systemd-stable/man/systemd.snapshot.xml

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<refentry id="systemd.snapshot">
        <refentryinfo>
                <title>systemd.snapshot</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.snapshot</refentrytitle>
                <manvolnum>5</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>systemd.snapshot</refname>
                <refpurpose>Snapshot unit configuration</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <para><filename>systemd.snapshot</filename></para>
        </refsynopsisdiv>

        <refsect1>
                <title>Description</title>

                <para>Snapshot units are not configured via unit
                configuration files. Nonetheless they are named
                similar to filenames. A unit name whose name ends in
                <filename>.snapshot</filename> refers to a dynamic
                snapshot of the systemd runtime state.</para>

                <para>Snapshots are not configured on disk but created
                dynamically via <command>systemctl snapshot</command>
                (see
                <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
                for details) or an equivalent command. When created,
                they will automatically get dependencies on the
                currently activated units. They act as saved
                runtime state of the systemd manager. Later on, the
                user may choose to return to the saved state via
                <command>systemctl isolate</command>. They are
                useful to roll back to a defined state after
                temporarily starting/stopping services or
                similar.</para>
        </refsect1>

        <refsect1>
                  <title>See Also</title>
                  <para>
                          <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                  </para>
        </refsect1>

</refentry>