[thirdparty/systemd.git] / man / systemd-gpt-auto-generator.xml

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
  SPDX-License-Identifier: LGPL-2.1+
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<refentry id="systemd-gpt-auto-generator">

  <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> and
    <filename>/srv</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> 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="http://www.uefi.org/specifications">UEFI Specification</ulink>, chapter 5.
    It implements the <ulink
    url="https://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable
    Partitions Specification</ulink>. Note that this generator has no
    effect on non-GPT systems, or where the directories under the
    mount points are already non-empty. 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 root partitions on the
    same physical disk the EFI System Partition (ESP) is located on.
    It will only look for the other partitions on the same physical
    disk the root file system is located on. 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> 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="explanation" />
        <thead>
          <row>
            <entry>Partition Type GUID</entry>
            <entry>Name</entry>
            <entry>Explanation</entry>
          </row>
        </thead>
        <tbody>
          <row>
            <entry>44479540-f297-41b2-9af7-d131d5f0458a</entry>
            <entry><filename>Root Partition (x86)</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>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>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>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>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>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>The first server data partition on the disk the root partition is located on is mounted to <filename>/srv</filename>.</entry>
          </row>
          <row>
            <entry>0657fd6d-a4ab-43c4-84e5-0933c84b4f4f</entry>
            <entry>Swap</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>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>
        </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>/srv</filename>, <filename>/home</filename></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>/srv</filename>, <filename>/home</filename></entry>
            <entry>Partition is not mounted automatically</entry>
          </row>

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

    <para>The <filename>/home</filename> and <filename>/srv</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> and
    <filename>/dev/mapper/srv</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>Mount and automount units for the EFI System Partition (ESP) are generated on EFI systems. The ESP is mounted
    to <filename>/boot</filename>, 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>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>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 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>
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d67ca9ab LP	1	<?xml version="1.0"?>
d67ca9ab LP	2	<!---nxml--->
12b42c76	3	<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
d67ca9ab	4	<!--
572eb058	5	SPDX-License-Identifier: LGPL-2.1+
d67ca9ab LP	6	-->
	7	<refentry id="systemd-gpt-auto-generator">
	8
798d3a52 ZJS	9	<refentryinfo>
	10	<title>systemd-gpt-auto-generator</title>
	11	<productname>systemd</productname>
798d3a52 ZJS	12	</refentryinfo>
	13
	14	<refmeta>
	15	<refentrytitle>systemd-gpt-auto-generator</refentrytitle>
	16	<manvolnum>8</manvolnum>
	17	</refmeta>
	18
	19	<refnamediv>
	20	<refname>systemd-gpt-auto-generator</refname>
	21	<refpurpose>Generator for automatically discovering
	22	and mounting root, <filename>/home</filename> and
	23	<filename>/srv</filename> partitions, as well as
	24	discovering and enabling swap partitions, based on GPT
	25	partition type GUIDs.</refpurpose>
	26	</refnamediv>
	27
	28	<refsynopsisdiv>
12b42c76	29	<para><filename>/usr/lib/systemd/system-generators/systemd-gpt-auto-generator</filename></para>
798d3a52 ZJS	30	</refsynopsisdiv>
	31
	32	<refsect1>
	33	<title>Description</title>
	34
	35	<para><filename>systemd-gpt-auto-generator</filename> is a unit
	36	generator that automatically discovers root,
	37	<filename>/home</filename>, <filename>/srv</filename> and swap
	38	partitions and creates mount and swap units for them, based on the
8d5a4f27 ZJS	39	partition type GUIDs of GUID partition tables (GPT),
	40	see <ulink url="http://www.uefi.org/specifications">UEFI Specification</ulink>, chapter 5.
	41	It implements the <ulink
28a0ad81	42	url="https://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable
798d3a52	43	Partitions Specification</ulink>. Note that this generator has no
c6355b31 LP	44	effect on non-GPT systems, or where the directories under the
	45	mount points are already non-empty. Also, on systems where the
	46	units are explicitly configured (for example, listed in
	47	<citerefentry
	48	project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>),
dc61b7e4	49	the units this generator creates are overridden, but additional
45f09f93	50	implicit dependencies might be created.</para>
798d3a52 ZJS	51
	52	<para>This generator will only look for root partitions on the
	53	same physical disk the EFI System Partition (ESP) is located on.
	54	It will only look for the other partitions on the same physical
	55	disk the root file system is located on. These partitions will not
8d5a4f27	56	be searched for on systems where the root file system is distributed
798d3a52 ZJS	57	on multiple disks, for example via btrfs RAID.</para>
	58
	59	<para><filename>systemd-gpt-auto-generator</filename> is useful
	60	for centralizing file system configuration in the partition table
8d5a4f27 ZJS	61	and making configuration in <filename>/etc/fstab</filename> unnecessary.
8d5a4f27 ZJS	62	</para>
798d3a52 ZJS	63
	64	<para>This generator looks for the partitions based on their
	65	partition type GUID. The following partition type GUIDs are
	66	identified:</para>
	67
	68	<table>
	69	<title>Partition Type GUIDs</title>
	70	<tgroup cols='3' align='left' colsep='1' rowsep='1'>
	71	<colspec colname="guid" />
	72	<colspec colname="name" />
	73	<colspec colname="explanation" />
	74	<thead>
	75	<row>
	76	<entry>Partition Type GUID</entry>
	77	<entry>Name</entry>
	78	<entry>Explanation</entry>
	79	</row>
	80	</thead>
	81	<tbody>
	82	<row>
	83	<entry>44479540-f297-41b2-9af7-d131d5f0458a</entry>
	84	<entry><filename>Root Partition (x86)</filename></entry>
	85	<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>
	86	</row>
	87	<row>
	88	<entry>4f68bce3-e8cd-4db1-96e7-fbcaf984b709</entry>
	89	<entry><filename>Root Partition (x86-64)</filename></entry>
	90	<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>
	91	</row>
	92	<row>
	93	<entry>69dad710-2ce4-4e3c-b16c-21a1d49abed3</entry>
	94	<entry><filename>Root Partition (32-bit ARM)</filename></entry>
	95	<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>
	96	</row>
	97	<row>
	98	<entry>b921b045-1df0-41c3-af44-4c6f280d3fae</entry>
	99	<entry><filename>Root Partition (64-bit ARM)</filename></entry>
	100	<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>
	101	</row>
b793ddfa LW	102	<row>
	103	<entry>993d8d3d-f80e-4225-855a-9daf8ed7ea97</entry>
	104	<entry><filename>Root Partition (Itanium/IA-64)</filename></entry>
	105	<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>
	106	</row>
798d3a52 ZJS	107	<row>
	108	<entry>933ac7e1-2eb4-4f13-b844-0e14e2aef915</entry>
	109	<entry>Home Partition</entry>
	110	<entry>The first home partition on the disk the root partition is located on is mounted to <filename>/home</filename>.</entry>
	111	</row>
	112	<row>
	113	<entry>3b8f8425-20e0-4f3b-907f-1a25a76f98e8</entry>
	114	<entry>Server Data Partition</entry>
	115	<entry>The first server data partition on the disk the root partition is located on is mounted to <filename>/srv</filename>.</entry>
	116	</row>
	117	<row>
	118	<entry>0657fd6d-a4ab-43c4-84e5-0933c84b4f4f</entry>
	119	<entry>Swap</entry>
	120	<entry>All swap partitions located on the disk the root partition is located on are enabled.</entry>
	121	</row>
b52a109a LP	122	<row>
	123	<entry>c12a7328-f81f-11d2-ba4b-00a0c93ec93b</entry>
	124	<entry>EFI System Partition (ESP)</entry>
	125	<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>
	126	</row>
798d3a52 ZJS	127	</tbody>
	128	</tgroup>
	129	</table>
	130
8d5a4f27 ZJS	131	<para>This generator understands the following attribute flags for partitions:</para>
	132
	133	<table>
	134	<title>Partition Attributes</title>
	135	<tgroup cols='4' align='left' colsep='1' rowsep='1'>
	136	<colspec colname="attribute" />
	137	<colspec colname="value" />
	138	<colspec colname="where" />
	139	<colspec colname="explanation" />
	140	<thead>
	141	<row>
	142	<entry>Name</entry>
	143	<entry>Value</entry>
	144	<entry>Applicable to</entry>
	145	<entry>Explanation</entry>
	146	</row>
	147	</thead>
	148	<tbody>
	149	<row>
	150	<entry><constant>GPT_FLAG_READ_ONLY</constant></entry>
	151	<entry>0x1000000000000000</entry>
	152	<entry><filename>/</filename>, <filename>/srv</filename>, <filename>/home</filename></entry>
	153	<entry>Partition is mounted read-only</entry>
	154	</row>
	155
	156	<row>
	157	<entry><constant>GPT_FLAG_NO_AUTO</constant></entry>
	158	<entry>0x8000000000000000</entry>
	159	<entry><filename>/</filename>, <filename>/srv</filename>, <filename>/home</filename></entry>
	160	<entry>Partition is not mounted automatically</entry>
	161	</row>
	162
	163	<row>
	164	<entry><constant>GPT_FLAG_NO_BLOCK_IO_PROTOCOL</constant></entry>
	165	<entry>0x0000000000000002</entry>
	166	<entry>ESP</entry>
	167	<entry>Partition is not mounted automatically</entry>
	168	</row>
	169	</tbody>
	170	</tgroup>
	171	</table>
	172
798d3a52	173	<para>The <filename>/home</filename> and <filename>/srv</filename>
b938cb90	174	partitions may be encrypted in LUKS format. In this case, a device
798d3a52 ZJS	175	mapper device is set up under the names
	176	<filename>/dev/mapper/home</filename> and
	177	<filename>/dev/mapper/srv</filename>. Note that this might create
	178	conflicts if the same partition is listed in
	179	<filename>/etc/crypttab</filename> with a different device mapper
	180	device name.</para>
	181
b52a109a LP	182	<para>Mount and automount units for the EFI System Partition (ESP) are generated on EFI systems. The ESP is mounted
	183	to <filename>/boot</filename>, unless a mount point directory <filename>/efi</filename> exists, in which case it is
	184	mounted there. Since this generator creates an automount unit, the mount will only be activated on-demand, when
	185	accessed. On systems where <filename>/boot</filename> (or <filename>/efi</filename> if it exists) is an explicitly
	186	configured mount (for example, listed in <citerefentry
	187	project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>) or where the
	188	<filename>/boot</filename> (or <filename>/efi</filename>) mount point is non-empty, no mount units are
	189	generated.</para>
798d3a52 ZJS	190
	191	<para>When using this generator in conjunction with btrfs file
	192	systems, make sure to set the correct default subvolumes on them,
	193	using <command>btrfs subvolume set-default</command>.</para>
	194
	195	<para><filename>systemd-gpt-auto-generator</filename> implements
b1c1a519	196	<citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
798d3a52 ZJS	197	</refsect1>
	198
	199	<refsect1>
	200	<title>See Also</title>
	201	<para>
	202	<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
	203	<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	204	<citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	205	<citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
798d3a52	206	<citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
3ba3a79d ZJS	207	<citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
	208	<citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	209	<citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
798d3a52 ZJS	210	</para>
798d3a52 ZJS	211	</refsect1>
d67ca9ab LP	212
d67ca9ab LP	213	</refentry>