|
|
|
To create a initramfs image, the most simple command is:
|
|
|
|
----
|
|
|
|
# dracut
|
|
|
|
----
|
|
|
|
|
|
|
|
This will generate a general purpose initramfs image, with all possible
|
|
|
|
functionality resulting of the combination of the installed dracut modules and
|
|
|
|
system tools. The image is /boot/initramfs-_++<kernel version>++_.img and
|
|
|
|
contains the kernel modules of the currently active kernel with version
|
|
|
|
_++<kernel version>++_.
|
|
|
|
|
|
|
|
If the initramfs image already exists, dracut will display an error message, and
|
|
|
|
to overwrite the existing image, you have to use the --force option.
|
|
|
|
----
|
|
|
|
# dracut --force
|
|
|
|
----
|
|
|
|
|
|
|
|
If you want to specify another filename for the resulting image you would issue
|
|
|
|
a command like:
|
|
|
|
----
|
|
|
|
# dracut foobar.img
|
|
|
|
----
|
|
|
|
|
|
|
|
To generate an image for a specific kernel version, the command would be:
|
|
|
|
----
|
|
|
|
# dracut foobar.img 2.6.40-1.rc5.f20
|
|
|
|
----
|
|
|
|
|
|
|
|
A shortcut to generate the image at the default location for a specific kernel
|
|
|
|
version is:
|
|
|
|
----
|
|
|
|
# dracut --kver 2.6.40-1.rc5.f20
|
|
|
|
----
|
|
|
|
|
|
|
|
If you want to create lighter, smaller initramfs images, you may want to specify
|
|
|
|
the --hostonly or -H option. Using this option, the resulting image will
|
|
|
|
contain only those dracut modules, kernel modules and filesystems, which are
|
|
|
|
needed to boot this specific machine. This has the drawback, that you can't put
|
|
|
|
the disk on another controller or machine, and that you can't switch to another
|
|
|
|
root filesystem, without recreating the initramfs image. The usage of the
|
|
|
|
--hostonly option is only for experts and you will have to keep the broken
|
|
|
|
pieces. At least keep a copy of a general purpose image (and corresponding
|
|
|
|
kernel) as a fallback to rescue your system.
|
|
|
|
|
|
|
|
=== Inspecting the Contents
|
|
|
|
To see the contents of the image created by dracut, you can use the lsinitrd
|
|
|
|
tool.
|
|
|
|
----
|
|
|
|
# lsinitrd | less
|
|
|
|
----
|
|
|
|
|
|
|
|
To display the contents of a file in the initramfs also use the lsinitrd tool:
|
|
|
|
----
|
|
|
|
# lsinitrd -f /etc/ld.so.conf
|
|
|
|
include ld.so.conf.d/*.conf
|
|
|
|
----
|
|
|
|
|
|
|
|
=== Adding dracut Modules
|
|
|
|
Some dracut modules are turned off by default and have to be activated manually.
|
|
|
|
You can do this by adding the dracut modules to the configuration file
|
|
|
|
_/etc/dracut.conf_ or _/etc/dracut.conf.d/myconf.conf_. See *dracut.conf*(5).
|
|
|
|
You can also add dracut modules on the command line
|
|
|
|
by using the -a or --add option:
|
|
|
|
----
|
|
|
|
# dracut --add module initramfs-module.img
|
|
|
|
----
|
|
|
|
|
|
|
|
To see a list of available dracut modules, use the --list-modules option:
|
|
|
|
----
|
|
|
|
# dracut --list-modules
|
|
|
|
----
|
|
|
|
|
|
|
|
=== Omitting dracut Modules
|
|
|
|
Sometimes you don't want a dracut module to be included for reasons of speed,
|
|
|
|
size or functionality. To do this, either specify the omit_dracutmodules
|
|
|
|
variable in the _dracut.conf_ or _/etc/dracut.conf.d/myconf.conf_ configuration
|
|
|
|
file (see *dracut.conf*(5)), or use the -o or --omit option
|
|
|
|
on the command line:
|
|
|
|
----
|
|
|
|
# dracut -o "multipath lvm" no-multipath-lvm.img
|
|
|
|
----
|
|
|
|
|
|
|
|
=== Adding Kernel Modules
|
|
|
|
If you need a special kernel module in the initramfs, which is not
|
|
|
|
automatically picked up by dracut, you have the use the --add-drivers option
|
|
|
|
on the command line or the drivers variable in the _/etc/dracut.conf_
|
|
|
|
or _/etc/dracut.conf.d/myconf.conf_ configuration file (see *dracut.conf*(5)):
|
|
|
|
----
|
|
|
|
# dracut --add-drivers mymod initramfs-with-mymod.img
|
|
|
|
----
|
|
|
|
|
|
|
|
=== Boot parameters
|
|
|
|
An initramfs generated without the "hostonly" mode, does not contain any system
|
|
|
|
configuration files (except for some special exceptions), so the configuration
|
|
|
|
has to be done on the kernel command line. With this flexibility, you can easily
|
|
|
|
boot from a changed root partition, without the need to recompile the initramfs
|
|
|
|
image. So, you could completely change your root partition (move it inside a md
|
|
|
|
raid with encryption and LVM on top), as long as you specify the correct
|
|
|
|
filesystem LABEL or UUID on the kernel command line for your root device, dracut
|
|
|
|
will find it and boot from it.
|
|
|
|
|
|
|
|
The kernel command line can also be provided by the dhcp server with the
|
|
|
|
root-path option. See <<NetworkBoot>>.
|
|
|
|
|
|
|
|
For a full reference of all kernel command line parameters,
|
|
|
|
see *dracut.cmdline*(5).
|
|
|
|
|
|
|
|
To get a quick start for the suitable kernel command line on your system,
|
|
|
|
use the __--print-cmdline__ option:
|
|
|
|
----
|
|
|
|
# dracut --print-cmdline
|
|
|
|
root=UUID=8b8b6f91-95c7-4da2-831b-171e12179081 rootflags=rw,relatime,discard,data=ordered rootfstype=ext4
|
|
|
|
----
|
|
|
|
|
|
|
|
==== Specifying the root Device
|
|
|
|
This is the only option dracut really needs to boot from your root partition.
|
|
|
|
Because your root partition can live in various environments, there are a lot of
|
|
|
|
formats for the root= option. The most basic one is root=_++<path to device
|
|
|
|
node>++_:
|
|
|
|
----
|
|
|
|
root=/dev/sda2
|
|
|
|
----
|
|
|
|
|
|
|
|
Because device node names can change, dependent on the drive ordering, you are
|
|
|
|
encouraged to use the filesystem identifier (UUID) or filesystem label (LABEL)
|
|
|
|
to specify your root partition:
|
|
|
|
----
|
|
|
|
root=UUID=19e9dda3-5a38-484d-a9b0-fa6b067d0331
|
|
|
|
----
|
|
|
|
|
|
|
|
or
|
|
|
|
|
|
|
|
----
|
|
|
|
root=LABEL=myrootpartitionlabel
|
|
|
|
----
|
|
|
|
|
|
|
|
To see all UUIDs or LABELs on your system, do:
|
|
|
|
----
|
|
|
|
# ls -l /dev/disk/by-uuid
|
|
|
|
----
|
|
|
|
|
|
|
|
or
|
|
|
|
|
|
|
|
----
|
|
|
|
# ls -l /dev/disk/by-label
|
|
|
|
----
|
|
|
|
|
|
|
|
If your root partition is on the network see <<NetworkBoot>>.
|
|
|
|
|
|
|
|
==== Keyboard Settings
|
|
|
|
If you have to input passwords for encrypted disk volumes, you might want to set
|
|
|
|
the keyboard layout and specify a display font.
|
|
|
|
|
|
|
|
A typical german kernel command line would contain:
|
|
|
|
----
|
|
|
|
rd.vconsole.font=eurlatgr rd.vconsole.keymap=de-latin1-nodeadkeys rd.locale.LANG=de_DE.UTF-8
|
|
|
|
----
|
|
|
|
|
|
|
|
Setting these options can override the setting stored on your system, if you use
|
|
|
|
a modern init system, like systemd.
|
|
|
|
|
|
|
|
==== Blacklisting Kernel Modules
|
|
|
|
Sometimes it is required to prevent the automatic kernel module loading of a
|
|
|
|
specific kernel module. To do this, just add rd.blacklist=_++<kernel module
|
|
|
|
name>++_, with _++<kernel module name>++_ not containing the _.ko_
|
|
|
|
suffix, to the kernel command line. For example:
|
|
|
|
----
|
|
|
|
rd.driver.blacklist=mptsas rd.driver.blacklist=nouveau
|
|
|
|
----
|
|
|
|
|
|
|
|
The option can be specified multiple times on the kernel command line.
|
|
|
|
|
|
|
|
==== Speeding up the Boot Process
|
|
|
|
If you want to speed up the boot process, you can specify as much information
|
|
|
|
for dracut on the kernel command as possible. For example, you can tell dracut,
|
|
|
|
that you root partition is not on a LVM volume or not on a raid partition, or
|
|
|
|
that it lives inside a specific crypto LUKS encrypted volume. By default, dracut
|
|
|
|
searches everywhere. A typical dracut kernel command line for a plain primary or
|
|
|
|
logical partition would contain:
|
|
|
|
----
|
|
|
|
rd.luks=0 rd.lvm=0 rd.md=0 rd.dm=0
|
|
|
|
----
|
|
|
|
|
|
|
|
This turns off every automatic assembly of LVM, MD raids, DM raids and
|
|
|
|
crypto LUKS.
|
|
|
|
|
|
|
|
Of course, you could also omit the dracut modules in the initramfs creation
|
|
|
|
process, but then you would lose the possibility to turn it on on demand.
|
|
|
|
|
|
|
|
|
|
|
|
[[Injecting]]
|
|
|
|
=== Injecting custom Files
|
|
|
|
To add your own files to the initramfs image, you have several possibilities.
|
|
|
|
|
|
|
|
The --include option let you specify a source path and a target path.
|
|
|
|
For example
|
|
|
|
----
|
|
|
|
# dracut --include cmdline-preset /etc/cmdline.d/mycmdline.conf initramfs-cmdline-pre.img
|
|
|
|
----
|
|
|
|
will create an initramfs image, where the file cmdline-preset will be copied
|
|
|
|
inside the initramfs to _/etc/cmdline.d/mycmdline.conf_. --include can only
|
|
|
|
be specified once.
|
|
|
|
|
|
|
|
|
|
|
|
----
|
|
|
|
# mkdir -p rd.live.overlay/etc/cmdline.d
|
|
|
|
# mkdir -p rd.live.overlay/etc/conf.d
|
|
|
|
# echo "ip=dhcp" >> rd.live.overlay/etc/cmdline.d/mycmdline.conf
|
|
|
|
# echo export FOO=testtest >> rd.live.overlay/etc/conf.d/testvar.conf
|
|
|
|
# echo export BAR=testtest >> rd.live.overlay/etc/conf.d/testvar.conf
|
|
|
|
# tree rd.live.overlay/
|
|
|
|
rd.live.overlay/
|
|
|
|
`-- etc
|
|
|
|
|-- cmdline.d
|
|
|
|
| `-- mycmdline.conf
|
|
|
|
`-- conf.d
|
|
|
|
`-- testvar.conf
|
|
|
|
|
|
|
|
# dracut --include rd.live.overlay / initramfs-rd.live.overlay.img
|
|
|
|
----
|
|
|
|
|
|
|
|
This will put the contents of the rd.live.overlay directory into the root of the
|
|
|
|
initramfs image.
|
|
|
|
|
|
|
|
The --install option let you specify several files, which will get installed in
|
|
|
|
the initramfs image at the same location, as they are present on initramfs
|
|
|
|
creation time.
|
|
|
|
|
|
|
|
|
|
|
|
----
|
|
|
|
# dracut --install 'strace fsck.ext3 ssh' initramfs-dbg.img
|
|
|
|
----
|
|
|
|
|
|
|
|
This will create an initramfs with the strace, fsck.ext3 and ssh executables,
|
|
|
|
together with the libraries needed to start those. The --install option can be
|
|
|
|
specified multiple times.
|
|
|
|
|
|
|
|
|
|
|
|
[[NetworkBoot]]
|
|
|
|
=== Network Boot
|
|
|
|
|
|
|
|
If your root partition is on a network drive, you have to have the network
|
|
|
|
dracut modules installed to create a network aware initramfs image.
|
|
|
|
|
|
|
|
If you specify ip=dhcp on the kernel command line, then dracut asks a dhcp
|
|
|
|
server about the ip address for the machine. The dhcp server can also serve an
|
|
|
|
additional root-path, which will set the root device for dracut. With this
|
|
|
|
mechanism, you have static configuration on your client machine and a
|
|
|
|
centralized boot configuration on your TFTP/DHCP server. If you can't pass a
|
|
|
|
kernel command line, then you can inject _/etc/cmdline.d/mycmdline.conf_, with a
|
|
|
|
method described in <<Injecting>>.
|
|
|
|
|
|
|
|
==== Reducing the Image Size
|
|
|
|
|
|
|
|
To reduce the size of the initramfs, you should create it with by omitting all
|
|
|
|
dracut modules, which you know, you don't need to boot the machine.
|
|
|
|
|
|
|
|
You can also specify the exact dracut and kernel modules to produce a very tiny
|
|
|
|
initramfs image.
|
|
|
|
|
|
|
|
For example for a NFS image, you would do:
|
|
|
|
|
|
|
|
|
|
|
|
----
|
|
|
|
# dracut -m "nfs network base" initramfs-nfs-only.img
|
|
|
|
----
|
|
|
|
|
|
|
|
Then you would boot from this image with your target machine and reduce the size
|
|
|
|
once more by creating it on the target machine with the --host-only option:
|
|
|
|
|
|
|
|
|
|
|
|
----
|
|
|
|
# dracut -m "nfs network base" --host-only initramfs-nfs-host-only.img
|
|
|
|
----
|
|
|
|
|
|
|
|
This will reduce the size of the initramfs image significantly.
|
|
|
|
|
|
|
|
|
|
|
|
== Troubleshooting
|
|
|
|
|
|
|
|
If the boot process does not succeed, you have several options to debug the
|
|
|
|
situation. Some of the basic operations are covered here. For more information
|
|
|
|
you should also visit:
|
|
|
|
https://www.kernel.org/pub/linux/utils/boot/dracut/dracut.html
|
|
|
|
|
|
|
|
|
|
|
|
[[identifying-your-problem-area]]
|
|
|
|
=== Identifying your problem area
|
|
|
|
. Remove ''rhgb'' and ''quiet'' from the kernel command line
|
|
|
|
. Add ''rd.shell'' to the kernel command line. This will present a shell should
|
|
|
|
dracut be unable to locate your root device
|
|
|
|
. Add ''rd.shell rd.debug log_buf_len=1M'' to the kernel command line so that
|
|
|
|
dracut shell commands are printed as they are executed
|
|
|
|
. The file /run/initramfs/rdsosreport.txt is generated,
|
|
|
|
which contains all the logs and the output of all significant tools, which are
|
|
|
|
mentioned later.
|
|
|
|
|
|
|
|
If you want to save that output, simply mount /boot by hand or insert an USB
|
|
|
|
stick and mount that. Then you can store the output for later inspection.
|
|
|
|
|
|
|
|
[[information-to-include-in-your-report]]
|
|
|
|
=== Information to include in your report
|
|
|
|
|
|
|
|
[[all-bug-reports]]
|
|
|
|
==== All bug reports
|
|
|
|
In all cases, the following should be mentioned and attached to your bug report:
|
|
|
|
|
|
|
|
* The exact kernel command-line used. Typically from the bootloader
|
|
|
|
configuration file (e.g. _/boot/grub2/grub.cfg_) or from _/proc/cmdline_.
|
|
|
|
* A copy of your disk partition information from _/etc/fstab_, which might be
|
|
|
|
obtained booting an old working initramfs or a rescue medium.
|
|
|
|
* Turn on dracut debugging (see _the 'debugging dracut' section_), and attach
|
|
|
|
the file /run/initramfs/rdsosreport.txt.
|
|
|
|
* If you use a dracut configuration file, please include _/etc/dracut.conf_ and
|
|
|
|
all files in _/etc/dracut.conf.d/*.conf_
|
|
|
|
|
|
|
|
[[network-root-device-related-problems]]
|
|
|
|
==== Network root device related problems
|
|
|
|
This section details information to include when experiencing problems on a
|
|
|
|
system whose root device is located on a network attached volume (e.g. iSCSI,
|
|
|
|
NFS or NBD). As well as the information from <<all-bug-reports>>, include the
|
|
|
|
following information:
|
|
|
|
|
|
|
|
|
|
|
|
* Please include the output of
|
|
|
|
+
|
|
|
|
----
|
|
|
|
# /sbin/ifup <interfacename>
|
|
|
|
# ip addr show
|
|
|
|
----
|
|
|
|
|
|
|
|
[[debugging-dracut]]
|
|
|
|
=== Debugging dracut
|
|
|
|
|
|
|
|
|
|
|
|
[[configure-a-serial-console]]
|
|
|
|
==== Configure a serial console
|
|
|
|
|
|
|
|
Successfully debugging dracut will require some form of console
|
|
|
|
logging during the system boot. This section documents configuring a
|
|
|
|
serial console connection to record boot messages.
|
|
|
|
|
|
|
|
. First, enable serial console output for both the kernel and the bootloader.
|
|
|
|
. Open the file _/boot/grub2/grub.cfg_ for editing. Below the line ''timeout=5'', add
|
|
|
|
the following:
|
|
|
|
+
|
|
|
|
----
|
|
|
|
serial --unit=0 --speed=9600
|
|
|
|
terminal --timeout=5 serial console
|
|
|
|
----
|
|
|
|
+
|
|
|
|
. Also in _/boot/grub2/grub.cfg_, add the following boot arguments to the ''kernel''
|
|
|
|
line:
|
|
|
|
+
|
|
|
|
----
|
|
|
|
console=tty0 console=ttyS0,9600
|
|
|
|
----
|
|
|
|
+
|
|
|
|
. When finished, the _/boot/grub2/grub.cfg_ file should look similar to the example
|
|
|
|
below.
|
|
|
|
+
|
|
|
|
----
|
|
|
|
default=0
|
|
|
|
timeout=5
|
|
|
|
serial --unit=0 --speed=9600
|
|
|
|
terminal --timeout=5 serial console
|
|
|
|
title Fedora (2.6.29.5-191.fc11.x86_64)
|
|
|
|
root (hd0,0)
|
|
|
|
kernel /vmlinuz-2.6.29.5-191.fc11.x86_64 ro root=/dev/mapper/vg_uc1-lv_root console=tty0 console=ttyS0,9600
|
|
|
|
initrd /dracut-2.6.29.5-191.fc11.x86_64.img
|
|
|
|
----
|
|
|
|
+
|
|
|
|
. More detailed information on how to configure the kernel for console output
|
|
|
|
can be found at
|
|
|
|
http://www.faqs.org/docs/Linux-HOWTO/Remote-Serial-Console-HOWTO.html#CONFIGURE-KERNEL.
|
|
|
|
. Redirecting non-interactive output
|
|
|
|
+
|
|
|
|
--
|
|
|
|
NOTE: You can redirect all non-interactive output to _/dev/kmsg_ and the kernel
|
|
|
|
will put it out on the console when it reaches the kernel buffer by doing
|
|
|
|
|
|
|
|
----
|
|
|
|
# exec >/dev/kmsg 2>&1 </dev/console
|
|
|
|
----
|
|
|
|
--
|
|
|
|
|
|
|
|
[[using-the-dracut-shell]]
|
|
|
|
==== Using the dracut shell
|
|
|
|
|
|
|
|
dracut offers a shell for interactive debugging in the event dracut fails to
|
|
|
|
locate your root filesystem. To enable the shell:
|
|
|
|
|
|
|
|
. Add the boot parameter ''rd.shell'' to your bootloader configuration file
|
|
|
|
(e.g. _/boot/grub2/grub.cfg_)
|
|
|
|
. Remove the boot arguments ''rhgb'' and ''quiet''
|
|
|
|
+
|
|
|
|
A sample _/boot/grub2/grub.cfg_ bootloader configuration file is listed below.
|
|
|
|
+
|
|
|
|
----
|
|
|
|
default=0
|
|
|
|
timeout=5
|
|
|
|
serial --unit=0 --speed=9600
|
|
|
|
terminal --timeout=5 serial console
|
|
|
|
title Fedora (2.6.29.5-191.fc11.x86_64)
|
|
|
|
root (hd0,0)
|
|
|
|
kernel /vmlinuz-2.6.29.5-191.fc11.x86_64 ro root=/dev/mapper/vg_uc1-lv_root console=tty0 rd.shell
|
|
|
|
initrd /dracut-2.6.29.5-191.fc11.x86_64.img
|
|
|
|
----
|
|
|
|
+
|
|
|
|
. If system boot fails, you will be dropped into a shell as seen in the example
|
|
|
|
below.
|
|
|
|
+
|
|
|
|
----
|
|
|
|
No root device found
|
|
|
|
Dropping to debug shell.
|
|
|
|
|
|
|
|
#
|
|
|
|
----
|
|
|
|
+
|
|
|
|
. Use this shell prompt to gather the information requested above
|
|
|
|
(see <<all-bug-reports>>).
|
|
|
|
|
|
|
|
[[accessing-the-root-volume-from-the-dracut-shell]]
|
|
|
|
==== Accessing the root volume from the dracut shell
|
|
|
|
From the dracut debug shell, you can manually perform the task of locating and
|
|
|
|
preparing your root volume for boot. The required steps will depend on how your
|
|
|
|
root volume is configured. Common scenarios include:
|
|
|
|
|
|
|
|
* A block device (e.g. _/dev/sda7_)
|
|
|
|
* A LVM logical volume (e.g. _/dev/VolGroup00/LogVol00_)
|
|
|
|
* An encrypted device
|
|
|
|
(e.g. _/dev/mapper/luks-4d5972ea-901c-4584-bd75-1da802417d83_)
|
|
|
|
* A network attached device
|
|
|
|
(e.g. _netroot=iscsi:@192.168.0.4::3260::iqn.2009-02.org.example:for.all_)
|
|
|
|
|
|
|
|
The exact method for locating and preparing will vary. However, to continue with
|
|
|
|
a successful boot, the objective is to locate your root volume and create a
|
|
|
|
symlink _/dev/root_ which points to the file system. For example, the following
|
|
|
|
example demonstrates accessing and booting a root volume that is an encrypted
|
|
|
|
LVM Logical volume.
|
|
|
|
|
|
|
|
. Inspect your partitions using parted
|
|
|
|
+
|
|
|
|
----
|
|
|
|
# parted /dev/sda -s p
|
|
|
|
Model: ATA HTS541060G9AT00 (scsi)
|
|
|
|
Disk /dev/sda: 60.0GB
|
|
|
|
Sector size (logical/physical): 512B/512B
|
|
|
|
Partition Table: msdos
|
|
|
|
Number Start End Size Type File system Flags
|
|
|
|
1 32.3kB 10.8GB 107MB primary ext4 boot
|
|
|
|
2 10.8GB 55.6GB 44.7GB logical lvm
|
|
|
|
----
|
|
|
|
+
|
|
|
|
. You recall that your root volume was a LVM logical volume. Scan and activate
|
|
|
|
any logical volumes.
|
|
|
|
+
|
|
|
|
----
|
|
|
|
# lvm vgscan
|
|
|
|
# lvm vgchange -ay
|
|
|
|
----
|
|
|
|
+
|
|
|
|
. You should see any logical volumes now using the command blkid:
|
|
|
|
+
|
|
|
|
----
|
|
|
|
# blkid
|
|
|
|
/dev/sda1: UUID="3de247f3-5de4-4a44-afc5-1fe179750cf7" TYPE="ext4"
|
|
|
|
/dev/sda2: UUID="Ek4dQw-cOtq-5MJu-OGRF-xz5k-O2l8-wdDj0I" TYPE="LVM2_member"
|
|
|
|
/dev/mapper/linux-root: UUID="def0269e-424b-4752-acf3-1077bf96ad2c" TYPE="crypto_LUKS"
|
|
|
|
/dev/mapper/linux-home: UUID="c69127c1-f153-4ea2-b58e-4cbfa9257c5e" TYPE="ext3"
|
|
|
|
/dev/mapper/linux-swap: UUID="47b4d329-975c-4c08-b218-f9c9bf3635f1" TYPE="swap"
|
|
|
|
----
|
|
|
|
+
|
|
|
|
. From the output above, you recall that your root volume exists on an encrypted
|
|
|
|
block device. Following the guidance disk encryption guidance from the
|
|
|
|
Installation Guide, you unlock your encrypted root volume.
|
|
|
|
+
|
|
|
|
----
|
|
|
|
# UUID=$(cryptsetup luksUUID /dev/mapper/linux-root)
|
|
|
|
# cryptsetup luksOpen /dev/mapper/linux-root luks-$UUID
|
|
|
|
Enter passphrase for /dev/mapper/linux-root:
|
|
|
|
Key slot 0 unlocked.
|
|
|
|
----
|
|
|
|
+
|
|
|
|
. Next, make a symbolic link to the unlocked root volume
|
|
|
|
+
|
|
|
|
----
|
|
|
|
# ln -s /dev/mapper/luks-$UUID /dev/root
|
|
|
|
----
|
|
|
|
+
|
|
|
|
. With the root volume available, you may continue booting the system by exiting
|
|
|
|
the dracut shell
|
|
|
|
+
|
|
|
|
----
|
|
|
|
# exit
|
|
|
|
----
|
|
|
|
|
|
|
|
[[additional-dracut-boot-parameters]]
|
|
|
|
==== Additional dracut boot parameters
|
|
|
|
For more debugging options, see *dracut.cmdline*(7).
|
|
|
|
|
|
|
|
|
|
|
|
[[debugging-dracut-on-shutdown]]
|
|
|
|
==== Debugging dracut on shutdown
|
|
|
|
|
|
|
|
To debug the shutdown sequence on systemd systems, you can _rd.break_
|
|
|
|
on _pre-shutdown_ or _shutdown_.
|
|
|
|
|
|
|
|
To do this from an already booted system:
|
|
|
|
----
|
|
|
|
# mkdir -p /run/initramfs/etc/cmdline.d
|
|
|
|
# echo "rd.debug rd.break=pre-shutdown rd.break=shutdown" > /run/initramfs/etc/cmdline.d/debug.conf
|
|
|
|
# touch /run/initramfs/.need_shutdown
|
|
|
|
----
|
|
|
|
|
|
|
|
This will give you a dracut shell after the system pivot'ed back in the
|
|
|
|
initramfs.
|
|
|
|
|