man/systemd-analyze.xml

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   8   Copyright 2012 Lennart Poettering
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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                 <cmdsynopsis>
  61                         <command>systemd-analyze <arg choice="opt" rep="repeat">OPTIONS</arg> dot </command>
  62                 </cmdsynopsis>
  63         </refsynopsisdiv>
  64
  65         <refsect1>
  66                 <title>Description</title>
  67
  68                 <para><command>systemd-analyze</command> may be used
  69                 to determine system boot-up performance of the current
  70                 boot.</para>
  71
  72                 <para><command>systemd-analyze time</command>
  73                 prints the time spent in the kernel before
  74                 userspace has been reached, the time spent in the
  75                 initial RAM disk (initrd) before normal system
  76                 userspace has been reached and the time normal system
  77                 userspace took to initialize. Note that these
  78                 measurements simply measure the time passed up to the
  79                 point where all system services have been spawned, but
  80                 not necessarily until they fully finished
  81                 initialization or the disk is idle.</para>
  82
  83                 <para><command>systemd-analyze blame</command> prints
  84                 a list of all running units, ordered by the time they
  85                 took to initialize. This information may be used to
  86                 optimize boot-up times. Note that the output might be
  87                 misleading as the initialization of one service might
  88                 be slow simply because it waits for the initialization
  89                 of another service to complete.</para>
  90
  91                 <para><command>systemd-analyze plot</command> prints
  92                 an SVG graphic detailing which system services have
  93                 been started at what time, highlighting the time they
  94                 spent on initialization.</para>
  95
  96                 <para><command>systemd-analyze dot</command>
  97                 Generate textual dependency graph description in dot
  98                 format for further processing with the GraphViz
  99                 <citerefentry><refentrytitle>dot</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 100                 tool. Use a command line like <command>systemd-analyze
 101                 dot | dot -Tsvg > systemd.svg</command> to generate
 102                 a graphical dependency tree. Unless
 103                 <option>--order</option> or <option>--require</option>
 104                 is passed the generated graph will show both ordering
 105                 and requirement dependencies.</para>
 106
 107                 <para>If no command is passed <command>systemd-analyze
 108                 time</command> is implied.</para>
 109
 110         </refsect1>
 111
 112         <refsect1>
 113                 <title>Options</title>
 114
 115                 <para>The following options are understood:</para>
 116
 117                 <variablelist>
 118                         <varlistentry>
 119                                 <term><option>-h</option></term>
 120                                 <term><option>--help</option></term>
 121
 122                                 <listitem><para>Prints a short help
 123                                 text and exits.</para></listitem>
 124                         </varlistentry>
 125
 126                         <varlistentry>
 127                                 <term><option>--user</option></term>
 128
 129                                 <listitem><para>Shows performance data
 130                                 of user sessions instead of the system
 131                                 manager.</para></listitem>
 132                         </varlistentry>
 133
 134                         <varlistentry>
 135                                 <term><option>--order</option></term>
 136                                 <term><option>--require</option></term>
 137
 138                                 <listitem><para>When used in
 139                                 conjunction with the
 140                                 <command>dot</command> command (see
 141                                 above), selects which dependencies are
 142                                 shown in the dependency graph. If
 143                                 <option>--order</option> is passed
 144                                 only dependencies of type
 145                                 <varname>After=</varname> or
 146                                 <varname>Before=</varname> are
 147                                 shown. If <option>--require</option>
 148                                 is passed only dependencies of type
 149                                 <varname>Requires=</varname>,
 150                                 <varname>RequiresOverridable=</varname>,
 151                                 <varname>Requisite=</varname>,
 152                                 <varname>RequisiteOverridable=</varname>,
 153                                 <varname>Wants=</varname> and
 154                                 <varname>Conflicts=</varname> are
 155                                 shown. If neither is passed, shows
 156                                 dependencies of all these
 157                                 types.</para></listitem>
 158                         </varlistentry>
 159                 </variablelist>
 160
 161         </refsect1>
 162
 163         <refsect1>
 164                 <title>Exit status</title>
 165
 166                 <para>On success 0 is returned, a non-zero failure
 167                 code otherwise.</para>
 168         </refsect1>
 169
 170         <refsect1>
 171                 <title>See Also</title>
 172                 <para>
 173                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 174                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 175                 </para>
 176         </refsect1>
 177
 178 </refentry>