man/systemd-gpt-auto-generator.xml

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  10   Copyright 2013 Lennart Poettering
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  25 <refentry id="systemd-gpt-auto-generator">
  26
  27   <refentryinfo>
  28     <title>systemd-gpt-auto-generator</title>
  29     <productname>systemd</productname>
  30
  31     <authorgroup>
  32       <author>
  33         <contrib>Developer</contrib>
  34         <firstname>Lennart</firstname>
  35         <surname>Poettering</surname>
  36         <email>lennart@poettering.net</email>
  37       </author>
  38     </authorgroup>
  39   </refentryinfo>
  40
  41   <refmeta>
  42     <refentrytitle>systemd-gpt-auto-generator</refentrytitle>
  43     <manvolnum>8</manvolnum>
  44   </refmeta>
  45
  46   <refnamediv>
  47     <refname>systemd-gpt-auto-generator</refname>
  48     <refpurpose>Generator for automatically discovering
  49     and mounting root, <filename>/home</filename> and
  50     <filename>/srv</filename> partitions, as well as
  51     discovering and enabling swap partitions, based on GPT
  52     partition type GUIDs.</refpurpose>
  53   </refnamediv>
  54
  55   <refsynopsisdiv>
  56     <para><filename>&rootlibexecdir;/system-generators/systemd-gpt-auto-generator</filename></para>
  57   </refsynopsisdiv>
  58
  59   <refsect1>
  60     <title>Description</title>
  61
  62     <para><filename>systemd-gpt-auto-generator</filename> is a unit
  63     generator that automatically discovers root,
  64     <filename>/home</filename>, <filename>/srv</filename> and swap
  65     partitions and creates mount and swap units for them, based on the
  66     partition type GUIDs of GUID partition tables (GPT). It implements
  67     the
  68     <ulink url="http://www.freedesktop.org/wiki/Specifications/DiscoverablePartitionsSpec/">Discoverable
  69     Partitions Specification</ulink>. Note that this generator has no
  70     effect on non-GPT systems, on systems where the units are
  71     explicitly configured (for example, listed in
  72     <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>),
  73     or where the mount points are non-empty.</para>
  74
  75     <para>This generator will only look for root partitions on the
  76     same physical disk the EFI System Partition (ESP) is located on.
  77     It will only look for the other partitions on the same physical
  78     disk the root file system is located on. These partitions will not
  79     be searched on systems where the root file system is distributed
  80     on multiple disks, for example via btrfs RAID.</para>
  81
  82     <para><filename>systemd-gpt-auto-generator</filename> is useful
  83     for centralizing file system configuration in the partition table
  84     and making manual configuration in <filename>/etc/fstab</filename>
  85     or suchlike unnecessary.</para>
  86
  87     <para>This generator looks for the partitions based on their
  88     partition type GUID. The following partition type GUIDs are
  89     identified:</para>
  90
  91     <table>
  92       <title>Partition Type GUIDs</title>
  93       <tgroup cols='3' align='left' colsep='1' rowsep='1'>
  94         <colspec colname="guid" />
  95         <colspec colname="name" />
  96         <colspec colname="explanation" />
  97         <thead>
  98           <row>
  99             <entry>Partition Type GUID</entry>
 100             <entry>Name</entry>
 101             <entry>Explanation</entry>
 102           </row>
 103         </thead>
 104         <tbody>
 105           <row>
 106             <entry>44479540-f297-41b2-9af7-d131d5f0458a</entry>
 107             <entry><filename>Root Partition (x86)</filename></entry>
 108             <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>
 109           </row>
 110           <row>
 111             <entry>4f68bce3-e8cd-4db1-96e7-fbcaf984b709</entry>
 112             <entry><filename>Root Partition (x86-64)</filename></entry>
 113             <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>
 114           </row>
 115           <row>
 116             <entry>69dad710-2ce4-4e3c-b16c-21a1d49abed3</entry>
 117             <entry><filename>Root Partition (32-bit ARM)</filename></entry>
 118             <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>
 119           </row>
 120           <row>
 121             <entry>b921b045-1df0-41c3-af44-4c6f280d3fae</entry>
 122             <entry><filename>Root Partition (64-bit ARM)</filename></entry>
 123             <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>
 124           </row>
 125           <row>
 126             <entry>933ac7e1-2eb4-4f13-b844-0e14e2aef915</entry>
 127             <entry>Home Partition</entry>
 128             <entry>The first home partition on the disk the root partition is located on is mounted to <filename>/home</filename>.</entry>
 129           </row>
 130           <row>
 131             <entry>3b8f8425-20e0-4f3b-907f-1a25a76f98e8</entry>
 132             <entry>Server Data Partition</entry>
 133             <entry>The first server data partition on the disk the root partition is located on is mounted to <filename>/srv</filename>.</entry>
 134           </row>
 135           <row>
 136             <entry>0657fd6d-a4ab-43c4-84e5-0933c84b4f4f</entry>
 137             <entry>Swap</entry>
 138             <entry>All swap partitions located on the disk the root partition is located on are enabled.</entry>
 139           </row>
 140         </tbody>
 141       </tgroup>
 142     </table>
 143
 144     <para>The <filename>/home</filename> and <filename>/srv</filename>
 145     partitions may be encrypted in LUKS format. In this case a device
 146     mapper device is set up under the names
 147     <filename>/dev/mapper/home</filename> and
 148     <filename>/dev/mapper/srv</filename>. Note that this might create
 149     conflicts if the same partition is listed in
 150     <filename>/etc/crypttab</filename> with a different device mapper
 151     device name.</para>
 152
 153     <para>Also note that
 154     <citerefentry><refentrytitle>systemd-efi-boot-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 155     will mount the EFI System Partition (ESP) to
 156     <filename>/boot</filename> if not otherwise mounted.</para>
 157
 158     <para>When using this generator in conjunction with btrfs file
 159     systems, make sure to set the correct default subvolumes on them,
 160     using <command>btrfs subvolume set-default</command>.</para>
 161
 162     <para><filename>systemd-gpt-auto-generator</filename> implements
 163     <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
 164   </refsect1>
 165
 166   <refsect1>
 167     <title>See Also</title>
 168     <para>
 169       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 170       <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 171       <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 172       <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 173       <citerefentry><refentrytitle>systemd-efi-boot-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 174       <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 175       <citerefentry project='die-net'><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 176       <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 177       <citerefentry project='man-pages'><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 178     </para>
 179   </refsect1>
 180
 181 </refentry>