aboutsummaryrefslogblamecommitdiffhomepage
path: root/linux/systemd.html
blob: 191b7b3cf490339598f4a611146142c266c1c8ec (plain) (tree)
1
2
3
4
5
6
7
8
9
               
                                                        



                                            

 
                                 
 

                                                                            
                                                   
 
                                               




                                                                     
 

                                                                          
                                                         
 





                                                            
 
 
                                                
                
                                     
                                                                                                             
                 




                                          
                                                                                       
                














                                                                                                 
                


                                                                                 
                                                  

                                          
                                     

                 

                                                                         
                                                             
                
                               
                                                                                  


                                                                                      

                                   
             
                                                           

                                                     


                                                                         




                                                                                           


                                                                          




                                                    
                                                           
                                                           
                                              
                                                                                                                                                                                                  
                                                      
                                



                                                                                                                                                                                                         
                                                                                                                








                                                                                                                                                                                                                       
 
                                                     
 






                                                                                                                       
 


                          

                                                                       
                                                                                                                                                                                            






                                                                                          
 
                                                                                                                   
                        








                                                                                                                   

                                                                                           



                                                       


                                                                                                         
















                                                             






                                                                                                                          
                                                                                                                          






                                                
                                                                                 






                              
                                                                            












                                                                            
                                                                            








                                                                                                              


                                                                                                                                                                                          
 
                                                                                                                                                                                           

                                                                 
 





                                                                       
                                                                                                                                                                           

                                                        
 
                                                                                                                                                                            

                                                         



                  



                
                                              
                 








                                                     

                                  

 
          

           
<!DOCTYPE HTML>
<html lang="en" class="light sidebar-visible" dir="ltr">
    <head>
        <!-- Book generated using mdBook -->
        <meta charset="UTF-8">
        <title>systemd - Notes</title>


        <!-- Custom HTML head -->

        <meta name="description" content="">
        <meta name="viewport" content="width=device-width, initial-scale=1">
        <meta name="theme-color" content="#ffffff">

        <link rel="icon" href="../favicon.svg">
        <link rel="shortcut icon" href="../favicon.png">
        <link rel="stylesheet" href="../css/variables.css">
        <link rel="stylesheet" href="../css/general.css">
        <link rel="stylesheet" href="../css/chrome.css">
        <link rel="stylesheet" href="../css/print.css" media="print">

        <!-- Fonts -->
        <link rel="stylesheet" href="../FontAwesome/css/font-awesome.css">
        <link rel="stylesheet" href="../fonts/fonts.css">

        <!-- Highlight.js Stylesheets -->
        <link rel="stylesheet" href="../highlight.css">
        <link rel="stylesheet" href="../tomorrow-night.css">
        <link rel="stylesheet" href="../ayu-highlight.css">

        <!-- Custom theme stylesheets -->


        <!-- Provide site root to javascript -->
        <script>
            var path_to_root = "../";
            var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
        </script>
        <!-- Start loading toc.js asap -->
        <script src="../toc.js"></script>
    </head>
    <body>
    <div id="body-container">
        <!-- Work around some values being stored in localStorage wrapped in quotes -->
        <script>
            try {
                var theme = localStorage.getItem('mdbook-theme');
                var sidebar = localStorage.getItem('mdbook-sidebar');

                if (theme.startsWith('"') && theme.endsWith('"')) {
                    localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
                }

                if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
                    localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
                }
            } catch (e) { }
        </script>

        <!-- Set the theme before any content is loaded, prevents flash -->
        <script>
            var theme;
            try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
            if (theme === null || theme === undefined) { theme = default_theme; }
            const html = document.documentElement;
            html.classList.remove('light')
            html.classList.add(theme);
            html.classList.add("js");
        </script>

        <input type="checkbox" id="sidebar-toggle-anchor" class="hidden">

        <!-- Hide / unhide sidebar before it is displayed -->
        <script>
            var sidebar = null;
            var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
            if (document.body.clientWidth >= 1080) {
                try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
                sidebar = sidebar || 'visible';
            } else {
                sidebar = 'hidden';
            }
            sidebar_toggle.checked = sidebar === 'visible';
            html.classList.remove('sidebar-visible');
            html.classList.add("sidebar-" + sidebar);
        </script>

        <nav id="sidebar" class="sidebar" aria-label="Table of contents">
            <!-- populated by js -->
            <mdbook-sidebar-scrollbox class="sidebar-scrollbox"></mdbook-sidebar-scrollbox>
            <noscript>
                <iframe class="sidebar-iframe-outer" src="../toc.html"></iframe>
            </noscript>
            <div id="sidebar-resize-handle" class="sidebar-resize-handle">
                <div class="sidebar-resize-indicator"></div>
            </div>
        </nav>

        <div id="page-wrapper" class="page-wrapper">

            <div class="page">
                <div id="menu-bar-hover-placeholder"></div>
                <div id="menu-bar" class="menu-bar sticky">
                    <div class="left-buttons">
                        <label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
                            <i class="fa fa-bars"></i>
                        </label>
                        <button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
                            <i class="fa fa-paint-brush"></i>
                        </button>
                        <ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
                            <li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
                            <li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
                        </ul>
                        <button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
                            <i class="fa fa-search"></i>
                        </button>
                    </div>

                    <h1 class="menu-title">Notes</h1>

                    <div class="right-buttons">
                        <a href="../print.html" title="Print this book" aria-label="Print this book">
                            <i id="print-button" class="fa fa-print"></i>
                        </a>
                        <a href="https://github.com/johannst/notes" title="Git repository" aria-label="Git repository">
                            <i id="git-repository-button" class="fa fa-github"></i>
                        </a>

                    </div>
                </div>

                <div id="search-wrapper" class="hidden">
                    <form id="searchbar-outer" class="searchbar-outer">
                        <input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
                    </form>
                    <div id="searchresults-outer" class="searchresults-outer hidden">
                        <div id="searchresults-header" class="searchresults-header"></div>
                        <ul id="searchresults">
                        </ul>
                    </div>
                </div>

                <!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
                <script>
                    document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
                    document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
                    Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
                        link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
                    });
                </script>

                <div id="content" class="content">
                    <main>
                        <h1 id="systemd"><a class="header" href="#systemd">systemd</a></h1>
<h2 id="systemctl"><a class="header" href="#systemctl">systemctl</a></h2>
<p>Inspect units:</p>
<pre><code class="language-text">systemctl [opts] [cmd]
[opts]
    --user
    --type=TYPE             List only given types eg, service, timer, socket (use --type=help for a list)
    --state=STATE           List only given states eg running, enabled (use --state=help for a list)
    --failed                List only failed services

[cmd]
    list-units &lt;pattern&gt;    List units in memory

    status &lt;unit&gt;           Show runtime status of unit

    start &lt;unit&gt;            Start a unit
    stop &lt;unit&gt;             Stop a unit
    restart &lt;unit&gt;          Restart a unit
    reload &lt;unit&gt;           Reload a unit

    enable &lt;unit&gt;           Enable a unit (persistent)
    disable &lt;unit&gt;          Disable a unit

    cat &lt;unit&gt;      Print unit file
    show &lt;unit&gt;     Show properties of unit
</code></pre>
<h3 id="example-list-failed-units"><a class="header" href="#example-list-failed-units">Example: List failed units</a></h3>
<pre><code class="language-bash"># List all system failed units.
systemctl --failed

# List all user failed units.
systemctl --user --failed
</code></pre>
<h3 id="example-trivial-user-unit"><a class="header" href="#example-trivial-user-unit">Example: Trivial user unit</a></h3>
<pre><code class="language-bash"># Generate unit
mkdir -p ~/.config/systemd/user
echo '[Unit]
Description=Test logger

[Service]
Type=oneshot
ExecStart=logger "Hello from test unit"' &gt; ~/.config/systemd/user/test.service

# Run unit
systemctl --user start test

# See log message
journalctl --user -u test -n 5
</code></pre>
<h2 id="journalctl"><a class="header" href="#journalctl">journalctl</a></h2>
<p>Inspect journal logs:</p>
<pre><code class="language-text">journalctl [opts] [matches]
    --user          Current user journal (system by default)
    -u &lt;unit&gt;       Show logs for specified &lt;unit&gt;
    -n &lt;lines&gt;      Show only last &lt;lines&gt;
    -f              Follow journal
    -g &lt;pattern&gt;    Grep for &lt;pattern&gt;
</code></pre>
<p>Cleanup:</p>
<pre><code class="language-text">journalctl [opts]
    --disk-usage            Show current disk usage
    --vacuum-size=&lt;size&gt;    Reduce journal log to &lt;size&gt; (K/M/G)
</code></pre>
<h2 id="references"><a class="header" href="#references">References</a></h2>
<ul>
<li><a href="https://www.man7.org/linux/man-pages/man5/systemd.unit.5.html">man systemd.unit(5)</a></li>
<li><a href="https://www.man7.org/linux/man-pages/man5/systemd.service.5.html">man systemd.service(5)</a></li>
</ul>

                    </main>

                    <nav class="nav-wrapper" aria-label="Page navigation">
                        <!-- Mobile navigation buttons -->
                            <a rel="prev" href="../linux/index.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
                                <i class="fa fa-angle-left"></i>
                            </a>

                            <a rel="next prefetch" href="../linux/coredump.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
                                <i class="fa fa-angle-right"></i>
                            </a>

                        <div style="clear: both"></div>
                    </nav>
                </div>
            </div>

            <nav class="nav-wide-wrapper" aria-label="Page navigation">
                    <a rel="prev" href="../linux/index.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
                        <i class="fa fa-angle-left"></i>
                    </a>

                    <a rel="next prefetch" href="../linux/coredump.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
                        <i class="fa fa-angle-right"></i>
                    </a>
            </nav>

        </div>




        <script>
            window.playground_copyable = true;
        </script>


        <script src="../elasticlunr.min.js"></script>
        <script src="../mark.min.js"></script>
        <script src="../searcher.js"></script>

        <script src="../clipboard.min.js"></script>
        <script src="../highlight.js"></script>
        <script src="../book.js"></script>

        <!-- Custom JS scripts -->


    </div>
    </body>
</html>