<title>Description</title>
<para>Preset files may be used to encode policy which
- services shall be enabled by default and which ones
+ units shall be enabled by default and which ones
shall be disabled. They are read by <command>systemctl
preset</command> (for more information see
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>)
set of units to be enabled/disabled even before
installing the actual package.</para>
+ <para>For more information on the preset logic please
+ have a look at the <ulink
+ url="http://freedesktop.org/wiki/Software/systemd/Preset">Presets</ulink>
+ document.</para>
+
<para>It is not recommended to ship preset files
within the respective software packages implementing
- the services, but rather centralize them in a
+ the units, but rather centralize them in a
distribution or spin default policy, which can be
amended by administrator policy.</para>
<para>If no preset files exist, <command>systemctl
preset</command> will enable all units that are
installed by default. If this is not desired and all
- units shall rather be disabled it is necessary to ship
+ units shall rather be disabled, it is necessary to ship
a preset file with a single, catchall
"<filename>disable *</filename>" line. (See example 1,
below.)</para>
by default, <literal>disable</literal> to disable
units by default.</para>
- <para>If multiple lines apply to a unit name the
+ <para>If multiple lines apply to a unit name, the
first matching one takes precedence over all
others.</para>
<filename>/etc/</filename> are reserved for the local
administrator, who may use this logic to override the
preset files installed by vendor packages. All preset
- files are sorted by their filename in alphabetical
+ files are sorted by their filename in lexicographic
order, regardless in which of the directories they
- reside, to guarantee that a specific preset file takes
- precedence over another file with an alphabetically
- earlier name, if both files contain lines that apply
- to the same unit names. It is recommended to prefix
- all file names with two-digit number, to simplify
- ordering.</para>
+ reside. If multiple files specify the same unit name,
+ the entry in the file with the lexicographically earliest
+ name will be applied. It is recommended to prefix all
+ filenames with a two-digit number and a dash, to simplify
+ the ordering of the files.</para>
<para>If the administrator wants to disable a preset
- file supplied by the vendor the recommended way is to
+ file supplied by the vendor, the recommended way is to
place a symlink to <filename>/dev/null</filename> in
<filename>/etc/systemd/system-preset/</filename>
- bearing the same file name.</para>
+ bearing the same filename.</para>
</refsect1>
<refsect1>
<programlisting>disable *</programlisting>
</example>
- <para>This disables all units. Due to the file name
- prefix <literal>99-</literal> it will be read last and
+ <para>This disables all units. Due to the filename
+ prefix <literal>99-</literal>, it will be read last and
hence can easily be overridden by spin or
administrator preset policy or suchlike.</para>
<para>This enables three specific services and
disables all others. This is useful for administrators
to specifically select the units to enable, and
- disable all others. Due to the file name prefix
+ disable all others. Due to the filename prefix
<literal>00-</literal> it will be read early and hence
overrides all other preset policy files.</para>
</refsect1>
~ianmdlvl / elogind.git / blobdiff