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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">

<refentry id="systemd-gpt-auto-generator">

<refentryinfo>

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

<productname>systemd</productname>

<authorgroup>

<author>

<contrib>Developer</contrib>

<firstname>Lennart</firstname>

<surname>Poettering</surname>

<email>lennart@poettering.net</email>

</author>

</authorgroup>

</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). It implements

the <ulink

url="http://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

automatic 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 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 manual configuration in <filename>/etc/fstab</filename>

or suchlike 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>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>

</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),

mounting it to <filename>/boot</filename> are generated on EFI

systems, where the boot loader communicates the used ESP to the operating

system. Since this generator creates an automount unit, the mount will

only be activated on-demand, when accessed. On systems where

<filename>/boot</filename> 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> 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>