<?xml version='1.0'?> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd"> <!-- SPDX-License-Identifier: LGPL-2.1-or-later --> <refentry id="systemd.slice"> <refentryinfo> <title>systemd.slice</title> <productname>systemd</productname> </refentryinfo> <refmeta> <refentrytitle>systemd.slice</refentrytitle> <manvolnum>5</manvolnum> </refmeta> <refnamediv> <refname>systemd.slice</refname> <refpurpose>Slice unit configuration</refpurpose> </refnamediv> <refsynopsisdiv> <para><filename><replaceable>slice</replaceable>.slice</filename></para> </refsynopsisdiv> <refsect1> <title>Description</title> <para>A unit configuration file whose name ends in <literal>.slice</literal> encodes information about a slice unit. A slice unit is a concept for hierarchically managing resources of a group of processes. This management is performed by creating a node in the Linux Control Group (cgroup) tree. Units that manage processes (primarily scope and service units) may be assigned to a specific slice. For each slice, certain resource limits may be set that apply to all processes of all units contained in that slice. Slices are organized hierarchically in a tree. The name of the slice encodes the location in the tree. The name consists of a dash-separated series of names, which describes the path to the slice from the root slice. The root slice is named <filename>-.slice</filename>. Example: <filename>foo-bar.slice</filename> is a slice that is located within <filename>foo.slice</filename>, which in turn is located in the root slice <filename>-.slice</filename>. </para> <para>Note that slice units cannot be templated, nor is possible to add multiple names to a slice unit by creating additional symlinks to its unit file.</para> <para>By default, service and scope units are placed in <filename>system.slice</filename>, virtual machines and containers registered with <citerefentry><refentrytitle>systemd-machined</refentrytitle><manvolnum>8</manvolnum></citerefentry> are found in <filename>machine.slice</filename>, and user sessions handled by <citerefentry><refentrytitle>systemd-logind</refentrytitle><manvolnum>8</manvolnum></citerefentry> in <filename>user.slice</filename>. See <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry> for more information.</para> <para>See <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for the common options of all unit configuration files. The common configuration items are configured in the generic [Unit] and [Install] sections. The slice specific configuration options are configured in the [Slice] section. Currently, only generic resource control settings as described in <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry> are allowed. </para> <para>See the <ulink url="https://systemd.io/CONTROL_GROUP_INTERFACE">New Control Group Interfaces</ulink> for an introduction on how to make use of slice units from programs.</para> </refsect1> <refsect1> <title>Automatic Dependencies</title> <refsect2> <title>Implicit Dependencies</title> <para>The following dependencies are implicitly added:</para> <itemizedlist> <listitem><para>Slice units automatically gain dependencies of type <varname>After=</varname> and <varname>Requires=</varname> on their immediate parent slice unit.</para></listitem> </itemizedlist> </refsect2> <refsect2> <title>Default Dependencies</title> <para>The following dependencies are added unless <varname>DefaultDependencies=no</varname> is set:</para> <itemizedlist> <listitem><para>Slice units will automatically have dependencies of type <varname>Conflicts=</varname> and <varname>Before=</varname> on <filename>shutdown.target</filename>. These ensure that slice units are removed prior to system shutdown. Only slice units involved with late system shutdown should disable <varname>DefaultDependencies=</varname> option.</para></listitem> </itemizedlist> </refsect2> </refsect1> <refsect1> <title>Options</title> <para>Slice unit files may include [Unit] and [Install] sections, which are described in <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> <para>Slice files may include a [Slice] section. Options that may be used in this section are shared with other unit types. These options are documented in <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> </refsect1> <refsect1> <title>See Also</title> <para><simplelist type="inline"> <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member> <member><citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry></member> <member><citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry></member> <member><citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry></member> <member><citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry></member> <member><citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry></member> <member><citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry></member> </simplelist></para> </refsect1> </refentry>