in the file system hierarchy, a dependency between both
units is created automatically.</para>
- <para>Mount points created at runtime independent on
- unit files or <filename>/etc/fstab</filename> will be
+ <para>Mount points created at runtime (independently of
+ unit files or <filename>/etc/fstab</filename>) will be
monitored by systemd and appear like any other mount
unit in systemd.</para>
+
+ <para>Some file systems have special semantics as API
+ file systems for kernel-to-userspace and
+ userspace-to-userpace interfaces. Some of them may not
+ be changed via mount units, and cannot be disabled.
+ For a longer discussion see <ulink
+ url="http://www.freedesktop.org/wiki/Software/systemd/APIFileSystems">API
+ File Systems</ulink>.</para>
</refsect1>
<refsect1>
<literal>h</literal>, <literal>ms</literal>.</para>
<para>If a mount point is configured in both
- <filename>/etc/fstab</filename> and a unit file, the
- configuration in the latter takes precedence.</para>
+ <filename>/etc/fstab</filename> and a unit file that
+ is stored below <filename>/usr</filename> the former
+ will take precedence. If the unit file is stored below
+ <filename>/etc</filename> it will take
+ precedence. This means: native unit files take
+ precedence over traditional configuration files, but
+ this is superseded by the rule that configuration in
+ <filename>/etc</filename> will always take precedence
+ over configuration in
+ <filename>/usr</filename>.</para>
</refsect1>
<refsect1>
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
</para>
</refsect1>