOTIF=<MAC>
566           specify network interface to use routing and netroot information
567           from.
568
569       rd.bootif=0
570           Disable BOOTIF parsing, which is provided by PXE
571
572       nameserver=<IP> [nameserver=<IP> ...]
573           specify nameserver(s) to use
574
575       rd.peerdns=0
576           Disable DNS setting of DHCP parameters.
577
578       biosdevname=0
579           boolean, turn off biosdevname network interface renaming
580
581       rd.neednet=1
582           boolean, bring up network even without netroot set
583
584       vlan=<vlanname>:<phydevice>
585           Setup vlan device named <vlanname> on <phydeivce>. We support the
586           four styles of vlan names: VLAN_PLUS_VID (vlan0005),
587           VLAN_PLUS_VID_NO_PAD (vlan5), DEV_PLUS_VID (eth0.0005),
588           DEV_PLUS_VID_NO_PAD (eth0.5)
589
590       bond=<bondname>[:<bondslaves>:[:<options>[:<mtu>]]]
591           Setup bonding device <bondname> on top of <bondslaves>.
592           <bondslaves> is a comma-separated list of physical (ethernet)
593           interfaces. <options> is a comma-separated list on bonding options
594           (modinfo bonding for details) in format compatible with
595           initscripts. If <options> includes multi-valued arp_ip_target
596           option, then its values should be separated by semicolon. if the
597           mtu is specified, it will be set on the bond master. Bond without
598           parameters assumes bond=bond0:eth0,eth1:mode=balance-rr
599
600       team=<teammaster>:<teamslaves>
601           Setup team device <teammaster> on top of <teamslaves>. <teamslaves>
602           is a comma-separated list of physical (ethernet) interfaces.
603
604       bridge=<bridgename>:<ethnames>
605           Setup bridge <bridgename> with <ethnames>. <ethnames> is a
606           comma-separated list of physical (ethernet) interfaces. Bridge
607           without parameters assumes bridge=br0:eth0
608
609   NFS
610       root=[<server-ip>:]<root-dir>[:<nfs-options>]
611           mount nfs share from <server-ip>:/<root-dir>, if no server-ip is
612           given, use dhcp next_server. If server-ip is an IPv6 address it has
613           to be put in brackets, e.g. [2001:DB8::1]. NFS options can be
614           appended with the prefix ":" or "," and are separated by ",".
615
616       root=nfs:[<server-ip>:]<root-dir>[:<nfs-options>],
617       root=nfs4:[<server-ip>:]<root-dir>[:<nfs-options>], root={dhcp|dhcp6}
618           root=dhcp alone directs initrd to look at the DHCP root-path where
619           NFS options can be specified.
620
621           Example.
622
623                   root-path=<server-ip>:<root-dir>[,<nfs-options>]
624                   root-path=nfs:<server-ip>:<root-dir>[,<nfs-options>]
625                   root-path=nfs4:<server-ip>:<root-dir>[,<nfs-options>]
626
627
628       root=/dev/nfs nfsroot=[<server-ip>:]<root-dir>[:<nfs-options>]
629           Deprecated!  kernel Documentation_/filesystems/nfsroot.txt_ defines
630           this method. This is supported by dracut, but not recommended.
631
632       rd.nfs.domain=<NFSv4 domain name>
633           Set the NFSv4 domain name. Will override the settings in
634           /etc/idmap.conf.
635
636       rd.net.dhcp.retry=<cnt>
637           If this option is set, dracut will try to connect via dhcp <cnt>
638           times before failing. Default is 1.
639
640       rd.net.timeout.dhcp=<arg>
641           If this option is set, dhclient is called with "-timeout <arg>".
642
643       rd.net.timeout.iflink=<seconds>
644           Wait <seconds> until link shows up. Default is 60 seconds.
645
646       rd.net.timeout.ifup=<seconds>
647           Wait <seconds> until link has state "UP". Default is 20 seconds.
648
649       rd.net.timeout.route=<seconds>
650           Wait <seconds> until route shows up. Default is 20 seconds.
651
652       rd.net.timeout.ipv6dad=<seconds>
653           Wait <seconds> until IPv6 DAD is finished. Default is 50 seconds.
654
655       rd.net.timeout.ipv6auto=<seconds>
656           Wait <seconds> until IPv6 automatic addresses are assigned. Default
657           is 40 seconds.
658
659       rd.net.timeout.carrier=<seconds>
660           Wait <seconds> until carrier is recognized. Default is 5 seconds.
661
662   CIFS
663       root=cifs://[<username>[:<password>]@]<server-ip>:<root-dir>
664           mount cifs share from <server-ip>:/<root-dir>, if no server-ip is
665           given, use dhcp next_server. if server-ip is an IPv6 address it has
666           to be put in brackets, e.g. [2001:DB8::1]. If a username or
667           password are not specified as part of the root, then they must be
668           passed on the command line through cifsuser/cifspass.
669
670               Warning
671               Passwords specified on the kernel command line are visible for
672               all users via the file /proc/cmdline and via dmesg or can be
673               sniffed on the network, when using DHCP with DHCP root-path.
674
675       cifsuser=<username>
676           Set the cifs username, if not specified as part of the root.
677
678       cifspass=<password>
679           Set the cifs password, if not specified as part of the root.
680
681               Warning
682               Passwords specified on the kernel command line are visible for
683               all users via the file /proc/cmdline and via dmesg or can be
684               sniffed on the network, when using DHCP with DHCP root-path.
685
686   iSCSI
687       root=iscsi:[<username>:<password>[:<reverse>:<password>]@][<servername>]:[<protocol>]:[<port>][:[<iscsi_iface_name>]:[<netdev_name>]]:[<LUN>]:<targetname>
688           protocol defaults to "6", LUN defaults to "0". If the "servername"
689           field is provided by BOOTP or DHCP, then that field is used in
690           conjunction with other associated fields to contact the boot server
691           in the Boot stage. However, if the "servername" field is not
692           provided, then the "targetname" field is then used in the Discovery
693           Service stage in conjunction with other associated fields. See
694           rfc4173[1].
695
696               Warning
697               Passwords specified on the kernel command line are visible for
698               all users via the file /proc/cmdline and via dmesg or can be
699               sniffed on the network, when using DHCP with DHCP root-path.
700
701           Example.
702
703               root=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
704
705
706           If servername is an IPv6 address, it has to be put in brackets:
707
708           Example.
709
710               root=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0
711
712
713       root=???
714       netroot=iscsi:[<username>:<password>[:<reverse>:<password>]@][<servername>]:[<protocol>]:[<port>][:[<iscsi_iface_name>]:[<netdev_name>]]:[<LUN>]:<targetname>
715       ...
716           multiple netroot options allow setting up multiple iscsi disks:
717
718           Example.
719
720               root=UUID=12424547
721               netroot=iscsi:192.168.50.1::::iqn.2009-06.dracut:target0
722               netroot=iscsi:192.168.50.1::::iqn.2009-06.dracut:target1
723
724
725           If servername is an IPv6 address, it has to be put in brackets:
726
727           Example.
728
729               netroot=iscsi:[2001:DB8::1]::::iqn.2009-06.dracut:target0
730
731
732               Warning
733               Passwords specified on the kernel command line are visible for
734               all users via the file /proc/cmdline and via dmesg or can be
735               sniffed on the network, when using DHCP with DHCP root-path.
736               You may want to use rd.iscsi.firmware.
737
738       root=??? rd.iscsi.initiator=<initiator> rd.iscsi.target.name=<target
739       name> rd.iscsi.target.ip=<target ip> rd.iscsi.target.port=<target port>
740       rd.iscsi.target.group=<target group> rd.iscsi.username=<username>
741       rd.iscsi.password=<password> rd.iscsi.in.username=<in username>
742       rd.iscsi.in.password=<in password>
743           manually specify all iscsistart parameter (see iscsistart --help)
744
745               Warning
746               Passwords specified on the kernel command line are visible for
747               all users via the file /proc/cmdline and via dmesg or can be
748               sniffed on the network, when using DHCP with DHCP root-path.
749               You may want to use rd.iscsi.firmware.
750
751       root=??? netroot=iscsi rd.iscsi.firmware=1
752           will read the iscsi parameter from the BIOS firmware
753
754       rd.iscsi.login_retry_max=<num>
755           maximum number of login retries
756
757       rd.iscsi.param=<param>
758           <param> will be passed as "--param <param>" to iscsistart. This
759           parameter can be specified multiple times.
760
761           Example.
762
763               "netroot=iscsi rd.iscsi.firmware=1 rd.iscsi.param=node.session.timeo.replacement_timeout=30"
764
765
766           will result in
767
768               iscsistart -b --param node.session.timeo.replacement_timeout=30
769
770       rd.iscsi.ibft rd.iscsi.ibft=1: Turn on iBFT autoconfiguration for the
771       interfaces
772
773       rd.iscsi.waitnet=0: Turn off waiting for all interfaces to be up before
774       trying to login to the iSCSI targets.
775
776       rd.iscsi.testroute=0: Turn off checking, if the route to the iSCSI
777       target IP is possible before trying to login.
778
779   FCoE
780       fcoe=<edd|interface|MAC>:{dcb|nodcb}:{fabric|vn2vn}
781           Try to connect to a FCoE SAN through the NIC specified by
782           <interface> or <MAC> or EDD settings. The second argument specifies
783           if DCB should be used. The optional third argument specifies
784           whether fabric or VN2VN mode should be used. This parameter can be
785           specified multiple times.
786
787               Note
788               letters in the MAC-address must be lowercase!
789
790   NBD
791       root=???
792       netroot=nbd:<server>:<port/exportname>[:<fstype>[:<mountopts>[:<nbdopts>]]]
793           mount nbd share from <server>.
794
795           NOTE: If "exportname" instead of "port" is given the standard port
796           is used. Newer versions of nbd are only supported with
797           "exportname".
798
799       root=dhcp with dhcp
800       root-path=nbd:<server>:<port/exportname>[:<fstype>[:<mountopts>[:<nbdopts>]]]
801           root=dhcp alone directs initrd to look at the DHCP root-path where
802           NBD options can be specified. This syntax is only usable in cases
803           where you are directly mounting the volume as the rootfs.
804
805           NOTE: If "exportname" instead of "port" is given the standard port
806           is used. Newer versions of nbd are only supported with
807           "exportname".
808
809   DASD
810       rd.dasd=....
811           same syntax as the kernel module parameter (s390 only)
812
813   ZFCP
814       rd.zfcp=<zfcp adaptor device bus ID>,<WWPN>,<FCPLUN>
815           rd.zfcp can be specified multiple times on the kernel command line.
816
817       rd.zfcp=<zfcp adaptor device bus ID>
818           If NPIV is enabled and the allow_lun_scan parameter to the zfcp
819           module is set to Y then the zfcp adaptor will be initiating a scan
820           internally and the <WWPN> and <FCPLUN> parameters can be omitted.
821
822           Example.
823
824               rd.zfcp=0.0.4000,0x5005076300C213e9,0x5022000000000000
825               rd.zfcp=0.0.4000
826
827
828       rd.zfcp.conf=0
829           ignore zfcp.conf included in the initramfs
830
831   ZNET
832       rd.znet=<nettype>,<subchannels>,<options>
833           The whole parameter is appended to /etc/ccw.conf, which is used on
834           RHEL/Fedora with ccw_init, which is called from udev for certain
835           devices on z-series. rd.znet can be specified multiple times on the
836           kernel command line.
837
838           Example.
839
840               rd.znet=qeth,0.0.0600,0.0.0601,0.0.0602,layer2=1,portname=foo
841               rd.znet=ctc,0.0.0600,0.0.0601,protocol=bar
842
843
844   Booting live images
845       Dracut offers multiple options for live booted images:
846
847       SquashFS with read-only filesystem image
848           The system will boot with a read-only filesystem from the SquashFS
849           and apply a writable Device-mapper snapshot or an OverlayFS overlay
850           mount for the read-only base filesystem. This method ensures a
851           relatively fast boot and lower RAM usage. Users must be careful to
852           avoid writing too many blocks to a snapshot volume. Once the blocks
853           of the snapshot overlay are exhausted, the root filesystem becomes
854           read-only and may cause application failures. The snapshot overlay
855           file is marked Overflow, and a difficult recovery is required to
856           repair and enlarge the overlay offline. Non-persistent overlays are
857           sparse files in RAM that only consume content space as required
858           blocks are allocated. They default to an apparent size of 32 GiB in
859           RAM. The size can be adjusted with the rd.live.overlay.size= kernel
860           command line option.
861
862           The filesystem structure is traditionally expected to be:
863
864               squashfs.img          |  SquashFS from LiveCD .iso
865                  !(mount)
866                  /LiveOS
867                      |- rootfs.img  |  Filesystem image to mount read-only
868                           !(mount)
869                           /bin      |  Live filesystem
870                           /boot     |
871                           /dev      |
872                           ...       |
873
874           For OverlayFS mount overlays, the filesystem structure may also be
875           a direct compression of the root filesystem:
876
877               squashfs.img          |  SquashFS from LiveCD .iso
878                  !(mount)
879                  /bin               |  Live filesystem
880                  /boot              |
881                  /dev               |
882                  ...                |
883
884           Dracut uses one of the overlay methods of live booting by default.
885           No additional command line options are required other than
886           root=live:<URL> to specify the location of your squashed
887           filesystem.
888
889           ·   The compressed SquashFS image can be copied during boot to RAM
890               at /run/initramfs/squashed.img by using the rd.live.ram=1
891               option.
892
893           ·   A device with a persistent overlay can be booted read-only by
894               using the rd.live.overlay.readonly option on the kernel command
895               line. This will either cause a temporary, writable overlay to
896               be stacked over a read-only snapshot of the root filesystem or
897               the OverlayFS mount will use an additional lower layer with the
898               root filesystem.
899
900       Uncompressed live filesystem image
901           When the live system was installed with the --skipcompress option
902           of the livecd-iso-to-disk installation script for Live USB devices,
903           the root filesystem image, rootfs.img, is expanded on installation
904           and no SquashFS is involved during boot.
905
906           ·   If rd.live.ram=1 is used in this situation, the full,
907               uncompressed root filesystem is copied during boot to
908               /run/initramfs/rootfs.img in the /run tmpfs.
909
910           ·   If rd.live.overlay=none is provided as a kernel command line
911               option, a writable, linear Device-mapper target is created on
912               boot with no overlay.
913
914       Writable filesystem image
915           The system will retrieve a compressed filesystem image, extract it
916           to /run/initramfs/fsimg/rootfs.img, connect it to a loop device,
917           create a writable, linear Device-mapper target at
918           /dev/mapper/live-rw, and mount that as a writable volume at /. More
919           RAM is required during boot but the live filesystem is easier to
920           manage if it becomes full. Users can make a filesystem image of any
921           size and that size will be maintained when the system boots. There
922           is no persistence of root filesystem changes between boots with
923           this option.
924
925           The filesystem structure is expected to be:
926
927               rootfs.tgz            |  Compressed tarball containing filesystem image
928                  !(unpack)
929                  /rootfs.img        |  Filesystem image at /run/initramfs/fsimg/
930                     !(mount)
931                     /bin            |  Live filesystem
932                     /boot           |
933                     /dev            |
934                     ...             |
935
936           To use this boot option, ensure that rd.writable.fsimg=1 is in your
937           kernel command line and add the root=live:<URL> to specify the
938           location of your compressed filesystem image tarball or SquashFS
939           image.
940
941       rd.writable.fsimg=1
942           Enables writable filesystem support. The system will boot with a
943           fully writable (but non-persistent) filesystem without snapshots
944           (see notes above about available live boot options). You can use
945           the rootflags option to set mount options for the live filesystem
946           as well (see documentation about rootflags in the Standard section
947           above). This implies that the whole image is copied to RAM before
948           the boot continues.
949
950               Note
951               There must be enough free RAM available to hold the complete
952               image.
953           This method is very suitable for diskless boots.
954
955       root=live:<url>
956           Boots a live image retrieved from <url>. Requires the dracut
957           livenet module. Valid handlers: http, https, ftp, torrent, tftp.
958
959           Examples.
960
961               root=live:http://example.com/liveboot.img
962               root=live:ftp://ftp.example.com/liveboot.img
963               root=live:torrent://example.com/liveboot.img.torrent
964
965
966       rd.live.debug=1
967           Enables debug output from the live boot process.
968
969       rd.live.dir=<path>
970           Specifies the directory within the boot device where the
971           squashfs.img or rootfs.img can be found. By default, this is
972           /LiveOS.
973
974       rd.live.squashimg=<filename of SquashFS image>
975           Specifies the filename for a SquashFS image of the root filesystem.
976           By default, this is squashfs.img.
977
978       rd.live.ram=1
979           Copy the complete image to RAM and use this for booting. This is
980           useful when the image resides on, e.g., a DVD which needs to be
981           ejected later on.
982
983       rd.live.overlay={<devspec>[:{<pathspec>|auto}]|none}
984           Manage the usage of a permanent overlay.
985
986           ·   <devspec> specifies the path to a device with a mountable
987               filesystem.
988
989           ·   <pathspec> is the path to a file within that filesystem, which
990               shall be used to persist the changes made to the device
991               specified by the root=live:<url> option.
992
993               The default pathspec, when auto or no :<pathspec> is given, is
994               /<<b>rd.live.dir</b>>/overlay-<label>-<uuid>, where <label> is
995               the device LABEL, and <uuid> is the device UUID. * none (the
996               word itself) specifies that no overlay will be used, such as
997               when an uncompressed, writable live root filesystem is
998               available.
999
1000               If a persistent overlay is detected at the standard LiveOS
1001               path, the overlay & overlay type detected, whether
1002               Device-mapper or OverlayFS, will be used.
1003
1004           Examples.
1005
1006               rd.live.overlay=/dev/sdb1:persistent-overlay.img
1007               rd.live.overlay=UUID=99440c1f-8daa-41bf-b965-b7240a8996f4
1008
1009
1010       rd.live.overlay.size=<size_MiB>
1011           Specifies a non-persistent Device-mapper overlay size in MiB. The
1012           default is 32768.
1013
1014       rd.live.overlay.readonly=1
1015           This is used to boot with a normally read-write persistent overlay
1016           in a read-only mode. With this option, either an additional,
1017           non-persistent, writable snapshot overlay will be stacked over a
1018           read-only snapshot, /dev/mapper/live-ro, of the base filesystem
1019           with the persistent overlay, or a read-only loop device, in the
1020           case of a writable rootfs.img, or an OverlayFS mount will use the
1021           persistent overlay directory linked at /run/overlayfs-r as an
1022           additional lower layer along with the base root filesystem and
1023           apply a transient, writable upper directory overlay, in order to
1024           complete the booted root filesystem.
1025
1026       rd.live.overlay.reset=1
1027           Specifies that a persistent overlay should be reset on boot. All
1028           previous root filesystem changes are vacated by this action.
1029
1030       rd.live.overlay.thin=1
1031           Enables the usage of thin snapshots instead of classic dm
1032           snapshots. The advantage of thin snapshots is that they support
1033           discards, and will free blocks that are not claimed by the
1034           filesystem. In this use case, this means that memory is given back
1035           to the kernel when the filesystem does not claim it anymore.
1036
1037       rd.live.overlay.overlayfs=1
1038           Enables the use of the OverlayFS kernel module, if available, to
1039           provide a copy-on-write union directory for the root filesystem.
1040           OverlayFS overlays are directories of the files that have changed
1041           on the read-only base (lower) filesystem. The root filesystem is
1042           provided through a special overlay type mount that merges the lower
1043           and upper directories. If an OverlayFS upper directory is not
1044           present on the boot device, a tmpfs directory will be created at
1045           /run/overlayfs to provide temporary storage. Persistent storage can
1046           be provided on vfat or msdos formatted devices by supplying the
1047           OverlayFS upper directory within an embedded filesystem that
1048           supports the creation of trusted.* extended attributes and provides
1049           a valid d_type in readdir responses, such as with ext4 and xfs. On
1050           non-vfat-formatted devices, a persistent OverlayFS overlay can
1051           extend the available root filesystem storage up to the capacity of
1052           the LiveOS disk device.
1053
1054           If a persistent overlay is detected at the standard LiveOS path,
1055           the overlay & overlay type detected, whether OverlayFS or
1056           Device-mapper, will be used.
1057
1058           The rd.live.overlay.readonly option, which allows a persistent
1059           overlayfs to be mounted read-only through a higher level transient
1060           overlay directory, has been implemented through the multiple lower
1061           layers feature of OverlayFS.
1062
1063   ZIPL
1064       rd.zipl=<path to blockdevice>
1065           Update the dracut commandline with the values found in the
1066           dracut-cmdline.conf file on the given device. The values are merged
1067           into the existing commandline values and the udev events are
1068           regenerated.
1069
1070           Example.
1071
1072               rd.zipl=UUID=0fb28157-99e3-4395-adef-da3f7d44835a
1073
1074
1075   CIO_IGNORE
1076       rd.cio_accept=<device-ids>
1077           Remove the devices listed in <device-ids> from the default
1078           cio_ignore kernel command-line settings. <device-ids> is a list of
1079           comma-separated CCW device ids. The default for this value is taken
1080           from the /boot/zipl/active_devices.txt file.
1081
1082           Example.
1083
1084               rd.cio_accept=0.0.0180,0.0.0800,0.0.0801,0.0.0802
1085
1086
1087   Plymouth Boot Splash
1088       plymouth.enable=0
1089           disable the plymouth bootsplash completely.
1090
1091       rd.plymouth=0
1092           disable the plymouth bootsplash only for the initramfs.
1093
1094   Kernel keys
1095       masterkey=<kernel master key path name>
1096           Set the path name of the kernel master key.
1097
1098           Example.
1099
1100               masterkey=/etc/keys/kmk-trusted.blob
1101
1102
1103       masterkeytype=<kernel master key type>
1104           Set the type of the kernel master key.
1105
1106           Example.
1107
1108               masterkeytype=trusted
1109
1110
1111       evmkey=<EVM key path name>
1112           Set the path name of the EVM key.
1113
1114           Example.
1115
1116               evmkey=/etc/keys/evm-trusted.blob
1117
1118
1119       ecryptfskey=<eCryptfs key path name>
1120           Set the path name of the eCryptfs key.
1121
1122           Example.
1123
1124               ecryptfskey=/etc/keys/ecryptfs-trusted.blob
1125
1126
1127   Deprecated, renamed Options
1128       Here is a list of options, which were used in dracut prior to version
1129       008, and their new replacement.
1130
1131       rdbreak
1132           rd.break
1133
1134       rd.ccw
1135           rd.znet
1136
1137       rd_CCW
1138           rd.znet
1139
1140       rd_DASD_MOD
1141           rd.dasd
1142
1143       rd_DASD
1144           rd.dasd
1145
1146       rdinitdebug rdnetdebug
1147           rd.debug
1148
1149       rd_NO_DM
1150           rd.dm=0
1151
1152       rd_DM_UUID
1153           rd.dm.uuid
1154
1155       rdblacklist
1156           rd.driver.blacklist
1157
1158       rdinsmodpost
1159           rd.driver.post
1160
1161       rdloaddriver
1162           rd.driver.pre
1163
1164       rd_NO_FSTAB
1165           rd.fstab=0
1166
1167       rdinfo
1168           rd.info
1169
1170       check
1171           rd.live.check
1172
1173       rdlivedebug
1174           rd.live.debug
1175
1176       live_dir
1177           rd.live.dir
1178
1179       liveimg
1180           rd.live.image
1181
1182       overlay
1183           rd.live.overlay
1184
1185       readonly_overlay
1186           rd.live.overlay.readonly
1187
1188       reset_overlay
1189           rd.live.overlay.reset
1190
1191       live_ram
1192           rd.live.ram
1193
1194       rd_NO_CRYPTTAB
1195           rd.luks.crypttab=0
1196
1197       rd_LUKS_KEYDEV_UUID
1198           rd.luks.keydev.uuid
1199
1200       rd_LUKS_KEYPATH
1201           rd.luks.keypath
1202
1203       rd_NO_LUKS
1204           rd.luks=0
1205
1206       rd_LUKS_UUID
1207           rd.luks.uuid
1208
1209       rd_NO_LVMCONF
1210           rd.lvm.conf
1211
1212       rd_LVM_LV
1213           rd.lvm.lv
1214
1215       rd_NO_LVM
1216           rd.lvm=0
1217
1218       rd_LVM_SNAPSHOT
1219           rd.lvm.snapshot
1220
1221       rd_LVM_SNAPSIZE
1222           rd.lvm.snapsize
1223
1224       rd_LVM_VG
1225           rd.lvm.vg
1226
1227       rd_NO_MDADMCONF
1228           rd.md.conf=0
1229
1230       rd_NO_MDIMSM
1231           rd.md.imsm=0
1232
1233       rd_NO_MD
1234           rd.md=0
1235
1236       rd_MD_UUID
1237           rd.md.uuid
1238
1239       rd_NO_MULTIPATH: rd.multipath=0
1240
1241       rd_NFS_DOMAIN
1242           rd.nfs.domain
1243
1244       iscsi_initiator
1245           rd.iscsi.initiator
1246
1247       iscsi_target_name
1248           rd.iscsi.target.name
1249
1250       iscsi_target_ip
1251           rd.iscsi.target.ip
1252
1253       iscsi_target_port
1254           rd.iscsi.target.port
1255
1256       iscsi_target_group
1257           rd.iscsi.target.group
1258
1259       iscsi_username
1260           rd.iscsi.username
1261
1262       iscsi_password
1263           rd.iscsi.password
1264
1265       iscsi_in_username
1266           rd.iscsi.in.username
1267
1268       iscsi_in_password
1269           rd.iscsi.in.password
1270
1271       iscsi_firmware
1272           rd.iscsi.firmware=0
1273
1274       rd_NO_PLYMOUTH
1275           rd.plymouth=0
1276
1277       rd_retry
1278           rd.retry
1279
1280       rdshell
1281           rd.shell
1282
1283       rd_NO_SPLASH
1284           rd.splash
1285
1286       rdudevdebug
1287           rd.udev.debug
1288
1289       rdudevinfo
1290           rd.udev.info
1291
1292       rd_NO_ZFCPCONF
1293           rd.zfcp.conf=0
1294
1295       rd_ZFCP
1296           rd.zfcp
1297
1298       rd_ZNET
1299           rd.znet
1300
1301       KEYMAP
1302           vconsole.keymap
1303
1304       KEYTABLE
1305           vconsole.keymap
1306
1307       SYSFONT
1308           vconsole.font
1309
1310       CONTRANS
1311           vconsole.font.map
1312
1313       UNIMAP
1314           vconsole.font.unimap
1315
1316       UNICODE
1317           vconsole.unicode
1318
1319       EXT_KEYMAP
1320           vconsole.keymap.ext
1321
1322   Configuration in the Initramfs
1323       /etc/conf.d/
1324           Any files found in /etc/conf.d/ will be sourced in the initramfs to
1325           set initial values. Command line options will override these values
1326           set in the configuration files.
1327
1328       /etc/cmdline
1329           Can contain additional command line options. Deprecated, better use
1330           /etc/cmdline.d/*.conf.
1331
1332       /etc/cmdline.d/*.conf
1333           Can contain additional command line options.
1334

AUTHOR

1336       Harald Hoyer
1337

SEE ALSO

1339       dracut(8) dracut.conf(5)
1340

NOTES

1342        1. rfc4173
1343           http://tools.ietf.org/html/rfc4173#section-5
1344
1345
1346
1347dracut                            10/08/2018                 DRACUT.CMDLINE(7)
Impressum