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[elogind.git] / man / systemd-analyze.xml
1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4
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8   Copyright 2012 Lennart Poettering
9
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23
24 <refentry id="systemd-analyze">
25
26         <refentryinfo>
27                 <title>systemd-analyze</title>
28                 <productname>systemd</productname>
29
30                 <authorgroup>
31                         <author>
32                                 <contrib>Developer</contrib>
33                                 <firstname>Lennart</firstname>
34                                 <surname>Poettering</surname>
35                                 <email>lennart@poettering.net</email>
36                         </author>
37                 </authorgroup>
38         </refentryinfo>
39
40         <refmeta>
41                 <refentrytitle>systemd-analyze</refentrytitle>
42                 <manvolnum>1</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>systemd-analyze</refname>
47                 <refpurpose>Analyze system boot-up performance</refpurpose>
48         </refnamediv>
49
50         <refsynopsisdiv>
51                 <cmdsynopsis>
52                         <command>systemd-analyze <arg choice="opt" rep="repeat">OPTIONS</arg> time</command>
53                 </cmdsynopsis>
54                 <cmdsynopsis>
55                         <command>systemd-analyze <arg choice="opt" rep="repeat">OPTIONS</arg> blame </command>
56                 </cmdsynopsis>
57                 <cmdsynopsis>
58                         <command>systemd-analyze <arg choice="opt" rep="repeat">OPTIONS</arg> plot <arg choice="opt">&gt; file.svg</arg></command>
59                 </cmdsynopsis>
60         </refsynopsisdiv>
61
62         <refsect1>
63                 <title>Description</title>
64
65                 <para><command>systemd-analyze</command> may be used
66                 to determine system boot-up performance of the current
67                 boot.</para>
68
69                 <para><command>systemd-analyze time</command>
70                 prints the time spent in the kernel before
71                 userspace has been reached, the time spent in the
72                 initial RAM disk (initrd) before normal system
73                 userspace has been reached and the time normal system
74                 userspace took to initialize. Note that these
75                 measurements simply measure the time passed up to the
76                 point where all system services have been spawned, but
77                 not necessarily until they fully finished
78                 initialization or the disk is idle.</para>
79
80                 <para><command>systemd-analyze blame</command> prints
81                 a list of all running units, ordered by the time they
82                 took to initialize. This information may be used to
83                 optimize boot-up times. Note that the output might be
84                 misleading as the initialization of one service might
85                 be slow simply because it waits for the initialization
86                 of another service to complete.</para>
87
88                 <para><command>systemd-analyze plot</command> prints
89                 an SVG graphic detailing which system services have
90                 been started at what time, highlighting the time they
91                 spent on initialization.</para>
92
93                 <para>If no command is passed <command>systemd-analyze
94                 time</command> is implied.</para>
95
96         </refsect1>
97
98         <refsect1>
99                 <title>Options</title>
100
101                 <para>The following options are understood:</para>
102
103                 <variablelist>
104                         <varlistentry>
105                                 <term><option>-h</option></term>
106                                 <term><option>--help</option></term>
107
108                                 <listitem><para>Prints a short help
109                                 text and exits.</para></listitem>
110                         </varlistentry>
111
112                         <varlistentry>
113                                 <term><option>--user</option></term>
114
115                                 <listitem><para>Shows performance data
116                                 of user sessions instead of the system
117                                 manager.</para></listitem>
118                         </varlistentry>
119                 </variablelist>
120
121         </refsect1>
122
123         <refsect1>
124                 <title>Exit status</title>
125
126                 <para>On success 0 is returned, a non-zero failure
127                 code otherwise.</para>
128         </refsect1>
129
130         <refsect1>
131                 <title>See Also</title>
132                 <para>
133                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
134                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
135                 </para>
136         </refsect1>
137
138 </refentry>