dracut.8.asc

   1 DRACUT(8)
   2 =========
   3 :doctype: manpage
   4 :man source:   dracut
   5 :man manual:   dracut
   6
   7 NAME
   8 ----
   9 dracut - low-level tool for generating an initramfs/initrd image
  10
  11 SYNOPSIS
  12 --------
  13 *dracut* [__OPTION...__] [__<image>__ [__<kernel version>__]]
  14
  15 DESCRIPTION
  16 -----------
  17
  18 Create an initramfs <image> for the kernel with the version <kernel version>.
  19 If <kernel version> is omitted, then the version of the actual running
  20 kernel is used. If <image> is omitted or empty, then the default location
  21 /boot/initramfs-<kernel version>.img is used.
  22
  23 dracut creates an initial image used by the kernel for preloading the block
  24 device modules (such as IDE, SCSI or RAID) which are needed to access the root
  25 filesystem, mounting the root filesystem and booting into the real system.
  26
  27 At boot time, the kernel unpacks that archive into RAM disk, mounts and uses it
  28 as initial root file system. All finding of the root device happens in this
  29 early userspace.
  30
  31 Initramfs images are also called "initrd".
  32
  33 For a complete list of kernel command line options see *dracut.cmdline*(7).
  34
  35 If you are dropped to an emergency shell, while booting your initramfs,
  36 the file _/run/initramfs/rdsosreport.txt_ is created, which can be saved to a
  37 (to be mounted by hand) partition (usually /boot) or a USB stick.
  38 Additional debugging info can be produced by adding **rd.debug** to the kernel
  39 command line. _/run/initramfs/rdsosreport.txt_ contains all logs and the output
  40 of some tools. It should be attached to any report about dracut problems.
  41
  42 USAGE
  43 -----
  44
  45 include::dracut.usage.asc[]
  46
  47 OPTIONS
  48 -------
  49 **--kver** _<kernel version>_::
  50     set the kernel version. This enables to specify the kernel version, without
  51     specifying the location of the initramfs image. For example:
  52 ----
  53 # dracut --kver 3.5.0-0.rc7.git1.2.fc18.x86_64
  54 ----
  55
  56 **-f, --force**::
  57     overwrite existing initramfs file.
  58
  59 **-a, --add** _<list of dracut modules>_::
  60     add a space-separated list of dracut modules to the default set of modules.
  61     This parameter can be specified multiple times.
  62 +
  63 [NOTE]
  64 ===============================
  65 If [LIST] has multiple arguments, then you have to put these in quotes. For
  66 example:
  67 ----
  68 # dracut --add "module1 module2"  ...
  69 ----
  70 ===============================
  71
  72 **--force-add** _<list of dracut modules>_::
  73     force to add a space-separated list of dracut modules to the default set of
  74     modules, when -H is specified. This parameter can be specified multiple
  75     times.
  76 +
  77 [NOTE]
  78 ===============================
  79 If [LIST] has multiple arguments, then you have to put these in quotes. For
  80 example:
  81 ----
  82 # dracut --force-add "module1 module2"  ...
  83 ----
  84 ===============================
  85
  86 **-o, --omit** _<list of dracut modules>_::
  87     omit a space-separated list of dracut modules. This parameter can be
  88     specified multiple times.
  89 +
  90 [NOTE]
  91 ===============================
  92 If [LIST] has multiple arguments, then you have to put these in quotes. For
  93 example:
  94 ----
  95 # dracut --omit "module1 module2"  ...
  96 ----
  97 ===============================
  98
  99 **-m, --modules** _<list of dracut modules>_::
 100     specify a space-separated list of dracut modules to call when building the
 101     initramfs. Modules are located in _/usr/lib/dracut/modules.d_. This
 102     parameter can be specified multiple times.
 103     This option forces dracut to only include the specified dracut modules.
 104     In most cases the "--add" option is what you want to use.
 105 +
 106 [NOTE]
 107 ===============================
 108 If [LIST] has multiple arguments, then you have to put these in quotes. For
 109 example:
 110 ----
 111 # dracut --modules "module1 module2"  ...
 112 ----
 113 ===============================
 114
 115 **-d, --drivers** _<list of kernel modules>_::
 116     specify a space-separated list of kernel modules to exclusively include
 117     in the initramfs. The kernel modules have to be specified without the ".ko"
 118     suffix. This parameter can be specified multiple times.
 119 +
 120 [NOTE]
 121 ===============================
 122 If [LIST] has multiple arguments, then you have to put these in quotes. For
 123 example:
 124 ----
 125 # dracut --drivers "kmodule1 kmodule2"  ...
 126 ----
 127 ===============================
 128
 129 **--add-drivers** _<list of kernel modules>_::
 130     specify a space-separated list of kernel modules to add to the initramfs.
 131     The kernel modules have to be specified without the ".ko" suffix. This
 132     parameter can be specified multiple times.
 133 +
 134 [NOTE]
 135 ===============================
 136 If [LIST] has multiple arguments, then you have to put these in quotes. For
 137 example:
 138 ----
 139 # dracut --add-drivers "kmodule1 kmodule2"  ...
 140 ----
 141 ===============================
 142
 143 **--force-drivers** _<list of kernel modules>_::
 144     See add-drivers above. But in this case it is ensured that the drivers
 145     are tried to be loaded early via modprobe.
 146 +
 147 [NOTE]
 148 ===============================
 149 If [LIST] has multiple arguments, then you have to put these in quotes. For
 150 example:
 151 ----
 152 # dracut --force-drivers "kmodule1 kmodule2"  ...
 153 ----
 154 ===============================
 155
 156 **--omit-drivers** _<list of kernel modules>_::
 157     specify a space-separated list of kernel modules not to add to the
 158     initramfs.
 159     The kernel modules have to be specified without the ".ko" suffix. This
 160     parameter can be specified multiple times.
 161 +
 162 [NOTE]
 163 ===============================
 164 If [LIST] has multiple arguments, then you have to put these in quotes. For
 165 example:
 166 ----
 167 # dracut --omit-drivers "kmodule1 kmodule2"  ...
 168 ----
 169 ===============================
 170
 171 **--filesystems** _<list of filesystems>_::
 172     specify a space-separated list of kernel filesystem modules to exclusively
 173     include in the generic initramfs. This parameter can be specified multiple
 174     times.
 175 +
 176 [NOTE]
 177 ===============================
 178 If [LIST] has multiple arguments, then you have to put these in quotes. For
 179 example:
 180 ----
 181 # dracut --filesystems "filesystem1 filesystem2"  ...
 182 ----
 183 ===============================
 184
 185 **-k, --kmoddir** _<kernel directory>_::
 186     specify the directory, where to look for kernel modules
 187
 188 **--fwdir** _<dir>[:<dir>...]++_::
 189     specify additional directories, where to look for firmwares. This parameter
 190     can be specified multiple times.
 191
 192 **--kernel-cmdline <parameters>**::
 193     specify default kernel command line parameters
 194
 195
 196 **--kernel-only**::
 197     only install kernel drivers and firmware files
 198
 199 **--no-kernel**::
 200     do not install kernel drivers and firmware files
 201
 202 **--early-microcode**::
 203     Combine early microcode with ramdisk
 204
 205 **--no-early-microcode**::
 206     Do not combine early microcode with ramdisk
 207
 208 **--print-cmdline**::
 209     print the kernel command line for the current disk layout
 210
 211 **--mdadmconf**::
 212     include local _/etc/mdadm.conf_
 213
 214 **--nomdadmconf**::
 215     do not include local _/etc/mdadm.conf_
 216
 217 **--lvmconf**::
 218     include local _/etc/lvm/lvm.conf_
 219
 220 **--nolvmconf**::
 221     do not include local _/etc/lvm/lvm.conf_
 222
 223 **--fscks** [LIST]::
 224     add a space-separated list of fsck tools, in addition to _dracut.conf_'s
 225     specification; the installation is opportunistic (non-existing tools are
 226     ignored)
 227 +
 228 [NOTE]
 229 ===============================
 230 If [LIST] has multiple arguments, then you have to put these in quotes. For
 231 example:
 232 ----
 233 # dracut --fscks "fsck.foo barfsck"  ...
 234 ----
 235 ===============================
 236
 237 **--nofscks**::
 238     inhibit installation of any fsck tools
 239
 240 **--strip**::
 241     strip binaries in the initramfs (default)
 242
 243 **--nostrip**::
 244     do not strip binaries in the initramfs
 245
 246 **--prelink**::
 247     prelink binaries in the initramfs (default)
 248
 249 **--noprelink**::
 250     do not prelink binaries in the initramfs
 251
 252 **--hardlink**::
 253     hardlink files in the initramfs (default)
 254
 255 **--nohardlink**::
 256     do not hardlink files in the initramfs
 257
 258 **--prefix** _<dir>_::
 259     prefix initramfs files with the specified directory
 260
 261 **--noprefix**::
 262     do not prefix initramfs files (default)
 263
 264 **-h, --help**::
 265     display help text and exit.
 266
 267 **--debug**::
 268     output debug information of the build process
 269
 270 **-v, --verbose**::
 271     increase verbosity level (default is info(4))
 272
 273 **-q, --quiet**:: decrease verbosity level (default is info(4))
 274
 275 **-c, --conf** _<dracut configuration file>_::
 276     specify configuration file to use.
 277 +
 278 Default:
 279    _/etc/dracut.conf_
 280
 281 **--confdir** _<configuration directory>_::
 282     specify configuration directory to use.
 283 +
 284 Default:
 285    _/etc/dracut.conf.d_
 286
 287 **--tmpdir** _<temporary directory>_::
 288     specify temporary directory to use.
 289 +
 290 Default:
 291    _/var/tmp_
 292
 293 **--sshkey** _<sshkey file>_:: ssh key file used with ssh-client module.
 294
 295 **--logfile** _<logfile>_:: logfile to use; overrides any setting from
 296     the configuration files.
 297 +
 298 Default:
 299     _/var/log/dracut.log_
 300
 301 **-l, --local**::
 302     activates the local mode. dracut will use modules from the current working
 303     directory instead of the system-wide installed modules in
 304     _/usr/lib/dracut/modules.d_.
 305     This is useful when running dracut from a git checkout.
 306
 307 **-H, --hostonly**::
 308     Host-Only mode: Install only what is needed for booting the local host
 309     instead of a generic host and generate host-specific configuration.
 310 +
 311 [WARNING]
 312 ====
 313 If chrooted to another root other than the real root device, use "--fstab" and
 314 provide a valid _/etc/fstab_.
 315 ====
 316
 317 **-N, --no-hostonly**::
 318     Disable Host-Only mode
 319
 320 **--hostonly-cmdline**:
 321     Store kernel command line arguments needed in the initramfs
 322
 323 **--no-hostonly-cmdline**:
 324     Do not store kernel command line arguments needed in the initramfs
 325
 326 **--no-hostonly-default-device**:
 327     Do not generate implicit host devices like root, swap, fstab, etc.
 328     Use "--mount" or "--add-device" to explicitly add devices as needed.
 329
 330 **--hostonly-i18n**:
 331     Install only needed keyboard and font files according to the host configuration (default).
 332
 333 **--no-hostonly-i18n**:
 334     Install all keyboard and font files available.
 335
 336 **--persistent-policy** _<policy>_::
 337     Use _<policy>_ to address disks and partitions.
 338     _<policy>_ can be any directory name found in /dev/disk.
 339     E.g. "by-uuid", "by-label"
 340
 341 **--fstab**::
 342     Use _/etc/fstab_ instead of _/proc/self/mountinfo_.
 343
 344 **--add-fstab** _<filename>_::
 345     Add entries of _<filename>_ to the initramfs /etc/fstab.
 346
 347 **--mount** "_<device>_ _<mountpoint>_ _<filesystem type>_ [_<filesystem options>_ [_<dump frequency>_ [_<fsck order>_]]]"::
 348     Mount _<device>_ on _<mountpoint>_ with _<filesystem type>_ in the
 349     initramfs. _<filesystem options>_, _<dump options>_ and _<fsck order>_ can
 350     be specified, see fstab manpage for the details.
 351     The default _<filesystem options>_ is "defaults".
 352     The default _<dump frequency>_ is "0".
 353     the default _<fsck order>_ is "2".
 354
 355 **--mount** "_<mountpoint>_"::
 356     Like above, but _<device>_, _<filesystem type>_ and _<filesystem options>_
 357     are determined by looking at the current mounts.
 358
 359 **--add-device** _<device>_ ::
 360     Bring up _<device>_ in initramfs, _<device>_ should be the device name.
 361     This can be useful in hostonly mode for resume support when your swap is on
 362     LVM or an encrypted partition.
 363     [NB --device can be used for compatibility with earlier releases]
 364
 365 **-i, --include** _<SOURCE>_ _<TARGET>_::
 366     include the files in the SOURCE directory into the
 367     TARGET directory in the final initramfs. If SOURCE is a file, it will be
 368     installed to TARGET in the final initramfs. This parameter can be specified
 369     multiple times.
 370
 371 **-I, --install** _<file list>_::
 372     install the space separated list of files into the initramfs.
 373 +
 374 [NOTE]
 375 ===============================
 376 If [LIST] has multiple arguments, then you have to put these in quotes. For
 377 example:
 378 ----
 379 # dracut --install "/bin/foo /sbin/bar"  ...
 380 ----
 381 ===============================
 382
 383 **--install-optional** _<file list>_::
 384     install the space separated list of files into the initramfs, if they exist.
 385
 386 **--gzip**::
 387     Compress the generated initramfs using gzip. This will be done by default,
 388     unless another compression option or --no-compress is passed. Equivalent to
 389     "--compress=gzip -9"
 390
 391 **--bzip2**::
 392     Compress the generated initramfs using bzip2.
 393 +
 394 [WARNING]
 395 ====
 396 Make sure your kernel has bzip2 decompression support compiled in, otherwise you
 397 will not be able to boot. Equivalent to "--compress=bzip2"
 398 ====
 399
 400 **--lzma**::
 401     Compress the generated initramfs using lzma.
 402 +
 403 [WARNING]
 404 ====
 405 Make sure your kernel has lzma decompression support compiled in, otherwise you
 406 will not be able to boot. Equivalent to "lzma --compress=lzma -9"
 407 ====
 408
 409 **--xz**::
 410     Compress the generated initramfs using xz.
 411 +
 412 [WARNING]
 413 ====
 414 Make sure your kernel has xz decompression support compiled in, otherwise you
 415 will not be able to boot. Equivalent to
 416 "lzma --compress=xz --check=crc32 --lzma2=dict=1MiB"
 417 ====
 418
 419 **--lzo**::
 420     Compress the generated initramfs using lzop.
 421 [WARNING]
 422 ====
 423 Make sure your kernel has lzo decompression support compiled in, otherwise you
 424 will not be able to boot.
 425 ====
 426
 427 **--lz4**::
 428     Compress the generated initramfs using lz4.
 429 [WARNING]
 430 ====
 431 Make sure your kernel has lz4 decompression support compiled in, otherwise you
 432 will not be able to boot.
 433 ====
 434
 435 **--zstd**::
 436     Compress the generated initramfs using Zstandard.
 437 [WARNING]
 438 ====
 439 Make sure your kernel has zstd decompression support compiled in, otherwise you
 440 will not be able to boot.
 441 ====
 442
 443 **--compress** _<compressor>_::
 444     Compress the generated initramfs using the passed compression program. If
 445     you pass it just the name of a compression program, it will call that
 446     program with known-working arguments. If you pass a quoted string with
 447     arguments, it will be called with exactly those arguments. Depending on what
 448     you pass, this may result in an initramfs that the kernel cannot decompress.
 449     The default value can also be set via the _INITRD_COMPRESS_ environment variable.
 450
 451 **--no-compress**::
 452     Do not compress the generated initramfs. This will override any other
 453     compression options.
 454
 455 **--reproducible**::
 456     Create reproducible images.
 457
 458 **--no-reproducible**::
 459     Do not create reproducible images.
 460
 461 **--list-modules**::
 462     List all available dracut modules.
 463
 464 **-M, --show-modules**::
 465     Print included module's name to standard output during build.
 466
 467 **--keep**::
 468     Keep the initramfs temporary directory for debugging purposes.
 469
 470 **--printsize**::
 471     Print out the module install size
 472
 473 **--profile**:
 474     Output profile information of the build process
 475
 476 **--ro-mnt**:
 477     Mount / and /usr read-only by default.
 478
 479 **-L, --stdlog** _<level>_::
 480     [0-6] Specify logging level (to standard error)
 481 ----
 482           0 - suppress any messages
 483           1 - only fatal errors
 484           2 - all errors
 485           3 - warnings
 486           4 - info
 487           5 - debug info (here starts lots of output)
 488           6 - trace info (and even more)
 489 ----
 490
 491 **--regenerate-all**::
 492     Regenerate all initramfs images at the default location with the kernel
 493     versions found on the system. Additional parameters are passed through.
 494
 495 **--loginstall _<DIR>_**::
 496     Log all files installed from the host to _<DIR>_.
 497
 498 **--uefi**::
 499     Instead of creating an initramfs image, dracut will create an UEFI executable,
 500     which can be executed by an UEFI BIOS. The default output filename is
 501     _<EFI>/EFI/Linux/linux-$kernel$-<MACHINE_ID>-<BUILD_ID>.efi_. <EFI> might be
 502     _/efi_, _/boot_ or _/boot/efi_ depending on where the ESP partition is mounted.
 503     The <BUILD_ID> is taken from BUILD_ID in _/usr/lib/os-release_ or if it exists
 504     _/etc/os-release_ and is left out, if BUILD_ID is non-existant or empty.
 505
 506 **--no-machineid**::
 507     affects the default output filename of **--uefi** and will discard the <MACHINE_ID>
 508     part.
 509
 510 **--uefi-stub _<FILE>_**::
 511     Specifies the UEFI stub loader, which will load the attached kernel, initramfs and
 512     kernel command line and boots the kernel. The default is
 513     _$prefix/lib/systemd/boot/efi/linux<EFI-MACHINE-TYPE-NAME>.efi.stub_
 514     or _$prefix/lib/gummiboot/linux<EFI-MACHINE-TYPE-NAME>.efi.stub_
 515
 516 **--kernel-image _<FILE>_**::
 517     Specifies the kernel image, which to include in the UEFI executable. The default is
 518     _/lib/modules/<KERNEL-VERSION>/vmlinuz_ or _/boot/vmlinuz-<KERNEL-VERSION>_
 519
 520 ENVIRONMENT
 521 -----------
 522
 523 _INITRD_COMPRESS_::
 524     sets the default compression program. See **--compress**.
 525
 526 FILES
 527 -----
 528 _/var/log/dracut.log_::
 529     logfile of initramfs image creation
 530
 531 _/tmp/dracut.log_::
 532     logfile of initramfs image creation, if _/var/log/dracut.log_ is not
 533     writable
 534
 535 _/etc/dracut.conf_::
 536     see dracut.conf5
 537
 538 _/etc/dracut.conf.d/*.conf_::
 539     see dracut.conf5
 540
 541 _/usr/lib/dracut/dracut.conf.d/*.conf_::
 542     see dracut.conf5
 543
 544 Configuration in the initramfs
 545 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 546 _/etc/conf.d/_::
 547     Any files found in _/etc/conf.d/_ will be sourced in the initramfs to
 548     set initial values. Command line options will override these values
 549     set in the configuration files.
 550
 551 _/etc/cmdline_::
 552     Can contain additional command line options. Deprecated, better use
 553     /etc/cmdline.d/*.conf.
 554
 555 _/etc/cmdline.d/*.conf_::
 556     Can contain additional command line options.
 557
 558 AVAILABILITY
 559 ------------
 560 The dracut command is part of the dracut package and is available from
 561 link:$$https://dracut.wiki.kernel.org$$[https://dracut.wiki.kernel.org]
 562
 563 AUTHORS
 564 -------
 565 Harald Hoyer
 566
 567 Victor Lowther
 568
 569 Philippe Seewer
 570
 571 Warren Togami
 572
 573 Amadeusz Żołnowski
 574
 575 Jeremy Katz
 576
 577 David Dillow
 578
 579 Will Woods
 580
 581 SEE ALSO
 582 --------
 583 *dracut.cmdline*(7) *dracut.conf*(5) *lsinitrd*(1)