system/systemd
system/systemd
1
0
Fork 0
mirror of https://github.com/systemd/systemd synced 2024-07-21 10:17:21 +00:00
Code Issues Actions 9 Packages Projects Releases Wiki Activity

man: "the initial RAM disk" → "the initrd"

Browse source 
In many places we spelled out the phrase behind "initrd" in full, but this
isn't terribly useful. In fact, no "RAM disk" is used, so emphasizing this
is just confusing to the reader. Let's just say "initrd" everywhere, people
understand what this refers to, and that it's in fact an initramfs image.

Also, s/i.e./e.g./ where appropriate.

Also, don't say "in RAM", when in fact it's virtual memory, whose pages
may or may not be loaded in page frames in RAM, and we have no control over
this.

Also, add <filename></filename> and other minor cleanups.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2022-09-15 13:43:59 +01:00
parent 483bf5643a
commit b66a6e1a58
18 changed files with 143 additions and 158 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
man/bootctl.xml
View file

@ -319,11 +319,11 @@
<term><option>--make-entry-directory=yes|no</option></term>
<listitem><para>Controls creation and deletion of the <ulink
url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink> Type #1 entry
directory on the file system containing resources such as kernel images and initial RAM disk images
during <option>install</option> and <option>remove</option>, respectively. The directory is named
after the entry token, as specified with <option>--entry-token=</option> parameter described below,
and is placed immediately below the <varname>$BOOT</varname> root directory (i.e. beneath the file
system returned by the <option>--print-boot-path</option> option, see above). Defaults to
directory on the file system containing resources such as kernel and initrd images during
<option>install</option> and <option>remove</option>, respectively. The directory is named after the
entry token, as specified with <option>--entry-token=</option> parameter described below, and is
placed immediately below the <varname>$BOOT</varname> root directory (i.e. beneath the file system
returned by the <option>--print-boot-path</option> option, see above). Defaults to
<literal>no</literal>.</para></listitem>
</varlistentry>

14
man/bootup.xml
View file

@ -33,13 +33,13 @@
<para>The kernel (optionally) mounts an in-memory file system, often generated by
<citerefentry project='man-pages'><refentrytitle>dracut</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
which looks for the root file system. Nowadays this is usually implemented as an initramfs — a compressed
archive which is extracted when the kernel boots up into a lightweight in-memory file system based on
tmpfs, but in the past normal file systems using an in-memory block device (ramdisk) were used, and the
name "initrd" is still used to describe both concepts. It's the boot loader or the firmware that loads
both the kernel and initrd/initramfs images into memory, but the kernel which interprets it as a file
system. <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> may
be used to manage services in the initrd, similarly to the real system.</para>
which looks for the root file system. Nowadays this is implemented as an "initramfs" — a compressed CPIO
archive that the kernel extracts into a tmpfs. In the past normal file systems using an in-memory block
device (ramdisk) were used, and the name "initrd" is still used to describe both concepts. It's the boot
loader or the firmware that loads both the kernel and initrd/initramfs images into memory, but the kernel
which interprets it as a file system.
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> may be used
to manage services in the initrd, similarly to the real system.</para>
<para>After the root file system is found and mounted, the initrd hands over control to the host's system
manager (such as

7
man/kernel-command-line.xml
View file

@ -27,8 +27,8 @@
<refsect1>
<title>Description</title>
<para>The kernel, the initial RAM disk (initrd) and basic userspace functionality may be configured at
boot via kernel command line arguments. In addition, various systemd tools look at the EFI variable
<para>The kernel, the programs running in the initrd and in the host system may be configured at boot via
kernel command line arguments. In addition, various systemd tools look at the EFI variable
<literal>SystemdOptions</literal> (if available). Both sources are combined, but the kernel command line
has higher priority. Please note that <emphasis>the EFI variable is only used by systemd tools, and is
ignored by the kernel and other user space tools</emphasis>, so it is not a replacement for the kernel
@ -40,8 +40,7 @@
and
<citerefentry project='man-pages'><refentrytitle>bootparam</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
<para>For command line parameters understood by the initial RAM
disk, please see
<para>For command line parameters understood by the initrd, see
<citerefentry project='man-pages'><refentrytitle>dracut.cmdline</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
or the documentation of the specific initrd implementation of your
installation.</para>

25
man/kernel-install.xml
View file

@ -18,7 +18,7 @@
<refnamediv>
<refname>kernel-install</refname>
<refpurpose>Add and remove kernel and initramfs images to and from /boot</refpurpose>
<refpurpose>Add and remove kernel and initrd images to and from /boot</refpurpose>
</refnamediv>
<refsynopsisdiv>
@ -34,10 +34,15 @@
<refsect1>
<title>Description</title>
<para><command>kernel-install</command> is used to install and remove kernel and initramfs images to and
from the boot loader partition, referred to as <varname>$BOOT</varname> here. It will usually be one of
<filename>/boot/</filename>, <filename>/efi/</filename>, or <filename>/boot/efi/</filename>, see below.
</para>
<para><command>kernel-install</command> is used to install and remove kernel and initrd images
<footnote>
<para>Nowadays actually CPIO archives used as an "initramfs", rather than "initrd". See
<citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry> for an
explanation.</para>
</footnote>
to and from the boot loader partition, referred to as <varname>$BOOT</varname> here. It will usually be
one of <filename>/boot/</filename>, <filename>/efi/</filename>, or <filename>/boot/efi/</filename>, see
below.</para>
<para><command>kernel-install</command> will run the executable files ("plugins") located in the
directory <filename>/usr/lib/kernel/install.d/</filename> and the local administration directory
@ -63,16 +68,16 @@
<varlistentry>
<term><command>add <replaceable>KERNEL-VERSION</replaceable> <replaceable>KERNEL-IMAGE</replaceable> [<replaceable>INITRD-FILE</replaceable> ...]</command></term>
<listitem>
<para>This command expects a kernel version string and a path to a kernel image file as
arguments. Optionally, one or more initial RAM disk images may be specified as well (note that
plugins might generate additional ones). <command>kernel-install</command> calls the executable
files from <filename>/usr/lib/kernel/install.d/*.install</filename> and
<para>This command expects a kernel version string and a path to a kernel image file as arguments.
Optionally, one or more initrd images may be specified as well (note that plugins might generate
additional ones). <command>kernel-install</command> calls the executable files from
<filename>/usr/lib/kernel/install.d/*.install</filename> and
<filename>/etc/kernel/install.d/*.install</filename> (i.e. the plugins) with the following
arguments:</para>
<programlisting>add <replaceable>KERNEL-VERSION</replaceable> <filename>$BOOT/<replaceable>ENTRY-TOKEN</replaceable>/<replaceable>KERNEL-VERSION</replaceable>/</filename> <replaceable>KERNEL-IMAGE</replaceable> [<replaceable>INITRD-FILE</replaceable> ...]</programlisting>
<para>The third argument directly refers to the path where to place kernel images, initial RAM disk
<para>The third argument directly refers to the path where to place kernel images, initrd
images and other resources for <ulink url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot
Loader Specification</ulink> Type #1 entries (the "entry directory"). If other boot loader schemes
are used the parameter may be ignored. The <replaceable>ENTRY-TOKEN</replaceable> string is

10
man/org.freedesktop.systemd1.xml
View file

@ -1368,11 +1368,11 @@ node /org/freedesktop/systemd1 {
for more information.</para>
<para><function>SwitchRoot()</function> may be used to transition to a new root directory. This is
intended to be used by initial RAM disks. The method takes two arguments: the new root directory (which
needs to be specified) and an init binary path (which may be left empty, in which case it is
automatically searched for). The state of the system manager will be serialized before the
transition. After the transition, the manager binary on the main system is invoked and replaces the old
PID 1. All state will then be deserialized.</para>
intended to be used in the initrd, and also to transition from the host system into a shutdown initrd.
The method takes two arguments: the new root directory (which needs to be specified) and an init binary
path (which may be left empty, in which case it is automatically searched for). The state of the system
manager will be serialized before the transition. After the transition, the manager binary on the main
system is invoked and replaces the old PID 1. All state will then be deserialized.</para>
<para><function>SetEnvironment()</function> may be used to alter the environment block that is passed
to all spawned processes. It takes a string array of environment variable assignments. Any previously set

9
man/os-release.xml
View file

@ -442,11 +442,10 @@
<listitem><para>Takes a space-separated list of one or more of the strings
<literal>system</literal>, <literal>initrd</literal> and <literal>portable</literal>. This field is
only supported in <filename>extension-release.d/</filename> files and indicates what environments
the system extension is applicable to: i.e. to regular systems, to initial RAM filesystems
("initrd") or to portable service images. If unspecified, <literal>SYSEXT_SCOPE=system
portable</literal> is implied, i.e. any system extension without this field is applicable to
regular systems and to portable service environments, but not to initrd
environments.</para></listitem>
the system extension is applicable to: i.e. to regular systems, to initrds, or to portable service
images. If unspecified, <literal>SYSEXT_SCOPE=system portable</literal> is implied, i.e. any system
extension without this field is applicable to regular systems and to portable service environments,
but not to initrd environments.</para></listitem>
</varlistentry>
<varlistentry>

19
man/systemctl.xml
View file

@ -1527,15 +1527,16 @@ Jan 12 10:46:45 example.com bluetoothd[8900]: gatt-time-server: Input/output err
<term><command>switch-root</command> <replaceable>ROOT</replaceable> <optional><replaceable>INIT</replaceable></optional></term>
<listitem>
<para>Switches to a different root directory and executes a new system manager process below it. This is
intended for usage in initial RAM disks ("initrd"), and will transition from the initrd's system manager
process (a.k.a. "init" process) to the main system manager process which is loaded from the actual host
volume. This call takes two arguments: the directory that is to become the new root directory, and the path
to the new system manager binary below it to execute as PID 1. If the latter is omitted or the empty
string, a systemd binary will automatically be searched for and used as init. If the system manager path is
omitted, equal to the empty string or identical to the path to the systemd binary, the state of the
initrd's system manager process is passed to the main system manager, which allows later introspection of
the state of the services involved in the initrd boot phase.</para>
<para>Switches to a different root directory and executes a new system manager process below it.
This is intended for use in the initrd, and will transition from the initrd's system manager
process (a.k.a. "init" process) to the main system manager process which is loaded from the
actual host root files system. This call takes two arguments: the directory that is to become the
new root directory, and the path to the new system manager binary below it to execute as PID 1.
If the latter is omitted or the empty string, a systemd binary will automatically be searched for
and used as init. If the system manager path is omitted, equal to the empty string or identical
to the path to the systemd binary, the state of the initrd's system manager process is passed to
the main system manager, which allows later introspection of the state of the services involved
in the initrd boot phase.</para>
</listitem>
</varlistentry>

2
man/systemd-boot.xml
View file

@ -444,7 +444,7 @@
stored in the EFI variable <varname>LoaderSystemToken</varname> (see below). During early OS boot the
system manager reads this variable and passes it to the OS kernel's random pool, crediting the full
entropy it contains. This is an efficient way to ensure the system starts up with a fully initialized
kernel random pool — as early as the initial RAM disk phase. <command>systemd-boot</command> reads
kernel random pool — as early as the initrd phase. <command>systemd-boot</command> reads
the random seed from the ESP, combines it with the "system token", and both derives a new random seed
to update in-place the seed stored in the ESP, and the random seed to pass to the OS from it via
SHA256 hashing in counter mode. This ensures that different physical systems that boot the same

9
man/systemd-creds.xml
View file

@ -129,11 +129,10 @@
</orderedlist>
<para>Which of the three keys shall be used for encryption may be configured with the
<option>--with-key=</option> switch. Depending on the use-case for the encrypted credential the key to
use may differ. For example, for credentials that shall be accessible from the initial RAM disk
(initrd) of the system encryption with the host key is not appropriate since access to the host key
is typically not available from the initrd. Thus, for such credentials only the TPM2 key should be
used.</para>
<option>--with-key=</option> switch. Depending on the use-case for the encrypted credential the key
to use may differ. For example, for credentials that shall be accessible from the initrd, encryption
with the host key is not appropriate, since access to the host key is typically not available from
the initrd. Thus, for such credentials only the TPM2 key should be used.</para>
<para>Encrypted credentials are always encoded in Base64.</para>

4
man/systemd-cryptenroll.xml
View file

@ -296,7 +296,7 @@
<row>
<entry>9</entry>
<entry>The Linux kernel measures all initial RAM file systems it receives into this PCR.</entry>
<entry>The Linux kernel measures all initrds it receives into this PCR.</entry>
<!-- Strictly speaking only Linux >= 5.17 using the LOAD_FILE2 protocol, see https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f046fff8bc4c4d8f8a478022e76e40b818f692df -->
</row>
@ -307,7 +307,7 @@
<row>
<entry>11</entry>
<entry><citerefentry><refentrytitle>systemd-stub</refentrytitle><manvolnum>7</manvolnum></citerefentry> measures the ELF kernel image, embedded initrd and other payload of the PE image it is placed in into this PCR. Unlike PCR 4 (where the same data should be measured into), this PCR value should be easy to pre-calculate, as this only contains static parts of the PE binary. Use this PCR to bind TPM policies to a specific kernel image, possibly with an embedded initial RAM disk (initrd).</entry>
<entry><citerefentry><refentrytitle>systemd-stub</refentrytitle><manvolnum>7</manvolnum></citerefentry> measures the ELF kernel image, embedded initrd and other payload of the PE image it is placed in into this PCR. Unlike PCR 4 (where the same data should be measured into), this PCR value should be easy to pre-calculate, as this only contains static parts of the PE binary. Use this PCR to bind TPM policies to a specific kernel image, possibly with an embedded initrd.</entry>
</row>
<row>

67
man/systemd-cryptsetup-generator.xml
View file

@ -49,48 +49,40 @@
<term><varname>luks=</varname></term>
<term><varname>rd.luks=</varname></term>
<listitem><para>Takes a boolean argument. Defaults to
<literal>yes</literal>. If <literal>no</literal>, disables the
generator entirely. <varname>rd.luks=</varname> is honored
only by initial RAM disk (initrd) while
<varname>luks=</varname> is honored by both the main system
and the initrd. </para></listitem>
<listitem><para>Takes a boolean argument. Defaults to <literal>yes</literal>. If
<literal>no</literal>, disables the generator entirely. <varname>rd.luks=</varname> is honored only
in the initrd while <varname>luks=</varname> is honored by both the main system and in the initrd.
</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>luks.crypttab=</varname></term>
<term><varname>rd.luks.crypttab=</varname></term>
<listitem><para>Takes a boolean argument. Defaults to
<literal>yes</literal>. If <literal>no</literal>, causes the
generator to ignore any devices configured in
<filename>/etc/crypttab</filename>
(<varname>luks.uuid=</varname> will still work however).
<varname>rd.luks.crypttab=</varname> is honored only by
initial RAM disk (initrd) while
<varname>luks.crypttab=</varname> is honored by both the main
system and the initrd. </para></listitem>
<listitem><para>Takes a boolean argument. Defaults to <literal>yes</literal>. If
<literal>no</literal>, causes the generator to ignore any devices configured in
<filename>/etc/crypttab</filename> (<varname>luks.uuid=</varname> will still work however).
<varname>rd.luks.crypttab=</varname> is honored only in initrd while
<varname>luks.crypttab=</varname> is honored by both the main system and the initrd.
</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>luks.uuid=</varname></term>
<term><varname>rd.luks.uuid=</varname></term>
<listitem><para>Takes a LUKS superblock UUID as argument. This
will activate the specified device as part of the boot process
as if it was listed in <filename>/etc/crypttab</filename>.
This option may be specified more than once in order to set up
multiple devices. <varname>rd.luks.uuid=</varname> is honored
only by initial RAM disk (initrd) while
<varname>luks.uuid=</varname> is honored by both the main
system and the initrd.</para>
<para>If /etc/crypttab contains entries with the same UUID,
then the name, keyfile and options specified there will be
used. Otherwise, the device will have the name
<listitem><para>Takes a LUKS superblock UUID as argument. This will activate the specified device as
part of the boot process as if it was listed in <filename>/etc/crypttab</filename>. This option may
be specified more than once in order to set up multiple devices. <varname>rd.luks.uuid=</varname> is
honored only in the initrd, while <varname>luks.uuid=</varname> is honored by both the main system
and the initrd.</para>
<para>If <filename>/etc/crypttab</filename> contains entries with the same UUID, then the name,
keyfile and options specified there will be used. Otherwise, the device will have the name
<literal>luks-UUID</literal>.</para>
<para>If /etc/crypttab exists, only those UUIDs
specified on the kernel command line
will be activated in the initrd or the real root.</para>
<para>If <filename>/etc/crypttab</filename> exists, only those UUIDs specified on the kernel command
line will be activated in the initrd or the real root.</para>
</listitem>
</varlistentry>
@ -108,9 +100,8 @@
<para>This parameter is the analogue of the first <citerefentry><refentrytitle>crypttab</refentrytitle>
<manvolnum>5</manvolnum></citerefentry> field <replaceable>volume-name</replaceable>.</para>
<para><varname>rd.luks.name=</varname> is honored only by
initial RAM disk (initrd) while <varname>luks.name=</varname>
is honored by both the main system and the initrd.</para>
<para><varname>rd.luks.name=</varname> is honored only in the initrd, while
<varname>luks.name=</varname> is honored by both the main system and the initrd.</para>
</listitem>
</varlistentry>
@ -137,8 +128,8 @@
<para>This parameter is the analogue of the second <citerefentry><refentrytitle>crypttab</refentrytitle>
<manvolnum>5</manvolnum></citerefentry> field <replaceable>encrypted-device</replaceable>.</para>
<para><varname>rd.luks.data=</varname> is honored only by initial RAM disk (initrd) while
<varname>luks.data=</varname> is honored by both the main system and the initrd.</para>
<para><varname>rd.luks.data=</varname> is honored only in the initrd, while
<varname>luks.data=</varname> is honored by both the main system and in the initrd.</para>
</listitem>
</varlistentry>
@ -173,12 +164,8 @@
<para>This parameter is the analogue of the third <citerefentry><refentrytitle>crypttab</refentrytitle>
<manvolnum>5</manvolnum></citerefentry> field <replaceable>key-file</replaceable>.</para>
<para><varname>rd.luks.key=</varname>
is honored only by initial RAM disk
(initrd) while
<varname>luks.key=</varname> is
honored by both the main system and
the initrd.</para>
<para><varname>rd.luks.key=</varname> is honored only in the initrd, while
<varname>luks.key=</varname> is honored by both the main system and in the initrd.</para>
</listitem>
</varlistentry>

23
man/systemd-fstab-generator.xml
View file

@ -70,13 +70,10 @@
<term><varname>fstab=</varname></term>
<term><varname>rd.fstab=</varname></term>
<listitem><para>Takes a boolean argument. Defaults to
<literal>yes</literal>. If <literal>no</literal>, causes the
generator to ignore any mounts or swap devices configured in
<filename>/etc/fstab</filename>. <varname>rd.fstab=</varname>
is honored only by the initial RAM disk (initrd) while
<varname>fstab=</varname> is honored by both the main system
and the initrd.</para></listitem>
<listitem><para>Takes a boolean argument. Defaults to <literal>yes</literal>. If
<literal>no</literal>, causes the generator to ignore any mounts or swap devices configured in
<filename>/etc/fstab</filename>. <varname>rd.fstab=</varname> is honored only in the initrd, while
<varname>fstab=</varname> is honored by both the main system and the initrd.</para></listitem>
</varlistentry>
<varlistentry>
@ -194,12 +191,12 @@
<para>If true the generator ensures
<citerefentry><refentrytitle>systemd-volatile-root.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
is run as part of the initial RAM disk ("initrd"). This service changes the mount table before transitioning to
the host system, so that a volatile memory file system (<literal>tmpfs</literal>) is used as root directory,
with only <filename>/usr/</filename> mounted into it from the configured root file system, in read-only
mode. This way the system operates in fully stateless mode, with all configuration and state reset at boot and
lost at shutdown, as <filename>/etc/</filename> and <filename>/var/</filename> will be served from the (initially
unpopulated) volatile memory file system.</para>
is run in the initrd. This service changes the mount table before transitioning to the host system,
so that a volatile memory file system (<literal>tmpfs</literal>) is used as root directory, with only
<filename>/usr/</filename> mounted into it from the configured root file system, in read-only mode.
This way the system operates in fully stateless mode, with all configuration and state reset at boot
and lost at shutdown, as <filename>/etc/</filename> and <filename>/var/</filename> will be served
from the (initially unpopulated) volatile memory file system.</para>
<para>If set to <option>state</option> the generator will leave the root directory mount point unaltered,
however will mount a <literal>tmpfs</literal> file system to <filename>/var/</filename>. In this mode the normal

6
man/systemd-modules-load.service.xml
View file

@ -52,10 +52,8 @@
<term><varname>modules_load=</varname></term>
<term><varname>rd.modules_load=</varname></term>
<listitem><para>Takes a comma-separated list of kernel modules
to statically load during early boot. The option prefixed with
<literal>rd.</literal> is read by the initial RAM disk
only.</para></listitem>
<listitem><para>Takes a comma-separated list of kernel modules to statically load during early boot.
The option prefixed with <literal>rd.</literal> is read in the initrd only.</para></listitem>
</varlistentry>
</variablelist>

6
man/systemd-nspawn.xml
View file

@ -443,9 +443,9 @@
in the container's file system namespace.</para>
<para>This is for containers which have several bootable directories in them; for example, several
<ulink url="https://ostree.readthedocs.io/en/latest/">OSTree</ulink> deployments. It emulates the behavior of
the boot loader and initial RAM disk which normally select which directory to mount as the root and start the
container's PID 1 in.</para></listitem>
<ulink url="https://ostree.readthedocs.io/en/latest/">OSTree</ulink> deployments. It emulates the
behavior of the boot loader and the initrd which normally select which directory to mount as the root
and start the container's PID 1 in.</para></listitem>
</varlistentry>
</variablelist>

10
man/systemd-random-seed.service.xml
View file

@ -33,14 +33,14 @@
into the kernel entropy pool during boot and saves it at shutdown. See
<citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry> for
details. By default, no entropy is credited when the random seed is written into the kernel entropy pool,
but this may be changed with <varname>$SYSTEMD_RANDOM_SEED_CREDIT</varname>, see below. On disk the random
but this may be changed with <varname>$SYSTEMD_RANDOM_SEED_CREDIT</varname>, see below. On disk the random
seed is stored in <filename>/var/lib/systemd/random-seed</filename>.</para>
<para>Note that this service runs relatively late during the early boot phase, i.e. generally after the
initial RAM disk (initrd) completed its work, and the <filename>/var/</filename> file system has been
mounted writable. Many system services require entropy much earlier than this — this service is hence of
limited use for complex system. It is recommended to use a boot loader that can pass an initial random
seed to the kernel to ensure that entropy is available from earliest boot on, for example
initrd phase has finished and the <filename>/var/</filename> file system has been mounted. Many system
services require entropy much earlier than this — this service is hence of limited use for complex
system. It is recommended to use a boot loader that can pass an initial random seed to the kernel to
ensure that entropy is available from earliest boot on, for example
<citerefentry><refentrytitle>systemd-boot</refentrytitle><manvolnum>7</manvolnum></citerefentry>, with
its <command>bootctl random-seed</command> functionality.</para>

2
man/systemd-remount-fs.service.xml
View file

@ -36,7 +36,7 @@
<citerefentry><refentrytitle>systemd-gpt-auto-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
is active) to the root file system, the <filename>/usr/</filename> file system, and the kernel API file
systems. This is required so that the mount options of these file systems — which are pre-mounted by the
kernel, the initial RAM disk, container environments or system manager code — are updated to those
kernel, the initrd, container environments or system manager code — are updated to those
configured in <filename>/etc/fstab</filename> and the other sources. This service ignores normal file
systems and only changes the root file system (i.e. <filename>/</filename>), <filename>/usr/</filename>,
and the virtual kernel API file systems such as <filename>/proc/</filename>, <filename>/sys/</filename> or

56
man/systemd-repart.xml
View file

@ -43,14 +43,14 @@
<para>If invoked with no arguments, it operates on the block device backing the root file system
partition of the running OS, thus growing and adding partitions of the booted OS image itself. If
<varname>--image=</varname> is used it will operate on the specified image file. When called in the
<literal>initrd</literal> it operates on the block device backing <filename>/sysroot/</filename> instead,
i.e. on the block device the system will soon transition into. The
<filename>systemd-repart.service</filename> service is generally run at boot in the initial RAM disk, in
order to augment the partition table of the OS before its partitions are
mounted. <command>systemd-repart</command> (mostly) operates in a purely incremental mode: it only grows
existing and adds new partitions; it does not shrink, delete or move existing partitions. The service is
intended to be run on every boot, but when it detects that the partition table already matches the
installed <filename>repart.d/*.conf</filename> configuration files, it executes no operation.</para>
initrd it operates on the block device backing <filename>/sysroot/</filename> instead, i.e. on the block
device the system will soon transition into. The <filename>systemd-repart.service</filename> service is
generally run at boot in the initrd, in order to augment the partition table of the OS before its
partitions are mounted. <command>systemd-repart</command> (mostly) operates in a purely incremental mode:
it only grows existing and adds new partitions; it does not shrink, delete or move existing partitions.
The service is intended to be run on every boot, but when it detects that the partition table already
matches the installed <filename>repart.d/*.conf</filename> configuration files, it executes no
operation.</para>
<para><command>systemd-repart</command> is intended to be used when deploying OS images, to automatically
adjust them to the system they are running on, during first boot. This way the deployed image can be
@ -89,34 +89,34 @@
<listitem><para>Taking the size constraints and weights declared in the configuration files into
account, all partitions that shall be created are now allocated to the disk, taking up all free space,
always respecting the size and padding requests. Similar, existing partitions that are determined to
grow are grown. New partitions are always appended to the end of the existing partition table, taking
the first partition table slot whose index is greater than the indexes of all existing
partitions. Partition table slots are never reordered and thus partition numbers are ensured to remain
stable. Note that this allocation happens in RAM only, the partition table on disk is not updated
yet.</para></listitem>
always respecting the size and padding requests. Similarly, existing partitions that should be grown
are grown. New partitions are always appended to the end of the partition table, taking the first
partition table slot whose index is greater than the indexes of all existing partitions. Partition
table slots are never reordered and thus partition numbers are ensured to remain stable. Note that this
allocation happens in memory only, the partition table on disk is not updated yet.</para></listitem>
<listitem><para>All existing partitions for which configuration files exist and which currently have no
GPT partition label set will be assigned a label, either explicitly configured in the configuration or
(if that's missing) derived automatically from the partition type. The same is done for all partitions
that are newly created. These assignments are done in RAM only, too, the disk is not updated
yet.</para></listitem>
— if that's missing — derived automatically from the partition type. The same is done for all
partitions that are newly created. These assignments are done in memory only, too, the disk is not
updated yet.</para></listitem>
<listitem><para>Similarly, all existing partitions for which configuration files exist and which
currently have an all-zero identifying UUID will be assigned a new UUID. This UUID is cryptographically
hashed from a common seed value together with the partition type UUID (and a counter in case multiple
partitions of the same type are defined), see below. The same is done for all partitions that are
created anew. These assignments are done in RAM only, too, the disk is not updated
yet.</para></listitem>
created anew. These assignments are done in memory only, too, the disk is not updated yet.
</para></listitem>
<listitem><para>Similarly, if the disk's volume UUID is all zeroes it is also initialized, also
cryptographically hashed from the same common seed value. Also, in RAM only, too.</para></listitem>
cryptographically hashed from the same common seed value. This is done in memory only too.
</para></listitem>
<listitem><para>The disk space assigned to new partitions (i.e. what was previously considered free
space but is no longer) is now erased. Specifically, all file system signatures are removed, and if the
device supports it the <constant>BLKDISCARD</constant> I/O control command is issued to inform the
hardware that the space is empty now. In addition any "padding" between partitions and at the end of
the device is similarly erased.</para></listitem>
<listitem><para>The disk space assigned to new partitions (i.e. what was previously free space) is now
erased. Specifically, all file system signatures are removed, and if the device supports it, the
<constant>BLKDISCARD</constant> I/O control command is issued to inform the hardware that the space is
now empty. In addition any "padding" between partitions and at the end of the device is similarly
erased.</para></listitem>
<listitem><para>The new partition table is finally written to disk. The kernel is asked to reread the
partition table.</para></listitem>
@ -257,9 +257,9 @@
<filename>repart.d/*.conf</filename> files, for the machine ID file to use as seed and for the
<varname>CopyFiles=</varname> and <varname>CopyBlocks=</varname> source files and directories. By
default when invoked on the regular system this defaults to the host's root file system
<filename>/</filename>. If invoked from the initial RAM disk this defaults to
<filename>/sysroot/</filename>, so that the tool operates on the configuration and machine ID stored
in the root file system later transitioned into itself.</para></listitem>
<filename>/</filename>. If invoked from the initrd this defaults to <filename>/sysroot/</filename>,
so that the tool operates on the configuration and machine ID stored in the root file system later
transitioned into itself.</para></listitem>
</varlistentry>
<varlistentry>

22
man/systemd-stub.xml
View file

@ -57,8 +57,8 @@
<citerefentry><refentrytitle>os-release</refentrytitle><manvolnum>5</manvolnum></citerefentry> file of
the OS the kernel belongs to, in the <literal>.osrel</literal> PE section.</para></listitem>
<listitem><para>The initial RAM disk (initrd) will be looked for in the <literal>.initrd</literal> PE
section.</para></listitem>
<listitem><para>The initrd will be loaded from the <literal>.initrd</literal> PE section.
</para></listitem>
<listitem><para>A compiled binary DeviceTree will be looked for in the <literal>.dtb</literal> PE
section.</para></listitem>
@ -290,27 +290,27 @@
<varlistentry>
<term><varname>StubPcrKernelImage</varname></term>
<listitem><para>The PCR register index the ELF kernel image/initial RAM disk image/boot
splash/devicetree database/embedded command line are measured into, formatted as decimal ASCII string
(i.e. <literal>11</literal>). This variable is set if a measurement was successfully completed, and
remains unset otherwise.</para></listitem>
<listitem><para>The PCR register index the kernel image, initrd image, boot splash, devicetree
database, and the embedded command line are measured into, formatted as decimal ASCII string (e.g.
<literal>11</literal>). This variable is set if a measurement was successfully completed, and remains
unset otherwise.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>StubPcrKernelParameters</varname></term>
<listitem><para>The PCR register index the kernel command line and credentials are measured into,
formatted as decimal ASCII string (i.e. <literal>12</literal>). This variable is set if a measurement
formatted as decimal ASCII string (e.g. <literal>12</literal>). This variable is set if a measurement
was successfully completed, and remains unset otherwise.</para></listitem>
</varlistentry>
<varlistentry>
<term><varname>StubPcrInitRDSysExts</varname></term>
<listitem><para>The PCR register index the systemd extensions for the initial RAM disk image, which
are picked up from the file system the kernel image is located on. Formatted as decimal ASCII string
(i.e. <literal>13</literal>). This variable is set if a measurement was successfully completed, and
remains unset otherwise.</para></listitem>
<listitem><para>The PCR register index the systemd extensions for the initrd, which are picked up
from the file system the kernel image is located on. Formatted as decimal ASCII string (e.g.
<literal>13</literal>). This variable is set if a measurement was successfully completed, and remains
unset otherwise.</para></listitem>
</varlistentry>
</variablelist>