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 **--hardlink**::
 247     hardlink files in the initramfs (default)
 248
 249 **--nohardlink**::
 250     do not hardlink files in the initramfs
 251
 252 **--prefix** _<dir>_::
 253     prefix initramfs files with the specified directory
 254
 255 **--noprefix**::
 256     do not prefix initramfs files (default)
 257
 258 **-h, --help**::
 259     display help text and exit.
 260
 261 **--debug**::
 262     output debug information of the build process
 263
 264 **-v, --verbose**::
 265     increase verbosity level (default is info(4))
 266
 267 **-q, --quiet**:: decrease verbosity level (default is info(4))
 268
 269 **-c, --conf** _<dracut configuration file>_::
 270     specify configuration file to use.
 271 +
 272 Default:
 273    _/etc/dracut.conf_
 274
 275 **--confdir** _<configuration directory>_::
 276     specify configuration directory to use.
 277 +
 278 Default:
 279    _/etc/dracut.conf.d_
 280
 281 **--tmpdir** _<temporary directory>_::
 282     specify temporary directory to use.
 283 +
 284 Default:
 285    _/var/tmp_
 286
 287 **--sshkey** _<sshkey file>_:: ssh key file used with ssh-client module.
 288
 289 **--logfile** _<logfile>_:: logfile to use; overrides any setting from
 290     the configuration files.
 291 +
 292 Default:
 293     _/var/log/dracut.log_
 294
 295 **-l, --local**::
 296     activates the local mode. dracut will use modules from the current working
 297     directory instead of the system-wide installed modules in
 298     _/usr/lib/dracut/modules.d_.
 299     This is useful when running dracut from a git checkout.
 300
 301 **-H, --hostonly**::
 302     Host-Only mode: Install only what is needed for booting the local host
 303     instead of a generic host and generate host-specific configuration.
 304 +
 305 [WARNING]
 306 ====
 307 If chrooted to another root other than the real root device, use "--fstab" and
 308 provide a valid _/etc/fstab_.
 309 ====
 310
 311 **-N, --no-hostonly**::
 312     Disable Host-Only mode
 313
 314 **--hostonly-cmdline**:
 315     Store kernel command line arguments needed in the initramfs
 316
 317 **--no-hostonly-cmdline**:
 318     Do not store kernel command line arguments needed in the initramfs
 319
 320 **--no-hostonly-default-device**:
 321     Do not generate implicit host devices like root, swap, fstab, etc.
 322     Use "--mount" or "--add-device" to explicitly add devices as needed.
 323
 324 **--hostonly-i18n**:
 325     Install only needed keyboard and font files according to the host configuration (default).
 326
 327 **--no-hostonly-i18n**:
 328     Install all keyboard and font files available.
 329
 330 **--persistent-policy** _<policy>_::
 331     Use _<policy>_ to address disks and partitions.
 332     _<policy>_ can be any directory name found in /dev/disk.
 333     E.g. "by-uuid", "by-label"
 334
 335 **--fstab**::
 336     Use _/etc/fstab_ instead of _/proc/self/mountinfo_.
 337
 338 **--add-fstab** _<filename>_::
 339     Add entries of _<filename>_ to the initramfs /etc/fstab.
 340
 341 **--mount** "_<device>_ _<mountpoint>_ _<filesystem type>_ [_<filesystem options>_ [_<dump frequency>_ [_<fsck order>_]]]"::
 342     Mount _<device>_ on _<mountpoint>_ with _<filesystem type>_ in the
 343     initramfs. _<filesystem options>_, _<dump options>_ and _<fsck order>_ can
 344     be specified, see fstab manpage for the details.
 345     The default _<filesystem options>_ is "defaults".
 346     The default _<dump frequency>_ is "0".
 347     the default _<fsck order>_ is "2".
 348
 349 **--mount** "_<mountpoint>_"::
 350     Like above, but _<device>_, _<filesystem type>_ and _<filesystem options>_
 351     are determined by looking at the current mounts.
 352
 353 **--add-device** _<device>_ ::
 354     Bring up _<device>_ in initramfs, _<device>_ should be the device name.
 355     This can be useful in hostonly mode for resume support when your swap is on
 356     LVM or an encrypted partition.
 357     [NB --device can be used for compatibility with earlier releases]
 358
 359 **-i, --include** _<SOURCE>_ _<TARGET>_::
 360     include the files in the SOURCE directory into the
 361     TARGET directory in the final initramfs. If SOURCE is a file, it will be
 362     installed to TARGET in the final initramfs. This parameter can be specified
 363     multiple times.
 364
 365 **-I, --install** _<file list>_::
 366     install the space separated list of files into the initramfs.
 367 +
 368 [NOTE]
 369 ===============================
 370 If [LIST] has multiple arguments, then you have to put these in quotes. For
 371 example:
 372 ----
 373 # dracut --install "/bin/foo /sbin/bar"  ...
 374 ----
 375 ===============================
 376
 377 **--install-optional** _<file list>_::
 378     install the space separated list of files into the initramfs, if they exist.
 379
 380 **--gzip**::
 381     Compress the generated initramfs using gzip. This will be done by default,
 382     unless another compression option or --no-compress is passed. Equivalent to
 383     "--compress=gzip -9"
 384
 385 **--bzip2**::
 386     Compress the generated initramfs using bzip2.
 387 +
 388 [WARNING]
 389 ====
 390 Make sure your kernel has bzip2 decompression support compiled in, otherwise you
 391 will not be able to boot. Equivalent to "--compress=bzip2"
 392 ====
 393
 394 **--lzma**::
 395     Compress the generated initramfs using lzma.
 396 +
 397 [WARNING]
 398 ====
 399 Make sure your kernel has lzma decompression support compiled in, otherwise you
 400 will not be able to boot. Equivalent to "lzma --compress=lzma -9"
 401 ====
 402
 403 **--xz**::
 404     Compress the generated initramfs using xz.
 405 +
 406 [WARNING]
 407 ====
 408 Make sure your kernel has xz decompression support compiled in, otherwise you
 409 will not be able to boot. Equivalent to
 410 "lzma --compress=xz --check=crc32 --lzma2=dict=1MiB"
 411 ====
 412
 413 **--lzo**::
 414     Compress the generated initramfs using lzop.
 415 [WARNING]
 416 ====
 417 Make sure your kernel has lzo decompression support compiled in, otherwise you
 418 will not be able to boot.
 419 ====
 420
 421 **--lz4**::
 422     Compress the generated initramfs using lz4.
 423 [WARNING]
 424 ====
 425 Make sure your kernel has lz4 decompression support compiled in, otherwise you
 426 will not be able to boot.
 427 ====
 428
 429 **--zstd**::
 430     Compress the generated initramfs using Zstandard.
 431 [WARNING]
 432 ====
 433 Make sure your kernel has zstd decompression support compiled in, otherwise you
 434 will not be able to boot.
 435 ====
 436
 437 **--compress** _<compressor>_::
 438     Compress the generated initramfs using the passed compression program. If
 439     you pass it just the name of a compression program, it will call that
 440     program with known-working arguments. If you pass a quoted string with
 441     arguments, it will be called with exactly those arguments. Depending on what
 442     you pass, this may result in an initramfs that the kernel cannot decompress.
 443     The default value can also be set via the _INITRD_COMPRESS_ environment variable.
 444
 445 **--no-compress**::
 446     Do not compress the generated initramfs. This will override any other
 447     compression options.
 448
 449 **--reproducible**::
 450     Create reproducible images.
 451
 452 **--no-reproducible**::
 453     Do not create reproducible images.
 454
 455 **--list-modules**::
 456     List all available dracut modules.
 457
 458 **-M, --show-modules**::
 459     Print included module's name to standard output during build.
 460
 461 **--keep**::
 462     Keep the initramfs temporary directory for debugging purposes.
 463
 464 **--printsize**::
 465     Print out the module install size
 466
 467 **--profile**:
 468     Output profile information of the build process
 469
 470 **--ro-mnt**:
 471     Mount / and /usr read-only by default.
 472
 473 **-L, --stdlog** _<level>_::
 474     [0-6] Specify logging level (to standard error)
 475 ----
 476           0 - suppress any messages
 477           1 - only fatal errors
 478           2 - all errors
 479           3 - warnings
 480           4 - info
 481           5 - debug info (here starts lots of output)
 482           6 - trace info (and even more)
 483 ----
 484
 485 **--regenerate-all**::
 486     Regenerate all initramfs images at the default location with the kernel
 487     versions found on the system. Additional parameters are passed through.
 488
 489 **--loginstall _<DIR>_**::
 490     Log all files installed from the host to _<DIR>_.
 491
 492 **--uefi**::
 493     Instead of creating an initramfs image, dracut will create an UEFI executable,
 494     which can be executed by an UEFI BIOS. The default output filename is
 495     _<EFI>/EFI/Linux/linux-$kernel$-<MACHINE_ID>-<BUILD_ID>.efi_. <EFI> might be
 496     _/efi_, _/boot_ or _/boot/efi_ depending on where the ESP partition is mounted.
 497     The <BUILD_ID> is taken from BUILD_ID in _/usr/lib/os-release_ or if it exists
 498     _/etc/os-release_ and is left out, if BUILD_ID is non-existant or empty.
 499
 500 **--no-machineid**::
 501     affects the default output filename of **--uefi** and will discard the <MACHINE_ID>
 502     part.
 503
 504 **--uefi-stub _<FILE>_**::
 505     Specifies the UEFI stub loader, which will load the attached kernel, initramfs and
 506     kernel command line and boots the kernel. The default is
 507     _$prefix/lib/systemd/boot/efi/linux<EFI-MACHINE-TYPE-NAME>.efi.stub_
 508     or _$prefix/lib/gummiboot/linux<EFI-MACHINE-TYPE-NAME>.efi.stub_
 509
 510 **--kernel-image _<FILE>_**::
 511     Specifies the kernel image, which to include in the UEFI executable. The default is
 512     _/lib/modules/<KERNEL-VERSION>/vmlinuz_ or _/boot/vmlinuz-<KERNEL-VERSION>_
 513
 514 ENVIRONMENT
 515 -----------
 516
 517 _INITRD_COMPRESS_::
 518     sets the default compression program. See **--compress**.
 519
 520 FILES
 521 -----
 522 _/var/log/dracut.log_::
 523     logfile of initramfs image creation
 524
 525 _/tmp/dracut.log_::
 526     logfile of initramfs image creation, if _/var/log/dracut.log_ is not
 527     writable
 528
 529 _/etc/dracut.conf_::
 530     see dracut.conf5
 531
 532 _/etc/dracut.conf.d/*.conf_::
 533     see dracut.conf5
 534
 535 _/usr/lib/dracut/dracut.conf.d/*.conf_::
 536     see dracut.conf5
 537
 538 Configuration in the initramfs
 539 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 540 _/etc/conf.d/_::
 541     Any files found in _/etc/conf.d/_ will be sourced in the initramfs to
 542     set initial values. Command line options will override these values
 543     set in the configuration files.
 544
 545 _/etc/cmdline_::
 546     Can contain additional command line options. Deprecated, better use
 547     /etc/cmdline.d/*.conf.
 548
 549 _/etc/cmdline.d/*.conf_::
 550     Can contain additional command line options.
 551
 552 AVAILABILITY
 553 ------------
 554 The dracut command is part of the dracut package and is available from
 555 link:$$https://dracut.wiki.kernel.org$$[https://dracut.wiki.kernel.org]
 556
 557 AUTHORS
 558 -------
 559 Harald Hoyer
 560
 561 Victor Lowther
 562
 563 Philippe Seewer
 564
 565 Warren Togami
 566
 567 Amadeusz Żołnowski
 568
 569 Jeremy Katz
 570
 571 David Dillow
 572
 573 Will Woods
 574
 575 SEE ALSO
 576 --------
 577 *dracut.cmdline*(7) *dracut.conf*(5) *lsinitrd*(1)