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| 18 | </style><a href="index.html">Index </a>· | |
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| 20 | <a href="../python-systemd/index.html">Python </a>· | |
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21 | |
| 22 | <span style="float:right">systemd 221</span><hr><div class="refentry"><a name="systemd.swap"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>systemd.swap — Swap unit configuration</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><p><code class="filename"><em class="replaceable"><code>swap</code></em>.swap</code></p></div><div class="refsect1"><a name="idm47667484672848"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p>A unit configuration file whose name ends in | |
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23 | "<code class="literal">.swap</code>" encodes information about a swap device |
| 24 | or file for memory paging controlled and supervised by | |
| 25 | systemd.</p><p>This man page lists the configuration options specific to | |
| 26 | this unit type. See | |
| 27 | <a href="systemd.unit.html"><span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span></a> | |
| 28 | for the common options of all unit configuration files. The common | |
| 29 | configuration items are configured in the generic [Unit] and | |
| 30 | [Install] sections. The swap specific configuration options are | |
| 31 | configured in the [Swap] section.</p><p>Additional options are listed in | |
| 32 | <a href="systemd.exec.html"><span class="citerefentry"><span class="refentrytitle">systemd.exec</span>(5)</span></a>, | |
| 33 | which define the execution environment the | |
| e3bff60a | 34 | <a href="http://man7.org/linux/man-pages/man8/swapon.8.html"><span class="citerefentry"><span class="refentrytitle">swapon</span>(8)</span></a> |
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35 | binary is executed in, and in |
| 36 | <a href="systemd.kill.html"><span class="citerefentry"><span class="refentrytitle">systemd.kill</span>(5)</span></a>, | |
| 37 | which define the way the processes are terminated, and in | |
| 38 | <a href="systemd.resource-control.html"><span class="citerefentry"><span class="refentrytitle">systemd.resource-control</span>(5)</span></a>, | |
| 39 | which configure resource control settings for the processes of the | |
| 40 | service.</p><p>Swap units must be named after the devices | |
| 41 | or files they control. Example: the swap device | |
| 42 | <code class="filename">/dev/sda5</code> must be configured in a | |
| 43 | unit file <code class="filename">dev-sda5.swap</code>. For details about | |
| 44 | the escaping logic used to convert a file system path to a unit | |
| 45 | name, see | |
| 46 | <a href="systemd.unit.html"><span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span></a>.</p><p>All swap units automatically get the appropriate | |
| 47 | dependencies on the devices or on the mount points of the files | |
| 48 | they are activated from.</p><p>Swap units with <code class="varname">DefaultDependencies=</code> | |
| 49 | enabled implicitly acquire a conflicting dependency to | |
| 50 | <code class="filename">umount.target</code> so that they are deactivated at | |
| 86f210e9 | 51 | shutdown.</p></div><div class="refsect1"><a name="idm47667487264368"></a><h2 id="fstab"><code class="filename">fstab</code><a class="headerlink" title="Permalink to this headline" href="#fstab">¶</a></h2><p>Swap units may either be configured via unit files, or via |
| e735f4d4 | 52 | <code class="filename">/etc/fstab</code> (see |
| e3bff60a | 53 | <a href="http://man7.org/linux/man-pages/man5/fstab.5.html"><span class="citerefentry"><span class="refentrytitle">fstab</span>(5)</span></a> |
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54 | for details). Swaps listed in <code class="filename">/etc/fstab</code> will |
| 55 | be converted into native units dynamically at boot and when the | |
| 56 | configuration of the system manager is reloaded. See | |
| 57 | <a href="systemd-fstab-generator.html"><span class="citerefentry"><span class="refentrytitle">systemd-fstab-generator</span>(8)</span></a> | |
| 58 | for details about the conversion.</p><p>If a swap device or file is configured in both | |
| 59 | <code class="filename">/etc/fstab</code> and a unit file, the configuration | |
| 60 | in the latter takes precedence.</p><p>When reading <code class="filename">/etc/fstab</code> a few special | |
| 61 | options are understood by systemd which influence how dependencies | |
| 62 | are created for swap units.</p><div class="variablelist"><dl class="variablelist"><dt id="noauto"><span class="term"><code class="option">noauto</code>, </span><span class="term"><code class="option">auto</code></span><a class="headerlink" title="Permalink to this term" href="#noauto">¶</a></dt><dd><p>With <code class="option">noauto</code> the swap unit | |
| 63 | will not be added as a dependency for | |
| 64 | <code class="filename">swap.target</code>. This means that it will not | |
| 65 | be activated automatically during boot, unless it is pulled in | |
| 66 | by some other unit. Option <code class="option">auto</code> has the | |
| 67 | opposite meaning and is the default.</p></dd><dt id="nofail"><span class="term"><code class="option">nofail</code></span><a class="headerlink" title="Permalink to this term" href="#nofail">¶</a></dt><dd><p>With <code class="option">nofail</code> the swap unit | |
| 68 | will be only wanted, not required by | |
| 69 | <code class="filename">swap.target</code>. This means that the boot | |
| 70 | will continue even if this swap device is not activated | |
| 86f210e9 | 71 | successfully.</p></dd></dl></div></div><div class="refsect1"><a name="idm47667484459632"></a><h2 id="Options">Options<a class="headerlink" title="Permalink to this headline" href="#Options">¶</a></h2><p>Swap files must include a [Swap] section, which carries |
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72 | information about the swap device it supervises. A number of |
| 73 | options that may be used in this section are shared with other | |
| 74 | unit types. These options are documented in | |
| 75 | <a href="systemd.exec.html"><span class="citerefentry"><span class="refentrytitle">systemd.exec</span>(5)</span></a> | |
| 76 | and | |
| 77 | <a href="systemd.kill.html"><span class="citerefentry"><span class="refentrytitle">systemd.kill</span>(5)</span></a>. | |
| 78 | The options specific to the [Swap] section of swap units are the | |
| 79 | following:</p><div class="variablelist"><dl class="variablelist"><dt id="What="><span class="term"><code class="varname">What=</code></span><a class="headerlink" title="Permalink to this term" href="#What=">¶</a></dt><dd><p>Takes an absolute path of a device node or | |
| 80 | file to use for paging. See | |
| e3bff60a | 81 | <a href="http://man7.org/linux/man-pages/man8/swapon.8.html"><span class="citerefentry"><span class="refentrytitle">swapon</span>(8)</span></a> |
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82 | for details. If this refers to a device node, a dependency on |
| 83 | the respective device unit is automatically created. (See | |
| 84 | <a href="systemd.device.html"><span class="citerefentry"><span class="refentrytitle">systemd.device</span>(5)</span></a> | |
| 85 | for more information.) If this refers to a file, a dependency | |
| 86 | on the respective mount unit is automatically created. (See | |
| 87 | <a href="systemd.mount.html"><span class="citerefentry"><span class="refentrytitle">systemd.mount</span>(5)</span></a> | |
| 88 | for more information.) This option is | |
| 89 | mandatory.</p></dd><dt id="Priority="><span class="term"><code class="varname">Priority=</code></span><a class="headerlink" title="Permalink to this term" href="#Priority=">¶</a></dt><dd><p>Swap priority to use when activating the swap | |
| 90 | device or file. This takes an integer. This setting is | |
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91 | optional and ignored when priority is set by <code class="option">pri=</code> in the |
| 92 | <code class="varname">Options=</code> option.</p></dd><dt id="Options="><span class="term"><code class="varname">Options=</code></span><a class="headerlink" title="Permalink to this term" href="#Options=">¶</a></dt><dd><p>May contain an option string for the swap | |
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93 | device. This may be used for controlling discard options among |
| 94 | other functionality, if the swap backing device supports the | |
| 95 | discard or trim operation. (See | |
| e3bff60a | 96 | <a href="http://man7.org/linux/man-pages/man8/swapon.8.html"><span class="citerefentry"><span class="refentrytitle">swapon</span>(8)</span></a> |
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97 | for more information.) </p></dd><dt id="TimeoutSec="><span class="term"><code class="varname">TimeoutSec=</code></span><a class="headerlink" title="Permalink to this term" href="#TimeoutSec=">¶</a></dt><dd><p>Configures the time to wait for the swapon |
| 98 | command to finish. If a command does not exit within the | |
| 99 | configured time, the swap will be considered failed and be | |
| 100 | shut down again. All commands still running will be terminated | |
| 101 | forcibly via <code class="constant">SIGTERM</code>, and after another | |
| 102 | delay of this time with <code class="constant">SIGKILL</code>. (See | |
| 103 | <code class="option">KillMode=</code> in | |
| 104 | <a href="systemd.kill.html"><span class="citerefentry"><span class="refentrytitle">systemd.kill</span>(5)</span></a>.) | |
| 105 | Takes a unit-less value in seconds, or a time span value such | |
| 106 | as "5min 20s". Pass "<code class="literal">0</code>" to disable the | |
| 107 | timeout logic. Defaults to | |
| 108 | <code class="varname">DefaultTimeoutStartSec=</code> from the manager | |
| 109 | configuration file (see | |
| 110 | <a href="systemd-system.conf.html"><span class="citerefentry"><span class="refentrytitle">systemd-system.conf</span>(5)</span></a>). | |
| 111 | </p></dd></dl></div><p>Check | |
| 112 | <a href="systemd.exec.html"><span class="citerefentry"><span class="refentrytitle">systemd.exec</span>(5)</span></a> | |
| 113 | and | |
| 114 | <a href="systemd.kill.html"><span class="citerefentry"><span class="refentrytitle">systemd.kill</span>(5)</span></a> | |
| 86f210e9 | 115 | for more settings.</p></div><div class="refsect1"><a name="idm47667484439264"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p> |
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116 | <a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>, |
| 117 | <a href="systemctl.html"><span class="citerefentry"><span class="refentrytitle">systemctl</span>(1)</span></a>, | |
| 118 | <a href="systemd.unit.html"><span class="citerefentry"><span class="refentrytitle">systemd.unit</span>(5)</span></a>, | |
| 119 | <a href="systemd.exec.html"><span class="citerefentry"><span class="refentrytitle">systemd.exec</span>(5)</span></a>, | |
| 120 | <a href="systemd.kill.html"><span class="citerefentry"><span class="refentrytitle">systemd.kill</span>(5)</span></a>, | |
| 121 | <a href="systemd.resource-control.html"><span class="citerefentry"><span class="refentrytitle">systemd.resource-control</span>(5)</span></a>, | |
| 122 | <a href="systemd.device.html"><span class="citerefentry"><span class="refentrytitle">systemd.device</span>(5)</span></a>, | |
| 123 | <a href="systemd.mount.html"><span class="citerefentry"><span class="refentrytitle">systemd.mount</span>(5)</span></a>, | |
| e3bff60a | 124 | <a href="http://man7.org/linux/man-pages/man8/swapon.8.html"><span class="citerefentry"><span class="refentrytitle">swapon</span>(8)</span></a>, |
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125 | <a href="systemd-fstab-generator.html"><span class="citerefentry"><span class="refentrytitle">systemd-fstab-generator</span>(8)</span></a>, |
| 126 | <a href="systemd.directives.html"><span class="citerefentry"><span class="refentrytitle">systemd.directives</span>(7)</span></a> | |
| 127 | </p></div></div></body></html> |