systemd/man/systemd-gpt-auto-generator.xml

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<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, on systems
                where the units are explicitly configured (for
                example, listed in
                <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>),
                or where the mount points are non-empty.</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>Also note that
                <citerefentry><refentrytitle>systemd-efi-boot-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
                will mount the EFI System Partition (ESP) to
                <filename>/boot</filename> if not otherwise 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 the <ulink
                url="http://www.freedesktop.org/wiki/Software/systemd/Generators">Generator
                Specification</ulink>.</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-efi-boot-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>systemd-cryptsetup@.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>cryptsetup</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
                </para>
        </refsect1>

</refentry>