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systemd/man/systemd-analyze.xml
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<?xml version='1.0'?> <!--*-nxml-*-->
<!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>
<author>
<contrib>Developer</contrib>
<firstname>Harald</firstname>
<surname>Hoyer</surname>
<email>harald@redhat.com</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</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
<arg>time</arg>
</cmdsynopsis>
<cmdsynopsis>
<command>systemd-analyze</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
<arg choice="plain">blame</arg>
</cmdsynopsis>
<cmdsynopsis>
<command>systemd-analyze</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
<arg choice="plain">critical-chain</arg>
<arg choice="opt" rep="repeat"><replaceable>UNIT</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>systemd-analyze</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
<arg choice="plain">plot</arg>
<arg choice="opt">&gt; file.svg</arg>
</cmdsynopsis>
<cmdsynopsis>
<command>systemd-analyze</command>
<arg choice="opt" rep="repeat">OPTIONS</arg>
<arg choice="plain">dot</arg>
<arg choice="opt" rep="repeat"><replaceable>PATTERN</replaceable></arg>
</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 critical-chain [<replaceable>UNIT...</replaceable>]</command>
prints a tree of the time-critical chain of units
(for each of the specified <replaceable>UNIT</replaceable>s
or for the default target otherwise).
The time after the unit is active or started is printed
after the "@" character. The time the unit takes to
start is printed after the "+" character.
Note that the output might be misleading as the
initialization of one service might depend on socket
activation and because of the parallel execution
of units.</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><command>systemd-analyze dot</command> Generate
textual dependency graph description in dot format for
further processing with the GraphViz
<citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
tool. Use a command line like <command>systemd-analyze
dot | dot -Tsvg > systemd.svg</command> to generate a
graphical dependency tree. Unless
<option>--order</option> or <option>--require</option>
is passed, the generated graph will show both ordering
and requirement dependencies. Optional pattern
globbing style specifications
(e.g. <filename>*.target</filename>) may be given at
the end. A unit dependency is included in the graph if
any of these patterns match either the origin or
destination node.</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>
<varlistentry>
<term><option>--order</option></term>
<term><option>--require</option></term>
<listitem><para>When used in
conjunction with the
<command>dot</command> command (see
above), selects which dependencies are
shown in the dependency graph. If
<option>--order</option> is passed
only dependencies of type
<varname>After=</varname> or
<varname>Before=</varname> are
shown. If <option>--require</option>
is passed only dependencies of type
<varname>Requires=</varname>,
<varname>RequiresOverridable=</varname>,
<varname>Requisite=</varname>,
<varname>RequisiteOverridable=</varname>,
<varname>Wants=</varname> and
<varname>Conflicts=</varname> are
shown. If neither is passed, this shows
dependencies of all these
types.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--from-pattern=</option></term>
<term><option>--to-pattern=</option></term>
<listitem><para>When used in
conjunction with the
<command>dot</command> command (see
above), this selects which relationships
are shown in the dependency graph.
They both require
<citerefentry><refentrytitle>glob</refentrytitle><manvolnum>7</manvolnum></citerefentry>
patterns as arguments, which are
matched against left-hand and
right-hand, respectively, nodes of a
relationship. Each of these can be
used more than once, which means a
unit name must match one of the given
values.</para></listitem>
</varlistentry>
<varlistentry>
<term><option>--fuzz=</option><replaceable>timespan</replaceable></term>
<listitem><para>When used in conjunction
with the <command>critical-chain</command>
command (see above), also show units, which
finished <replaceable>timespan</replaceable> earlier, than the
latest unit in the same level. The unit of
<replaceable>timespan</replaceable> is seconds
unless specified with a different unit,
e.g. "50ms".</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>Examples</title>
<para>This plots all dependencies of any unit whose
name starts with <literal>avahi-daemon.</literal>:</para>
<programlisting>$ systemd-analyze dot 'avahi-daemon.*' | dot -Tsvg > avahi.svg
$ eog avahi.svg</programlisting>
<para>This plots the dependencies between all known target units:</para>
<programlisting>systemd-analyze dot --to-pattern='*.target' --from-patter='*.target' | dot -Tsvg > targets.svg
$ eog targets.svg</programlisting>
</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>