man/systemd-repart.xml - systemd - Git at Google

 <?xml version='1.0'?> <!--*-nxml-*-->
 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
 <!-- SPDX-License-Identifier: LGPL-2.1-or-later -->

 <refentry id="systemd-repart" conditional='ENABLE_REPART'
     xmlns:xi="http://www.w3.org/2001/XInclude">

   <refentryinfo>
     <title>systemd-repart</title>
     <productname>systemd</productname>
   </refentryinfo>

   <refmeta>
     <refentrytitle>systemd-repart</refentrytitle>
     <manvolnum>8</manvolnum>
   </refmeta>

   <refnamediv>
     <refname>systemd-repart</refname>
     <refname>systemd-repart.service</refname>
     <refpurpose>Automatically grow and add partitions</refpurpose>
   </refnamediv>

   <refsynopsisdiv>
     <cmdsynopsis>
       <command>systemd-repart</command>
       <arg choice="opt" rep="repeat">OPTIONS</arg>
       <arg choice="opt" rep="repeat"><replaceable><optional>BLOCKDEVICE</optional></replaceable></arg>
     </cmdsynopsis>

     <para><filename>systemd-repart.service</filename></para>
   </refsynopsisdiv>

   <refsect1>
     <title>Description</title>

     <para><command>systemd-repart</command> grows and adds partitions to a partition table, based on the
     configuration files described in
     <citerefentry><refentrytitle>repart.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
     </para>

     <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>

     <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
     minimal in size and may be augmented automatically at boot when needed, taking possession of disk space
     available but not yet used. Specifically the following use cases are among those covered:</para>

     <itemizedlist>
       <listitem><para>The root partition may be grown to cover the whole available disk space.</para></listitem>
       <listitem><para>A <filename>/home/</filename>, swap or <filename>/srv/</filename> partition can be
       added.</para></listitem>
       <listitem><para>A second (or third, …) root partition may be added, to cover A/B style setups
       where a second version of the root file system is alternatingly used for implementing update
       schemes. The deployed image would carry only a single partition ("A") but on first boot a second
       partition ("B") for this purpose is automatically created.</para></listitem>
     </itemizedlist>

     <para>The algorithm executed by <command>systemd-repart</command> is roughly as follows:</para>

     <orderedlist>
       <listitem><para>The <filename>repart.d/*.conf</filename> configuration files are loaded and parsed,
       and ordered by filename (without the directory prefix).</para></listitem>

       <listitem><para>The partition table already existing on the block device is loaded and
       parsed.</para></listitem>

       <listitem><para>The existing partitions in the partition table are matched up with the
       <filename>repart.d/*.conf</filename> files by GPT partition type UUID. The first existing partition
       of a specific type is assigned the first configuration file declaring the same type. The second
       existing partition of a specific type is then assigned the second configuration file declaring the same
       type, and so on. After this iterative assigning is complete any left-over existing partitions that have
       no matching configuration file are considered "foreign" and left as they are. And any configuration
       files for which no partition currently exists are understood as a request to create such a
       partition.</para></listitem>

       <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>

       <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>

       <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>

       <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>

       <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 new partition table is finally written to disk. The kernel is asked to reread the
       partition table.</para></listitem>
     </orderedlist>

     <para>As exception to the normally strictly incremental operation, when called in a special "factory
     reset" mode, <command>systemd-repart</command> may also be used to erase existing partitions to
     reset an installation back to vendor defaults. This mode of operation is used when either the
     <option>--factory-reset=yes</option> switch is passed on the tool's command line, or the
     <option>systemd.factory_reset=yes</option> option specified on the kernel command line, or the
     <varname>FactoryReset</varname> EFI variable (vendor UUID
     <constant>8cf2644b-4b0b-428f-9387-6d876050dc67</constant>) is set to "yes". It alters the algorithm above
     slightly: between the 3rd and the 4th step above any partition marked explicitly via the
     <varname>FactoryReset=</varname> boolean is deleted, and the algorithm restarted, thus immediately
     re-creating these partitions anew empty.</para>

     <para>Note that <command>systemd-repart</command> only changes partition tables, it does not create or
     resize any file systems within these partitions. A separate mechanism should be used for that, for
     example
     <citerefentry><refentrytitle>systemd-growfs</refentrytitle><manvolnum>8</manvolnum></citerefentry> and
     <command>systemd-makefs</command>.</para>

     <para>The UUIDs identifying the new partitions created (or assigned to existing partitions that have no
     UUID yet), as well as the disk as a whole are hashed cryptographically from a common seed value. This
     seed value is usually the
     <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> of the
     system, so that the machine ID reproducibly determines the UUIDs assigned to all partitions. If the
     machine ID cannot be read (or the user passes <option>--seed=random</option>, see below) the seed is
     generated randomly instead, so that the partition UUIDs are also effectively random. The seed value may
     also be set explicitly, formatted as UUID via the <option>--seed=</option> option. By hashing these UUIDs
     from a common seed images prepared with this tool become reproducible and the result of the algorithm
     above deterministic.</para>

     <para>The positional argument should specify the block device to operate on. Instead of a block device
     node path a regular file may be specified too, in which case the command operates on it like it would if
     a loopback block device node was specified with the file attached. If <option>--empty=create</option> is
     specified the specified path is created as regular file, which is useful for generating disk images from
     scratch.</para>
   </refsect1>

   <refsect1>
     <title>Options</title>

     <para>The following options are understood:</para>

     <variablelist>
       <varlistentry>
         <term><option>--dry-run=</option></term>
         <listitem><para>Takes a boolean. If this switch is not specified <option>--dry-run=yes</option> is
         the implied default. Controls whether <filename>systemd-repart</filename> executes the requested
         re-partition operations or whether it should only show what it would do. Unless
         <option>--dry-run=no</option> is specified <filename>systemd-repart</filename> will not actually
         touch the device's partition table.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--empty=</option></term>
         <listitem><para>Takes one of <literal>refuse</literal>, <literal>allow</literal>,
         <literal>require</literal>, <literal>force</literal> or <literal>create</literal>. Controls how to
         operate on block devices that are entirely empty, i.e. carry no partition table/disk label yet. If
         this switch is not specified the implied default is <literal>refuse</literal>.</para>

         <para>If <literal>refuse</literal> <command>systemd-repart</command> requires that the block device
         it shall operate on already carries a partition table and refuses operation if none is found. If
         <literal>allow</literal> the command will extend an existing partition table or create a new one if
         none exists. If <literal>require</literal> the command will create a new partition table if none
         exists so far, and refuse operation if one already exists. If <literal>force</literal> it will create
         a fresh partition table unconditionally, erasing the disk fully in effect. If
         <literal>force</literal> no existing partitions will be taken into account or survive the
         operation. Hence: use with care, this is a great way to lose all your data. If
         <literal>create</literal> a new loopback file is create under the path passed via the device node
         parameter, of the size indicated with <option>--size=</option>, see below.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--discard=</option></term>

         <listitem><para>Takes a boolean. If this switch is not specified <option>--discard=yes</option> is
         the implied default. Controls whether to issue the <constant>BLKDISCARD</constant> I/O control
         command on the space taken up by any added partitions or on the space in between them. Usually, it's
         a good idea to issue this request since it tells the underlying hardware that the covered blocks
         shall be considered empty, improving performance. If operating on a regular file instead of a block
         device node, a sparse file is generated.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--size=</option></term>

         <listitem><para>Takes a size in bytes, using the usual K, M, G, T suffixes, or the special value
         <literal>auto</literal>. If used the specified device node path must refer to a regular file, which
         is then grown to the specified size if smaller, before any change is made to the partition table. If
         specified as <literal>auto</literal> the minimal size for the disk image is automatically determined
         (i.e. the minimal sizes of all partitions are summed up, taking space for additional metadata into
         account). This switch is not supported if the specified node is a block device. This switch has no
         effect if the file is already as large as the specified size or larger. The specified size is
         implicitly rounded up to multiples of 4096. When used with <option>--empty=create</option> this
         specifies the initial size of the loopback file to create.</para>

         <para>The <option>--size=auto</option> option takes the sizes of pre-existing partitions into
         account. However, it does not accommodate for partition tables that are not tightly packed: the
         configured partitions might still not fit into the backing device if empty space exists between
         pre-existing partitions (or before the first partition) that cannot be fully filled by partitions to
         grow or create.</para>

         <para>Also note that the automatic size determination does not take files or directories specified
         with <option>CopyFiles=</option> into account: operation might fail if the specified files or
         directories require more disk space then the configured per-partition minimal size
         limit.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--factory-reset=</option></term>

         <listitem><para>Takes boolean. If this switch is not specified <option>--factory=reset=no</option> is
         the implied default. Controls whether to operate in "factory reset" mode, see above. If set to true
         this will remove all existing partitions marked with <varname>FactoryReset=</varname> set to yes
         early while executing the re-partitioning algorithm. Use with care, this is a great way to lose all
         your data. Note that partition files need to explicitly turn <varname>FactoryReset=</varname> on, as
         the option defaults to off. If no partitions are marked for factory reset this switch has no
         effect. Note that there are two other methods to request factory reset operation: via the kernel
         command line and via an EFI variable, see above.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--can-factory-reset</option></term>

         <listitem><para>If this switch is specified the disk is not re-partitioned. Instead it is determined
         if any existing partitions are marked with <varname>FactoryReset=</varname>. If there are the tool
         will exit with exit status zero, otherwise non-zero. This switch may be used to quickly determine
         whether the running system supports a factory reset mechanism built on
         <command>systemd-repart</command>.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--root=</option></term>

         <listitem><para>Takes a path to a directory to use as root file system when searching for
         <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>
       </varlistentry>

       <varlistentry>
         <term><option>--image=</option></term>

         <listitem><para>Takes a path to a disk image file or device to mount and use in a similar fashion to
         <option>--root=</option>, see above.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--seed=</option></term>

         <listitem><para>Takes a UUID as argument or the special value <constant>random</constant>. If a UUID
         is specified the UUIDs to assign to partitions and the partition table itself are derived via
         cryptographic hashing from it. If not specified it is attempted to read the machine ID from the host
         (or more precisely, the root directory configured via <option>--root=</option>) and use it as seed
         instead, falling back to a randomized seed otherwise. Use <option>--seed=random</option> to force a
         randomized seed. Explicitly specifying the seed may be used to generated strictly reproducible
         partition tables.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--pretty=</option></term>

         <listitem><para>Takes a boolean argument. If this switch is not specified, it defaults to on when
         called from an interactive terminal and off otherwise. Controls whether to show a user friendly table
         and graphic illustrating the changes applied.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--definitions=</option></term>

         <listitem><para>Takes a file system path. If specified the <filename>*.conf</filename> files are read
         from the specified directory instead of searching in <filename>/usr/lib/repart.d/*.conf</filename>,
         <filename>/etc/repart.d/*.conf</filename>,
         <filename>/run/repart.d/*.conf</filename>.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--key-file=</option></term>

         <listitem><para>Takes a file system path. Configures the encryption key to use when setting up LUKS2
         volumes configured with the <varname>Encrypt=key-file</varname> setting in partition files. Should
         refer to a regular file containing the key, or an <constant>AF_UNIX</constant> stream socket in the
         file system. In the latter case a connection is made to it and the key read from it. If this switch
         is not specified the empty key (i.e. zero length key) is used. This behaviour is useful for setting
         up encrypted partitions during early first boot that receive their user-supplied password only in a
         later setup step.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><option>--tpm2-device=</option></term>
         <term><option>--tpm2-pcrs=</option></term>

         <listitem><para>Configures the TPM2 device and list of PCRs to use for LUKS2 volumes configured with
         the <varname>Encrypt=tpm2</varname> option. These options take the same parameters as the identically
         named options to
         <citerefentry><refentrytitle>systemd-cryptenroll</refentrytitle><manvolnum>1</manvolnum></citerefentry>
         and have the same effect on partitions where TPM2 enrollment is requested.</para></listitem>
       </varlistentry>

       <xi:include href="standard-options.xml" xpointer="help" />
       <xi:include href="standard-options.xml" xpointer="version" />
       <xi:include href="standard-options.xml" xpointer="no-pager" />
       <xi:include href="standard-options.xml" xpointer="no-legend" />
       <xi:include href="standard-options.xml" xpointer="json" />
     </variablelist>
   </refsect1>

   <refsect1>
     <title>Exit status</title>

     <para>On success, 0 is returned, a non-zero failure code otherwise.</para>
   </refsect1>

   <refsect1>
     <title>See Also</title>
     <para>
       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>repart.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd-cryptenroll</refentrytitle><manvolnum>1</manvolnum></citerefentry>
     </para>
   </refsect1>

 </refentry>
	<?xml version='1.0'?> <!---nxml--->
	<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
	"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
	<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->

	<refentry id="systemd-repart" conditional='ENABLE_REPART'
	xmlns:xi="http://www.w3.org/2001/XInclude">

	<refentryinfo>
	<title>systemd-repart</title>
	<productname>systemd</productname>
	</refentryinfo>

	<refmeta>
	<refentrytitle>systemd-repart</refentrytitle>
	<manvolnum>8</manvolnum>
	</refmeta>

	<refnamediv>
	<refname>systemd-repart</refname>
	<refname>systemd-repart.service</refname>
	<refpurpose>Automatically grow and add partitions</refpurpose>
	</refnamediv>

	<refsynopsisdiv>
	<cmdsynopsis>
	<command>systemd-repart</command>
	<arg choice="opt" rep="repeat">OPTIONS</arg>
	<arg choice="opt" rep="repeat"><replaceable><optional>BLOCKDEVICE</optional></replaceable></arg>
	</cmdsynopsis>

	<para><filename>systemd-repart.service</filename></para>
	</refsynopsisdiv>

	<refsect1>
	<title>Description</title>

	<para><command>systemd-repart</command> grows and adds partitions to a partition table, based on the
	configuration files described in
	<citerefentry><refentrytitle>repart.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
	</para>

	<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>

	<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
	minimal in size and may be augmented automatically at boot when needed, taking possession of disk space
	available but not yet used. Specifically the following use cases are among those covered:</para>

	<itemizedlist>
	<listitem><para>The root partition may be grown to cover the whole available disk space.</para></listitem>
	<listitem><para>A <filename>/home/</filename>, swap or <filename>/srv/</filename> partition can be
	added.</para></listitem>
	<listitem><para>A second (or third, …) root partition may be added, to cover A/B style setups
	where a second version of the root file system is alternatingly used for implementing update
	schemes. The deployed image would carry only a single partition ("A") but on first boot a second
	partition ("B") for this purpose is automatically created.</para></listitem>
	</itemizedlist>

	<para>The algorithm executed by <command>systemd-repart</command> is roughly as follows:</para>

	<orderedlist>
	<listitem><para>The <filename>repart.d/*.conf</filename> configuration files are loaded and parsed,
	and ordered by filename (without the directory prefix).</para></listitem>

	<listitem><para>The partition table already existing on the block device is loaded and
	parsed.</para></listitem>

	<listitem><para>The existing partitions in the partition table are matched up with the
	<filename>repart.d/*.conf</filename> files by GPT partition type UUID. The first existing partition
	of a specific type is assigned the first configuration file declaring the same type. The second
	existing partition of a specific type is then assigned the second configuration file declaring the same
	type, and so on. After this iterative assigning is complete any left-over existing partitions that have
	no matching configuration file are considered "foreign" and left as they are. And any configuration
	files for which no partition currently exists are understood as a request to create such a
	partition.</para></listitem>

	<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>

	<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>

	<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>

	<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>

	<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 new partition table is finally written to disk. The kernel is asked to reread the
	partition table.</para></listitem>
	</orderedlist>

	<para>As exception to the normally strictly incremental operation, when called in a special "factory
	reset" mode, <command>systemd-repart</command> may also be used to erase existing partitions to
	reset an installation back to vendor defaults. This mode of operation is used when either the
	<option>--factory-reset=yes</option> switch is passed on the tool's command line, or the
	<option>systemd.factory_reset=yes</option> option specified on the kernel command line, or the
	<varname>FactoryReset</varname> EFI variable (vendor UUID
	<constant>8cf2644b-4b0b-428f-9387-6d876050dc67</constant>) is set to "yes". It alters the algorithm above
	slightly: between the 3rd and the 4th step above any partition marked explicitly via the
	<varname>FactoryReset=</varname> boolean is deleted, and the algorithm restarted, thus immediately
	re-creating these partitions anew empty.</para>

	<para>Note that <command>systemd-repart</command> only changes partition tables, it does not create or
	resize any file systems within these partitions. A separate mechanism should be used for that, for
	example
	<citerefentry><refentrytitle>systemd-growfs</refentrytitle><manvolnum>8</manvolnum></citerefentry> and
	<command>systemd-makefs</command>.</para>

	<para>The UUIDs identifying the new partitions created (or assigned to existing partitions that have no
	UUID yet), as well as the disk as a whole are hashed cryptographically from a common seed value. This
	seed value is usually the
	<citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> of the
	system, so that the machine ID reproducibly determines the UUIDs assigned to all partitions. If the
	machine ID cannot be read (or the user passes <option>--seed=random</option>, see below) the seed is
	generated randomly instead, so that the partition UUIDs are also effectively random. The seed value may
	also be set explicitly, formatted as UUID via the <option>--seed=</option> option. By hashing these UUIDs
	from a common seed images prepared with this tool become reproducible and the result of the algorithm
	above deterministic.</para>

	<para>The positional argument should specify the block device to operate on. Instead of a block device
	node path a regular file may be specified too, in which case the command operates on it like it would if
	a loopback block device node was specified with the file attached. If <option>--empty=create</option> is
	specified the specified path is created as regular file, which is useful for generating disk images from
	scratch.</para>
	</refsect1>

	<refsect1>
	<title>Options</title>

	<para>The following options are understood:</para>

	<variablelist>
	<varlistentry>
	<term><option>--dry-run=</option></term>
	<listitem><para>Takes a boolean. If this switch is not specified <option>--dry-run=yes</option> is
	the implied default. Controls whether <filename>systemd-repart</filename> executes the requested
	re-partition operations or whether it should only show what it would do. Unless
	<option>--dry-run=no</option> is specified <filename>systemd-repart</filename> will not actually
	touch the device's partition table.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--empty=</option></term>
	<listitem><para>Takes one of <literal>refuse</literal>, <literal>allow</literal>,
	<literal>require</literal>, <literal>force</literal> or <literal>create</literal>. Controls how to
	operate on block devices that are entirely empty, i.e. carry no partition table/disk label yet. If
	this switch is not specified the implied default is <literal>refuse</literal>.</para>

	<para>If <literal>refuse</literal> <command>systemd-repart</command> requires that the block device
	it shall operate on already carries a partition table and refuses operation if none is found. If
	<literal>allow</literal> the command will extend an existing partition table or create a new one if
	none exists. If <literal>require</literal> the command will create a new partition table if none
	exists so far, and refuse operation if one already exists. If <literal>force</literal> it will create
	a fresh partition table unconditionally, erasing the disk fully in effect. If
	<literal>force</literal> no existing partitions will be taken into account or survive the
	operation. Hence: use with care, this is a great way to lose all your data. If
	<literal>create</literal> a new loopback file is create under the path passed via the device node
	parameter, of the size indicated with <option>--size=</option>, see below.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--discard=</option></term>

	<listitem><para>Takes a boolean. If this switch is not specified <option>--discard=yes</option> is
	the implied default. Controls whether to issue the <constant>BLKDISCARD</constant> I/O control
	command on the space taken up by any added partitions or on the space in between them. Usually, it's
	a good idea to issue this request since it tells the underlying hardware that the covered blocks
	shall be considered empty, improving performance. If operating on a regular file instead of a block
	device node, a sparse file is generated.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--size=</option></term>

	<listitem><para>Takes a size in bytes, using the usual K, M, G, T suffixes, or the special value
	<literal>auto</literal>. If used the specified device node path must refer to a regular file, which
	is then grown to the specified size if smaller, before any change is made to the partition table. If
	specified as <literal>auto</literal> the minimal size for the disk image is automatically determined
	(i.e. the minimal sizes of all partitions are summed up, taking space for additional metadata into
	account). This switch is not supported if the specified node is a block device. This switch has no
	effect if the file is already as large as the specified size or larger. The specified size is
	implicitly rounded up to multiples of 4096. When used with <option>--empty=create</option> this
	specifies the initial size of the loopback file to create.</para>

	<para>The <option>--size=auto</option> option takes the sizes of pre-existing partitions into
	account. However, it does not accommodate for partition tables that are not tightly packed: the
	configured partitions might still not fit into the backing device if empty space exists between
	pre-existing partitions (or before the first partition) that cannot be fully filled by partitions to
	grow or create.</para>

	<para>Also note that the automatic size determination does not take files or directories specified
	with <option>CopyFiles=</option> into account: operation might fail if the specified files or
	directories require more disk space then the configured per-partition minimal size
	limit.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--factory-reset=</option></term>

	<listitem><para>Takes boolean. If this switch is not specified <option>--factory=reset=no</option> is
	the implied default. Controls whether to operate in "factory reset" mode, see above. If set to true
	this will remove all existing partitions marked with <varname>FactoryReset=</varname> set to yes
	early while executing the re-partitioning algorithm. Use with care, this is a great way to lose all
	your data. Note that partition files need to explicitly turn <varname>FactoryReset=</varname> on, as
	the option defaults to off. If no partitions are marked for factory reset this switch has no
	effect. Note that there are two other methods to request factory reset operation: via the kernel
	command line and via an EFI variable, see above.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--can-factory-reset</option></term>

	<listitem><para>If this switch is specified the disk is not re-partitioned. Instead it is determined
	if any existing partitions are marked with <varname>FactoryReset=</varname>. If there are the tool
	will exit with exit status zero, otherwise non-zero. This switch may be used to quickly determine
	whether the running system supports a factory reset mechanism built on
	<command>systemd-repart</command>.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--root=</option></term>

	<listitem><para>Takes a path to a directory to use as root file system when searching for
	<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>
	</varlistentry>

	<varlistentry>
	<term><option>--image=</option></term>

	<listitem><para>Takes a path to a disk image file or device to mount and use in a similar fashion to
	<option>--root=</option>, see above.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--seed=</option></term>

	<listitem><para>Takes a UUID as argument or the special value <constant>random</constant>. If a UUID
	is specified the UUIDs to assign to partitions and the partition table itself are derived via
	cryptographic hashing from it. If not specified it is attempted to read the machine ID from the host
	(or more precisely, the root directory configured via <option>--root=</option>) and use it as seed
	instead, falling back to a randomized seed otherwise. Use <option>--seed=random</option> to force a
	randomized seed. Explicitly specifying the seed may be used to generated strictly reproducible
	partition tables.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--pretty=</option></term>

	<listitem><para>Takes a boolean argument. If this switch is not specified, it defaults to on when
	called from an interactive terminal and off otherwise. Controls whether to show a user friendly table
	and graphic illustrating the changes applied.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--definitions=</option></term>

	<listitem><para>Takes a file system path. If specified the <filename>*.conf</filename> files are read
	from the specified directory instead of searching in <filename>/usr/lib/repart.d/*.conf</filename>,
	<filename>/etc/repart.d/*.conf</filename>,
	<filename>/run/repart.d/*.conf</filename>.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--key-file=</option></term>

	<listitem><para>Takes a file system path. Configures the encryption key to use when setting up LUKS2
	volumes configured with the <varname>Encrypt=key-file</varname> setting in partition files. Should
	refer to a regular file containing the key, or an <constant>AF_UNIX</constant> stream socket in the
	file system. In the latter case a connection is made to it and the key read from it. If this switch
	is not specified the empty key (i.e. zero length key) is used. This behaviour is useful for setting
	up encrypted partitions during early first boot that receive their user-supplied password only in a
	later setup step.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><option>--tpm2-device=</option></term>
	<term><option>--tpm2-pcrs=</option></term>

	<listitem><para>Configures the TPM2 device and list of PCRs to use for LUKS2 volumes configured with
	the <varname>Encrypt=tpm2</varname> option. These options take the same parameters as the identically
	named options to
	<citerefentry><refentrytitle>systemd-cryptenroll</refentrytitle><manvolnum>1</manvolnum></citerefentry>
	and have the same effect on partitions where TPM2 enrollment is requested.</para></listitem>
	</varlistentry>

	<xi:include href="standard-options.xml" xpointer="help" />
	<xi:include href="standard-options.xml" xpointer="version" />
	<xi:include href="standard-options.xml" xpointer="no-pager" />
	<xi:include href="standard-options.xml" xpointer="no-legend" />
	<xi:include href="standard-options.xml" xpointer="json" />
	</variablelist>
	</refsect1>

	<refsect1>
	<title>Exit status</title>

	<para>On success, 0 is returned, a non-zero failure code otherwise.</para>
	</refsect1>

	<refsect1>
	<title>See Also</title>
	<para>
	<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>repart.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>systemd-cryptenroll</refentrytitle><manvolnum>1</manvolnum></citerefentry>
	</para>
	</refsect1>

	</refentry>