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| <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" |
| "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
| <refentry id="repart.d" conditional='ENABLE_REPART'> |
| |
| <refentryinfo> |
| <title>repart.d</title> |
| <productname>systemd</productname> |
| </refentryinfo> |
| |
| <refmeta> |
| <refentrytitle>repart.d</refentrytitle> |
| <manvolnum>5</manvolnum> |
| </refmeta> |
| |
| <refnamediv> |
| <refname>repart.d</refname> |
| <refpurpose>Partition Definition Files for Automatic Boot-Time Repartitioning</refpurpose> |
| </refnamediv> |
| |
| <refsynopsisdiv> |
| <para><literallayout><filename>/etc/repart.d/*.conf</filename> |
| <filename>/run/repart.d/*.conf</filename> |
| <filename>/usr/lib/repart.d/*.conf</filename> |
| </literallayout></para> |
| </refsynopsisdiv> |
| |
| <refsect1> |
| <title>Description</title> |
| |
| <para><filename>repart.d/*.conf</filename> files describe basic properties of partitions of block |
| devices of the local system. They may be used to declare types, names and sizes of partitions that shall |
| exist. The |
| <citerefentry><refentrytitle>systemd-repart</refentrytitle><manvolnum>8</manvolnum></citerefentry> |
| service reads these files and attempts to add new partitions currently missing and enlarge existing |
| partitions according to these definitions. Operation is generally incremental, i.e. when applied, what |
| exists already is left intact, and partitions are never shrunk, moved or deleted.</para> |
| |
| <para>These definition files are useful for implementing operating system images that are prepared and |
| delivered with minimally sized images (for example lacking any state or swap partitions), and which on |
| first boot automatically take possession of any remaining disk space following a few basic rules.</para> |
| |
| <para>Currently, support for partition definition files is only implemented for GPT partitition |
| tables.</para> |
| |
| <para>Partition files are generally matched against any partitions already existing on disk in a simple |
| algorithm: the partition files are sorted by their filename (ignoring the directory prefix), and then |
| compared in order against existing partitions matching the same partition type UUID. Specifically, the |
| first existing partition with a specific partition type UUID is assigned the first definition file with |
| the same partition type UUID, and the second existing partition with a specific type UUID the second |
| partition file with the same type UUID, and so on. Any left-over partition files that have no matching |
| existing partition are assumed to define new partition that shall be created. Such partitions are |
| appended to the end of the partition table, in the order defined by their names utilizing the first |
| partition slot greater than the highest slot number currently in use. Any existing partitions that have |
| no matching partition file are left as they are.</para> |
| |
| <para>Note that these partition definition files do not describe the contents of the partitions, such as |
| the file system used. Separate mechanisms, such as |
| <citerefentry><refentrytitle>systemd-growfs</refentrytitle><manvolnum>8</manvolnum></citerefentry> and |
| <command>systemd-makefs</command> maybe be used to initialize or grow the file systems inside of these |
| partitions.</para> |
| </refsect1> |
| |
| <refsect1> |
| <title>[Partition] Section Options</title> |
| |
| <variablelist> |
| <varlistentry> |
| <term><varname>Type=</varname></term> |
| |
| <listitem><para>The GPT partition type UUID to match. This may be a GPT partition type UUID such as |
| <constant>4f68bce3-e8cd-4db1-96e7-fbcaf984b709</constant>, or one of the following special |
| identifiers:</para> |
| |
| <table> |
| <title>GPT partition type identifiers</title> |
| |
| <tgroup cols='2' align='left' colsep='1' rowsep='1'> |
| <colspec colname="name" /> |
| <colspec colname="explanation" /> |
| |
| <thead> |
| <row> |
| <entry>Identifier</entry> |
| <entry>Explanation</entry> |
| </row> |
| </thead> |
| |
| <tbody> |
| <row> |
| <entry><constant>esp</constant></entry> |
| <entry>EFI System Partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>xbootldr</constant></entry> |
| <entry>Extended Boot Loader Partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>swap</constant></entry> |
| <entry>Swap partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>home</constant></entry> |
| <entry>Home (<filename>/home/</filename>) partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>srv</constant></entry> |
| <entry>Server data (<filename>/srv/</filename>) partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>var</constant></entry> |
| <entry>Variable data (<filename>/var/</filename>) partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>tmp</constant></entry> |
| <entry>Temporary data (<filename>/var/tmp/</filename>) partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>linux-generic</constant></entry> |
| <entry>Generic Linux file system partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root</constant></entry> |
| <entry>Root file system partition type appropriate for the local architecture (an alias for an architecture root file system partition type listed below, e.g. <constant>root-x86-64</constant>)</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-verity</constant></entry> |
| <entry>Verity data for the root file system partition for the local architecture</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-secondary</constant></entry> |
| <entry>Root file system partition of the secondary architecture of the local architecture; usually the matching 32bit architecture for the local 64bit architecture)</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-secondary-verity</constant></entry> |
| <entry>Verity data for the root file system partition of the secondary architecture</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-x86</constant></entry> |
| <entry>Root file system partition for the x86 (32bit, aka i386) architecture</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-x86-verity</constant></entry> |
| <entry>Verity data for the x86 (32bit) root file system partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-x86-64</constant></entry> |
| <entry>Root file system partition for the x86_64 (64bit, aka amd64) architecture</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-x86-64-verity</constant></entry> |
| <entry>Verity data for the x86_64 (64bit) root file system partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-arm</constant></entry> |
| <entry>Root file system partition for the ARM (32bit) architecture</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-arm-verity</constant></entry> |
| <entry>Verity data for the ARM (32bit) root file system partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-arm64</constant></entry> |
| <entry>Root file system partition for the ARM (64bit, aka aarch64) architecture</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-arm64-verity</constant></entry> |
| <entry>Verity data for the ARM (64bit, aka aarch64) root file system partition</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-ia64</constant></entry> |
| <entry>Root file system partition for the ia64 architecture</entry> |
| </row> |
| |
| <row> |
| <entry><constant>root-ia64-verity</constant></entry> |
| <entry>Verity data for the ia64 root file system partition</entry> |
| </row> |
| </tbody> |
| </tgroup> |
| </table> |
| |
| <para>This setting defaults to <constant>linux-generic</constant>.</para> |
| |
| <para>Most of the partition type UUIDs listed above are defined in the <ulink |
| url="https://systemd.io/DISCOVERABLE_PARTITIONS">Discoverable Partitions |
| Specification</ulink>.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>Label=</varname></term> |
| |
| <listitem><para>The textual label to assign to the partition if none is assigned yet. Note that this |
| setting is not used for matching. It is also not used when a label is already set for an existing |
| partition. It is thus only used when a partition is newly created or when an existing one had a no |
| label set (that is: an empty label). If not specified a label derived from the partition type is |
| automatically used.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>Priority=</varname></term> |
| |
| <listitem><para>A numeric priority to assign to this partition, in the range -2147483648…2147483647, |
| with smaller values indicating higher priority, and higher values indicating smaller priority. This |
| priority is used in case the configured size constraints on the defined partitions do not permit |
| fitting all partitions onto the available disk space. If the partitions do not fit, the highest |
| numeric partition priority of all defined partitions is determined, and all defined partitions with |
| this priority are removed from the list of new partitions to create (which may be multiple, if the |
| same priority is used for multiple partitions). The fitting algorithm is then tried again. If the |
| partitions still do not fit, the now highest numeric partition priority is determined, and the |
| matching partitions removed too, and so on. Partitions of a priority of 0 or lower are never |
| removed. If all partitions with a priority above 0 are removed and the partitions still do not fit on |
| the device the operation fails. Note that this priority has no effect on ordering partitions, for |
| that use the alphabetical order of the filenames of the partition definition files. Defaults to |
| 0.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>Weight=</varname></term> |
| |
| <listitem><para>A numeric weight to assign to this partition in the range 0…1000000. Available disk |
| space is assigned the defined partitions according to their relative weights (subject to the size |
| constraints configured with <varname>SizeMinBytes=</varname>, <varname>SizeMaxBytes=</varname>), so |
| that a partition with weight 2000 gets double the space as one with weight 1000, and a partition with |
| weight 333 a third of that. Defaults to 1000.</para> |
| |
| <para>The <varname>Weight=</varname> setting is used to distribute available disk space in an |
| "elastic" fashion, based on the disk size and existing partitions. If a partition shall have a fixed |
| size use both <varname>SizeMinBytes=</varname> and <varname>SizeMaxBytes=</varname> with the same |
| value in order to fixate the size to one value, in which case the weight has no |
| effect.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>PaddingWeight=</varname></term> |
| |
| <listitem><para>Similar to <varname>Weight=</varname> but sets a weight for the free space after the |
| partition (the "padding"). When distributing available space the weights of all partitions and all |
| defined padding is summed, and then each partition and padding gets the fraction defined by its |
| weight. Defaults to 0, i.e. by default no padding is applied.</para> |
| |
| <para>Padding is useful if empty space shall be left for later additions or a safety margin at the |
| end of the device or between partitions.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>SizeMinBytes=</varname></term> |
| <term><varname>SizeMaxBytes=</varname></term> |
| |
| <listitem><para>Specifies minimum and maximum size constraints in bytes. Takes the usual K, M, G, T, |
| … suffixes (to the base of 1024). If <varname>SizeMinBytes=</varname> is specified the partition is |
| created at or grown to at least the specified size. If <varname>SizeMaxBytes=</varname> is specified |
| the partition is created at or grown to at most the specified size. The precise size is determined |
| through the weight value value configured with <varname>Weight=</varname>, see above. When |
| <varname>SizeMinBytes=</varname> is set equal to <varname>SizeMaxBytes=</varname> the configured |
| weight has no effect as the partition is explicitly sized to the specified fixed value. Note that |
| partitions are never created smaller than 4096 bytes, and since partitions are never shrunk the |
| previous size of the partition (in case the partition already exists) is also enforced as lower bound |
| for the new size. The values should be specified as multiples of 4096 bytes, and are rounded upwards |
| (in case of <varname>SizeMinBytes=</varname>) or downwards (in case of |
| <varname>SizeMaxBytes=</varname>) otherwise. If the backing device does not provide enough space to |
| fulfill the constraints placing the partition will fail. For partitions that shall be created, |
| depending on the setting of <varname>Priority=</varname> (see above) the partition might be dropped |
| and the placing algorithm restarted. By default a minimum size constraint of 10M and no maximum size |
| constraint is set.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>PaddingMinBytes=</varname></term> |
| <term><varname>PaddingMaxBytes=</varname></term> |
| |
| <listitem><para>Specifies minimum and maximum size constrains in bytes for the free space after the |
| partition (the "padding"). Semantics are similar to <varname>SizeMinBytes=</varname> and |
| <varname>SizeMaxBytes=</varname>, except that unlike partition sizes free space can be shrunk and can |
| be as small as zero. By default no size constraints on padding are set, so that only |
| <varname>PaddingWeight=</varname> determines the size of the padding applied.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>FactoryReset=</varname></term> |
| |
| <listitem><para>Takes a boolean argument. If specified the partition is marked for removal during a |
| factory reset operation. This functionality is useful to implement schemes where images can be reset |
| into their original state by removing partitions and creating them anew. Defaults to off.</para></listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>Examples</title> |
| |
| <example> |
| <title>Grow the root partition to the full disk size at first boot</title> |
| |
| <para>With the following file the root partition is automatically grown to the full disk if possible during boot.</para> |
| |
| <para><programlisting># /usr/lib/repart.d/50-root.conf |
| [Partition] |
| Type=root |
| </programlisting></para> |
| </example> |
| |
| <example> |
| <title>Create a swap and home partition automatically on boot, if missing</title> |
| |
| <para>The home partition gets all available disk space while the swap partition gets 1G at most and 64M |
| at least. We set a priority > 0 on the swap partition to ensure the swap partition is not used if not |
| enough space is available. For every three bytes assigned to the home partition the swap partition gets |
| assigned one.</para> |
| |
| <para><programlisting># /usr/lib/repart.d/60-home.conf |
| [Partition] |
| Type=home |
| </programlisting></para> |
| |
| <para><programlisting># /usr/lib/repart.d/70-swap.conf |
| [Partition] |
| Type=swap |
| SizeMinBytes=64M |
| SizeMaxBytes=1G |
| Priority=1 |
| Weight=333 |
| </programlisting></para> |
| </example> |
| |
| <example> |
| <title>Create B partitions in an A/B Verity setup, if missing</title> |
| |
| <para>Let's say the vendor intends to update OS images in an A/B setup, i.e. with two root partitions |
| (and two matching Verity partitions) that shall be used alternatingly during upgrades. To minimize |
| image sizes the original image is shipped only with one root and one Verity partition (the "A" set), |
| and the second root and Verity partitions (the "B" set) shall be created on first boot on the free |
| space on the medium.</para> |
| |
| <para><programlisting># /usr/lib/repart.d/50-root.conf |
| [Partition] |
| Type=root |
| SizeMinBytes=512M |
| SizeMaxBytes=512M |
| </programlisting></para> |
| |
| <para><programlisting># /usr/lib/repart.d/60-root-verity.conf |
| [Partition] |
| Type=root-verity |
| SizeMinBytes=64M |
| SizeMaxBytes=64M |
| </programlisting></para> |
| |
| <para>The definitions above cover the "A" set of root partition (of a fixed 512M size) and Verity |
| partition for the root partition (of a fixed 64M size). Let's use symlinks to create the "B" set of |
| partitions, since after all they shall have the same properties and sizes as the "A" set.</para> |
| |
| <para><programlisting># ln -s 50-root.conf /usr/lib/repart.d/70-root-b.conf |
| # ln -s 60-root-verity.conf /usr/lib/repart.d/80-root-verity-b.conf |
| </programlisting></para> |
| </example> |
| |
| </refsect1> |
| |
| <refsect1> |
| <title>See Also</title> |
| <para> |
| <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
| <citerefentry><refentrytitle>systemd-repart</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
| <citerefentry project='man-pages'><refentrytitle>sfdisk</refentrytitle><manvolnum>8</manvolnum></citerefentry> |
| </para> |
| </refsect1> |
| |
| </refentry> |