man/systemd-gpt-auto-generator.xml - systemd-stable - Rivoreo Source Code Repositories

 <?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-gpt-auto-generator" conditional='HAVE_BLKID'>

   <refentryinfo>
     <title>systemd-gpt-auto-generator</title>
     <productname>systemd</productname>
   </refentryinfo>

   <refmeta>
     <refentrytitle>systemd-gpt-auto-generator</refentrytitle>
     <manvolnum>8</manvolnum>
   </refmeta>

   <refnamediv>
     <refname>systemd-gpt-auto-generator</refname>
     <refpurpose>Generator for automatically discovering and mounting root, <filename>/home/</filename>,
     <filename>/srv/</filename>, <filename>/var/</filename> and <filename>/var/tmp/</filename> partitions, as
     well as discovering and enabling swap partitions, based on GPT partition type GUIDs</refpurpose>
   </refnamediv>

   <refsynopsisdiv>
     <para><filename>/usr/lib/systemd/system-generators/systemd-gpt-auto-generator</filename></para>
   </refsynopsisdiv>

   <refsect1>
     <title>Description</title>

     <para><filename>systemd-gpt-auto-generator</filename> is a unit generator that automatically discovers
     root, <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename>,
     <filename>/var/tmp/</filename>, the EFI System Partition, the Extended Boot Loader Partition and swap
     partitions and creates mount and swap units for them, based on the partition type GUIDs of GUID partition
     tables (GPT), see <ulink url="https://uefi.org/specifications">UEFI Specification</ulink>, chapter 5. It
     implements the <ulink url="https://systemd.io/DISCOVERABLE_PARTITIONS">Discoverable Partitions
     Specification</ulink>. Note that this generator has no effect on non-GPT systems, and on specific mount
     points that are directories already containing files. Also, on systems where the units are explicitly
     configured (for example, listed in <citerefentry
     project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>), the
     units this generator creates are overridden, but additional implicit dependencies might be
     created.</para>

     <para>This generator will only look for the root partition on the same physical disk the EFI System
     Partition (ESP) is located on. Note that support from the boot loader is required: the EFI variable
     <varname>LoaderDevicePartUUID</varname> of the <constant>4a67b082-0a4c-41cf-b6c7-440b29bb8c4f</constant>
     vendor UUID is used to determine from which partition, and hence the disk from which the system was
     booted. If the boot loader does not set this variable, this generator will not be able to autodetect the
     root partition. See the <ulink url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader
     Interface</ulink> for details.</para>

     <para>Similarly, this generator will only look for the other partitions on the same physical disk as the
     root partition. In this case, boot loader support is not required. These partitions will not be searched
     for on systems where the root file system is distributed on multiple disks, for example via btrfs RAID.
     </para>

     <para><filename>systemd-gpt-auto-generator</filename> is useful for centralizing file system
     configuration in the partition table and making configuration in <filename>/etc/fstab</filename> or on
     the kernel command line unnecessary.</para>

     <para>This generator looks for the partitions based on their
     partition type GUID. The following partition type GUIDs are
     identified:</para>

     <table>
       <title>Partition Type GUIDs</title>
       <tgroup cols='3' align='left' colsep='1' rowsep='1'>
         <colspec colname="guid" />
         <colspec colname="name" />
         <colspec colname="where" />
         <colspec colname="explanation" />
         <thead>
           <row>
             <entry>Partition Type GUID</entry>
             <entry>Name</entry>
             <entry>Mount Point</entry>
             <entry>Explanation</entry>
           </row>
         </thead>
         <tbody>
           <row>
             <entry>44479540-f297-41b2-9af7-d131d5f0458a</entry>
             <entry><filename>Root Partition (x86)</filename></entry>
             <entry><filename>/</filename></entry>
             <entry>On 32-bit x86 systems, the first x86 root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
           </row>
           <row>
             <entry>4f68bce3-e8cd-4db1-96e7-fbcaf984b709</entry>
             <entry><filename>Root Partition (x86-64)</filename></entry>
             <entry><filename>/</filename></entry>
             <entry>On 64-bit x86 systems, the first x86-64 root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
           </row>
           <row>
             <entry>69dad710-2ce4-4e3c-b16c-21a1d49abed3</entry>
             <entry><filename>Root Partition (32-bit ARM)</filename></entry>
             <entry><filename>/</filename></entry>
             <entry>On 32-bit ARM systems, the first ARM root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
           </row>
           <row>
             <entry>b921b045-1df0-41c3-af44-4c6f280d3fae</entry>
             <entry><filename>Root Partition (64-bit ARM)</filename></entry>
             <entry><filename>/</filename></entry>
             <entry>On 64-bit ARM systems, the first ARM root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
           </row>
           <row>
             <entry>993d8d3d-f80e-4225-855a-9daf8ed7ea97</entry>
             <entry><filename>Root Partition (Itanium/IA-64)</filename></entry>
             <entry><filename>/</filename></entry>
             <entry>On Itanium systems, the first Itanium root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
           </row>
           <row>
             <entry>933ac7e1-2eb4-4f13-b844-0e14e2aef915</entry>
             <entry>Home Partition</entry>
             <entry><filename>/home/</filename></entry>
             <entry>The first home partition on the disk the root partition is located on is mounted to <filename>/home/</filename>.</entry>
           </row>
           <row>
             <entry>3b8f8425-20e0-4f3b-907f-1a25a76f98e8</entry>
             <entry>Server Data Partition</entry>
             <entry><filename>/srv/</filename></entry>
             <entry>The first server data partition on the disk the root partition is located on is mounted to <filename>/srv/</filename>.</entry>
           </row>
           <row>
             <entry>4d21b016-b534-45c2-a9fb-5c16e091fd2d</entry>
             <entry>Variable Data Partition</entry>
             <entry><filename>/var/</filename></entry>
             <entry>The first variable data partition on the disk the root partition is located on is mounted to <filename>/var/</filename> — under the condition its partition UUID matches the first 128 bit of the HMAC-SHA256 of the GPT type uuid of this partition keyed by the machine ID of the installation stored in <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</entry>
           </row>
           <row>
             <entry>7ec6f557-3bc5-4aca-b293-16ef5df639d1</entry>
             <entry>Temporary Data Partition</entry>
             <entry><filename>/var/tmp/</filename></entry>
             <entry>The first temporary data partition on the disk the root partition is located on is mounted to <filename>/var/tmp/</filename>.</entry>
           </row>
           <row>
             <entry>0657fd6d-a4ab-43c4-84e5-0933c84b4f4f</entry>
             <entry>Swap</entry>
             <entry>n/a</entry>
             <entry>All swap partitions located on the disk the root partition is located on are enabled.</entry>
           </row>
           <row>
             <entry>c12a7328-f81f-11d2-ba4b-00a0c93ec93b</entry>
             <entry>EFI System Partition (ESP)</entry>
             <entry><filename>/efi/</filename> or <filename>/boot/</filename></entry>
             <entry>The first ESP located on the disk the root partition is located on is mounted to <filename>/boot/</filename> or <filename>/efi/</filename>, see below.</entry>
           </row>
           <row>
             <entry>bc13c2ff-59e6-4262-a352-b275fd6f7172</entry>
             <entry>Extended Boot Loader Partition</entry>
             <entry><filename>/boot/</filename></entry>
             <entry>The first Extended Boot Loader Partition is mounted to <filename>/boot/</filename>, see below.</entry>
           </row>
         </tbody>
       </tgroup>
     </table>

     <para>This generator understands the following attribute flags for partitions:</para>

     <table>
       <title>Partition Attributes</title>
       <tgroup cols='4' align='left' colsep='1' rowsep='1'>
         <colspec colname="attribute" />
         <colspec colname="value" />
         <colspec colname="where" />
         <colspec colname="explanation" />
         <thead>
           <row>
             <entry>Name</entry>
             <entry>Value</entry>
             <entry>Applicable to</entry>
             <entry>Explanation</entry>
           </row>
         </thead>
         <tbody>
           <row>
             <entry><constant>GPT_FLAG_READ_ONLY</constant></entry>
             <entry>0x1000000000000000</entry>
             <entry><filename>/</filename>, <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename>, <filename>/var/tmp/</filename>, Extended Boot Loader Partition</entry>
             <entry>Partition is mounted read-only</entry>
           </row>

           <row>
             <entry><constant>GPT_FLAG_NO_AUTO</constant></entry>
             <entry>0x8000000000000000</entry>
             <entry><filename>/</filename>, <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename>, <filename>/var/tmp/</filename>, Extended Boot Loader Partition</entry>
             <entry>Partition is not mounted automatically</entry>
           </row>

           <row>
             <entry><constant>GPT_FLAG_NO_BLOCK_IO_PROTOCOL</constant></entry>
             <entry>0x0000000000000002</entry>
             <entry>EFI System Partition (ESP)</entry>
             <entry>Partition is not mounted automatically</entry>
           </row>
         </tbody>
       </tgroup>
     </table>

     <para>The <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename> and
     <filename>/var/tmp/</filename> partitions may be encrypted in LUKS format. In this case, a device mapper
     device is set up under the names <filename>/dev/mapper/home</filename>,
     <filename>/dev/mapper/srv</filename>, <filename>/dev/mapper/var</filename> and
     <filename>/dev/mapper/tmp</filename>. Note that this might create conflicts if the same partition is
     listed in <filename>/etc/crypttab</filename> with a different device mapper device name.</para>

     <para>When systemd is running in the initrd the <filename>/</filename> partition may be encrypted in LUKS
       format as well. In this case, a device mapper device is set up under the name <filename>/dev/mapper/root</filename>,
       and a <filename>sysroot.mount</filename> is set up that mounts the device under <filename>/sysroot</filename>.
       For more information, see <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
     </para>

     <para>Mount and automount units for the EFI System Partition (ESP) are generated on EFI systems. The ESP
     is mounted to <filename>/boot/</filename> (except if an Extended Boot Loader partition exists, see
     below), unless a mount point directory <filename>/efi/</filename> exists, in which case it is mounted
     there. Since this generator creates an automount unit, the mount will only be activated on-demand, when
     accessed. On systems where <filename>/boot/</filename> (or <filename>/efi/</filename> if it exists) is an
     explicitly configured mount (for example, listed in <citerefentry
     project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>) or where
     the <filename>/boot/</filename> (or <filename>/efi/</filename>) mount point is non-empty, no mount units
     are generated.</para>

     <para>If the disk contains an Extended Boot Loader partition, as defined in the <ulink
     url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>, it is made
     available at <filename>/boot/</filename> (by means of an automount point, similar to the ESP, see
     above). If both an EFI System Partition and an Extended Boot Loader partition exist the latter is
     preferably mounted to <filename>/boot/</filename>. Make sure to create both <filename>/efi/</filename>
     and <filename>/boot/</filename> to ensure both partitions are mounted.</para>

     <para>When using this generator in conjunction with btrfs file
     systems, make sure to set the correct default subvolumes on them,
     using <command>btrfs subvolume set-default</command>.</para>

     <para><filename>systemd-gpt-auto-generator</filename> implements
     <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
   </refsect1>

   <refsect1>
     <title>Kernel Command Line</title>

     <para><filename>systemd-gpt-auto-generator</filename> understands the following kernel command line
     parameters:</para>

     <variablelist class='kernel-commandline-options'>

       <varlistentry>
         <term><varname>systemd.gpt_auto</varname></term>
         <term><varname>rd.systemd.gpt_auto</varname></term>

         <listitem><para>Those options take an optional boolean argument, and default to yes.
         The generator is enabled by default, and a negative value may be used to disable it.
         </para></listitem>
       </varlistentry>

       <varlistentry>
         <term><varname>root=</varname></term>

         <listitem><para>When used with the special value <literal>gpt-auto</literal>, automatic discovery of
         the root partition based on the GPT partition type is enabled.  Any other value disables this
         generator.</para></listitem>
       </varlistentry>

       <varlistentry>
         <term><varname>rw</varname></term>
         <term><varname>ro</varname></term>

         <listitem><para>Mount the root partition read-write or read-only <emphasis>initially</emphasis>.</para>

         <para>Note that unlike most kernel command line options these settings do not override configuration
         in the file system, and the file system may be remounted later. See
         <citerefentry><refentrytitle>systemd-remount-fs.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
         </para></listitem>
       </varlistentry>
     </variablelist>
   </refsect1>

   <refsect1>
     <title>See Also</title>
     <para>
       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
       <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
       <citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</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-gpt-auto-generator" conditional='HAVE_BLKID'>

	<refentryinfo>
	<title>systemd-gpt-auto-generator</title>
	<productname>systemd</productname>
	</refentryinfo>

	<refmeta>
	<refentrytitle>systemd-gpt-auto-generator</refentrytitle>
	<manvolnum>8</manvolnum>
	</refmeta>

	<refnamediv>
	<refname>systemd-gpt-auto-generator</refname>
	<refpurpose>Generator for automatically discovering and mounting root, <filename>/home/</filename>,
	<filename>/srv/</filename>, <filename>/var/</filename> and <filename>/var/tmp/</filename> partitions, as
	well as discovering and enabling swap partitions, based on GPT partition type GUIDs</refpurpose>
	</refnamediv>

	<refsynopsisdiv>
	<para><filename>/usr/lib/systemd/system-generators/systemd-gpt-auto-generator</filename></para>
	</refsynopsisdiv>

	<refsect1>
	<title>Description</title>

	<para><filename>systemd-gpt-auto-generator</filename> is a unit generator that automatically discovers
	root, <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename>,
	<filename>/var/tmp/</filename>, the EFI System Partition, the Extended Boot Loader Partition and swap
	partitions and creates mount and swap units for them, based on the partition type GUIDs of GUID partition
	tables (GPT), see <ulink url="https://uefi.org/specifications">UEFI Specification</ulink>, chapter 5. It
	implements the <ulink url="https://systemd.io/DISCOVERABLE_PARTITIONS">Discoverable Partitions
	Specification</ulink>. Note that this generator has no effect on non-GPT systems, and on specific mount
	points that are directories already containing files. Also, on systems where the units are explicitly
	configured (for example, listed in <citerefentry
	project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>), the
	units this generator creates are overridden, but additional implicit dependencies might be
	created.</para>

	<para>This generator will only look for the root partition on the same physical disk the EFI System
	Partition (ESP) is located on. Note that support from the boot loader is required: the EFI variable
	<varname>LoaderDevicePartUUID</varname> of the <constant>4a67b082-0a4c-41cf-b6c7-440b29bb8c4f</constant>
	vendor UUID is used to determine from which partition, and hence the disk from which the system was
	booted. If the boot loader does not set this variable, this generator will not be able to autodetect the
	root partition. See the <ulink url="https://systemd.io/BOOT_LOADER_INTERFACE">Boot Loader
	Interface</ulink> for details.</para>

	<para>Similarly, this generator will only look for the other partitions on the same physical disk as the
	root partition. In this case, boot loader support is not required. These partitions will not be searched
	for on systems where the root file system is distributed on multiple disks, for example via btrfs RAID.
	</para>

	<para><filename>systemd-gpt-auto-generator</filename> is useful for centralizing file system
	configuration in the partition table and making configuration in <filename>/etc/fstab</filename> or on
	the kernel command line unnecessary.</para>

	<para>This generator looks for the partitions based on their
	partition type GUID. The following partition type GUIDs are
	identified:</para>

	<table>
	<title>Partition Type GUIDs</title>
	<tgroup cols='3' align='left' colsep='1' rowsep='1'>
	<colspec colname="guid" />
	<colspec colname="name" />
	<colspec colname="where" />
	<colspec colname="explanation" />
	<thead>
	<row>
	<entry>Partition Type GUID</entry>
	<entry>Name</entry>
	<entry>Mount Point</entry>
	<entry>Explanation</entry>
	</row>
	</thead>
	<tbody>
	<row>
	<entry>44479540-f297-41b2-9af7-d131d5f0458a</entry>
	<entry><filename>Root Partition (x86)</filename></entry>
	<entry><filename>/</filename></entry>
	<entry>On 32-bit x86 systems, the first x86 root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
	</row>
	<row>
	<entry>4f68bce3-e8cd-4db1-96e7-fbcaf984b709</entry>
	<entry><filename>Root Partition (x86-64)</filename></entry>
	<entry><filename>/</filename></entry>
	<entry>On 64-bit x86 systems, the first x86-64 root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
	</row>
	<row>
	<entry>69dad710-2ce4-4e3c-b16c-21a1d49abed3</entry>
	<entry><filename>Root Partition (32-bit ARM)</filename></entry>
	<entry><filename>/</filename></entry>
	<entry>On 32-bit ARM systems, the first ARM root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
	</row>
	<row>
	<entry>b921b045-1df0-41c3-af44-4c6f280d3fae</entry>
	<entry><filename>Root Partition (64-bit ARM)</filename></entry>
	<entry><filename>/</filename></entry>
	<entry>On 64-bit ARM systems, the first ARM root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
	</row>
	<row>
	<entry>993d8d3d-f80e-4225-855a-9daf8ed7ea97</entry>
	<entry><filename>Root Partition (Itanium/IA-64)</filename></entry>
	<entry><filename>/</filename></entry>
	<entry>On Itanium systems, the first Itanium root partition on the disk the EFI ESP is located on is mounted to the root directory <filename>/</filename>.</entry>
	</row>
	<row>
	<entry>933ac7e1-2eb4-4f13-b844-0e14e2aef915</entry>
	<entry>Home Partition</entry>
	<entry><filename>/home/</filename></entry>
	<entry>The first home partition on the disk the root partition is located on is mounted to <filename>/home/</filename>.</entry>
	</row>
	<row>
	<entry>3b8f8425-20e0-4f3b-907f-1a25a76f98e8</entry>
	<entry>Server Data Partition</entry>
	<entry><filename>/srv/</filename></entry>
	<entry>The first server data partition on the disk the root partition is located on is mounted to <filename>/srv/</filename>.</entry>
	</row>
	<row>
	<entry>4d21b016-b534-45c2-a9fb-5c16e091fd2d</entry>
	<entry>Variable Data Partition</entry>
	<entry><filename>/var/</filename></entry>
	<entry>The first variable data partition on the disk the root partition is located on is mounted to <filename>/var/</filename> — under the condition its partition UUID matches the first 128 bit of the HMAC-SHA256 of the GPT type uuid of this partition keyed by the machine ID of the installation stored in <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</entry>
	</row>
	<row>
	<entry>7ec6f557-3bc5-4aca-b293-16ef5df639d1</entry>
	<entry>Temporary Data Partition</entry>
	<entry><filename>/var/tmp/</filename></entry>
	<entry>The first temporary data partition on the disk the root partition is located on is mounted to <filename>/var/tmp/</filename>.</entry>
	</row>
	<row>
	<entry>0657fd6d-a4ab-43c4-84e5-0933c84b4f4f</entry>
	<entry>Swap</entry>
	<entry>n/a</entry>
	<entry>All swap partitions located on the disk the root partition is located on are enabled.</entry>
	</row>
	<row>
	<entry>c12a7328-f81f-11d2-ba4b-00a0c93ec93b</entry>
	<entry>EFI System Partition (ESP)</entry>
	<entry><filename>/efi/</filename> or <filename>/boot/</filename></entry>
	<entry>The first ESP located on the disk the root partition is located on is mounted to <filename>/boot/</filename> or <filename>/efi/</filename>, see below.</entry>
	</row>
	<row>
	<entry>bc13c2ff-59e6-4262-a352-b275fd6f7172</entry>
	<entry>Extended Boot Loader Partition</entry>
	<entry><filename>/boot/</filename></entry>
	<entry>The first Extended Boot Loader Partition is mounted to <filename>/boot/</filename>, see below.</entry>
	</row>
	</tbody>
	</tgroup>
	</table>

	<para>This generator understands the following attribute flags for partitions:</para>

	<table>
	<title>Partition Attributes</title>
	<tgroup cols='4' align='left' colsep='1' rowsep='1'>
	<colspec colname="attribute" />
	<colspec colname="value" />
	<colspec colname="where" />
	<colspec colname="explanation" />
	<thead>
	<row>
	<entry>Name</entry>
	<entry>Value</entry>
	<entry>Applicable to</entry>
	<entry>Explanation</entry>
	</row>
	</thead>
	<tbody>
	<row>
	<entry><constant>GPT_FLAG_READ_ONLY</constant></entry>
	<entry>0x1000000000000000</entry>
	<entry><filename>/</filename>, <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename>, <filename>/var/tmp/</filename>, Extended Boot Loader Partition</entry>
	<entry>Partition is mounted read-only</entry>
	</row>

	<row>
	<entry><constant>GPT_FLAG_NO_AUTO</constant></entry>
	<entry>0x8000000000000000</entry>
	<entry><filename>/</filename>, <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename>, <filename>/var/tmp/</filename>, Extended Boot Loader Partition</entry>
	<entry>Partition is not mounted automatically</entry>
	</row>

	<row>
	<entry><constant>GPT_FLAG_NO_BLOCK_IO_PROTOCOL</constant></entry>
	<entry>0x0000000000000002</entry>
	<entry>EFI System Partition (ESP)</entry>
	<entry>Partition is not mounted automatically</entry>
	</row>
	</tbody>
	</tgroup>
	</table>

	<para>The <filename>/home/</filename>, <filename>/srv/</filename>, <filename>/var/</filename> and
	<filename>/var/tmp/</filename> partitions may be encrypted in LUKS format. In this case, a device mapper
	device is set up under the names <filename>/dev/mapper/home</filename>,
	<filename>/dev/mapper/srv</filename>, <filename>/dev/mapper/var</filename> and
	<filename>/dev/mapper/tmp</filename>. Note that this might create conflicts if the same partition is
	listed in <filename>/etc/crypttab</filename> with a different device mapper device name.</para>

	<para>When systemd is running in the initrd the <filename>/</filename> partition may be encrypted in LUKS
	format as well. In this case, a device mapper device is set up under the name <filename>/dev/mapper/root</filename>,
	and a <filename>sysroot.mount</filename> is set up that mounts the device under <filename>/sysroot</filename>.
	For more information, see <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
	</para>

	<para>Mount and automount units for the EFI System Partition (ESP) are generated on EFI systems. The ESP
	is mounted to <filename>/boot/</filename> (except if an Extended Boot Loader partition exists, see
	below), unless a mount point directory <filename>/efi/</filename> exists, in which case it is mounted
	there. Since this generator creates an automount unit, the mount will only be activated on-demand, when
	accessed. On systems where <filename>/boot/</filename> (or <filename>/efi/</filename> if it exists) is an
	explicitly configured mount (for example, listed in <citerefentry
	project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>) or where
	the <filename>/boot/</filename> (or <filename>/efi/</filename>) mount point is non-empty, no mount units
	are generated.</para>

	<para>If the disk contains an Extended Boot Loader partition, as defined in the <ulink
	url="https://systemd.io/BOOT_LOADER_SPECIFICATION">Boot Loader Specification</ulink>, it is made
	available at <filename>/boot/</filename> (by means of an automount point, similar to the ESP, see
	above). If both an EFI System Partition and an Extended Boot Loader partition exist the latter is
	preferably mounted to <filename>/boot/</filename>. Make sure to create both <filename>/efi/</filename>
	and <filename>/boot/</filename> to ensure both partitions are mounted.</para>

	<para>When using this generator in conjunction with btrfs file
	systems, make sure to set the correct default subvolumes on them,
	using <command>btrfs subvolume set-default</command>.</para>

	<para><filename>systemd-gpt-auto-generator</filename> implements
	<citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
	</refsect1>

	<refsect1>
	<title>Kernel Command Line</title>

	<para><filename>systemd-gpt-auto-generator</filename> understands the following kernel command line
	parameters:</para>

	<variablelist class='kernel-commandline-options'>

	<varlistentry>
	<term><varname>systemd.gpt_auto</varname></term>
	<term><varname>rd.systemd.gpt_auto</varname></term>

	<listitem><para>Those options take an optional boolean argument, and default to yes.
	The generator is enabled by default, and a negative value may be used to disable it.
	</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><varname>root=</varname></term>

	<listitem><para>When used with the special value <literal>gpt-auto</literal>, automatic discovery of
	the root partition based on the GPT partition type is enabled. Any other value disables this
	generator.</para></listitem>
	</varlistentry>

	<varlistentry>
	<term><varname>rw</varname></term>
	<term><varname>ro</varname></term>

	<listitem><para>Mount the root partition read-write or read-only <emphasis>initially</emphasis>.</para>

	<para>Note that unlike most kernel command line options these settings do not override configuration
	in the file system, and the file system may be remounted later. See
	<citerefentry><refentrytitle>systemd-remount-fs.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
	</para></listitem>
	</varlistentry>
	</variablelist>
	</refsect1>

	<refsect1>
	<title>See Also</title>
	<para>
	<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
	<citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	<citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
	<citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	<citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
	</para>
	</refsect1>

	</refentry>