man: write man page for systemd-analyze

[thirdparty/systemd.git] / man / systemd-analyze.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">

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<refentry id="systemd-analyze">

        <refentryinfo>
                <title>systemd-analyze</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-analyze</refentrytitle>
                <manvolnum>1</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>systemd-analyze</refname>
                <refpurpose>Analyze system boot-up performance</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <cmdsynopsis>
                        <command>systemd-analyze <arg choice="opt" rep="repeat">OPTIONS</arg> time</command>
                </cmdsynopsis>
                <cmdsynopsis>
                        <command>systemd-analyze <arg choice="opt" rep="repeat">OPTIONS</arg> blame </command>
                </cmdsynopsis>
                <cmdsynopsis>
                        <command>systemd-analyze <arg choice="opt" rep="repeat">OPTIONS</arg> plot <arg choice="opt">&gt; file.svg</arg></command>
                </cmdsynopsis>
        </refsynopsisdiv>

        <refsect1>
                <title>Description</title>

                <para><command>systemd-analyze</command> may be used
                to determine system boot-up performance of the current
                boot.</para>

                <para><command>systemd-analyze time</command>
                prints the time spent in the kernel before
                userspace has been reached, the time spent in the
                initial RAM disk (initrd) before normal system
                userspace has been reached and the time normal system
                userspace took to initialize. Note that these
                measurements simply measure the time passed up to the
                point where all system services have been spawned, but
                not necessarily until they fully finished
                initialization or the disk is idle.</para>

                <para><command>systemd-analyze blame</command> prints
                a list of all running units, ordered by the time they
                took to initialize. This information may be used to
                optimize boot-up times. Note that the output might be
                misleading as the initialization of one service might
                be slow simply because it waits for the initialization
                of another service to complete.</para>

                <para><command>systemd-analyze plot</command> prints
                an SVG graphic detailing which system services have
                been started at what time, highlighting the time they
                spent on initialization.</para>

                <para>If no command is passed <command>systemd-analyze
                time</command> is implied.</para>

        </refsect1>

        <refsect1>
                <title>Options</title>

                <para>The following options are understood:</para>

                <variablelist>
                        <varlistentry>
                                <term><option>--h</option></term>
                                <term><option>--help</option></term>

                                <listitem><para>Prints a short help
                                text and exits.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--user</option></term>

                                <listitem><para>Shows performance data
                                of user sessions instead of the system
                                manager.</para></listitem>
                        </varlistentry>
                </variablelist>

        </refsect1>

        <refsect1>
                <title>Exit status</title>

                <para>On success 0 is returned, a non-zero failure
                code otherwise.</para>
        </refsect1>

        <refsect1>
                <title>See Also</title>
                <para>
                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                </para>
        </refsect1>

</refentry>