1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
|
<?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>
</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>
|
