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systemd/man/systemd.slice.xml
Lennart Poettering 818bf54632 tree-wide: drop 'This file is part of systemd' blurb
This part of the copyright blurb stems from the GPL use recommendations:

https://www.gnu.org/licenses/gpl-howto.en.html

The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.

hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
2018-06-14 10:20:20 +02:00

129 lines
5.5 KiB
XML

<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
SPDX-License-Identifier: LGPL-2.1+
Copyright 2013 Zbigniew Jędrzejewski-Szmek
-->
<refentry id="systemd.slice">
<refentryinfo>
<title>systemd.slice</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Lennart</firstname>
<surname>Poettering</surname>
<email>lennart@poettering.net</email>
</author>
</authorgroup>
</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>1</manvolnum></citerefentry>
are found in <filename>machine.slice</filename>, and user sessions
handled by
<citerefentry><refentrytitle>systemd-logind</refentrytitle><manvolnum>1</manvolnum></citerefentry>
in <filename>user.slice</filename>. See
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>5</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://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/">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>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>