its root directory (as configured with
<option>--directory=</option>), that
is removed immediately when the
- container terminates. May not be
- specified together with
+ container terminates. This option is
+ only supported if the root file system
+ is <literal>btrfs</literal>. May not
+ be specified together with
<option>--image=</option> or
<option>--template=</option>.</para></listitem>
</varlistentry>
<listitem><para>Sets the machine name
for this container. This name may be
- used to identify this container on the
- host, and is used to initialize the
- container's hostname (which the
- container can choose to override,
- however). If not specified, the last
- component of the root directory of the
- container is used.</para></listitem>
+ used to identify this container during
+ its runtime (for example in tools like
+ <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ and similar), and is used to
+ initialize the container's hostname
+ (which the container can choose to
+ override, however). If not specified,
+ the last component of the root
+ directory path of the container is
+ used, possibly suffixed with a random
+ identifier in case
+ <option>--ephemeral</option> mode is
+ selected. If the root directory
+ selected is the host's root directory
+ the host's hostname is used as default
+ instead.</para></listitem>
</varlistentry>
<varlistentry>
at the same location. <literal>try-host</literal>
and <literal>try-guest</literal> do the same
but do not fail if the host does not have
- persistant journalling enabled.
+ persistent journalling enabled.
If <literal>auto</literal> (the default),
and the right subdirectory of
<filename>/var/log/journal</filename>
<example>
<title>Boot a minimal Fedora distribution in a container</title>
- <programlisting># yum -y --releasever=19 --nogpg --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora install systemd passwd yum fedora-release vim-minimal
+ <programlisting># yum -y --releasever=21 --nogpg --installroot=/srv/mycontainer --disablerepo='*' --enablerepo=fedora install systemd passwd yum fedora-release vim-minimal
# systemd-nspawn -bD /srv/mycontainer</programlisting>
<para>This installs a minimal Fedora distribution into
</example>
<example>
- <title>Boot into a <literal>btrfs</literal> snapshot of the host system</title>
+ <title>Boot into an ephemeral <literal>btrfs</literal> snapshot of the host system</title>
- <programlisting># btrfs subvolume snapshot / /.tmp
-# systemd-nspawn --private-network -D /.tmp -b</programlisting>
+ <programlisting># systemd-nspawn -D / -xb</programlisting>
<para>This runs a copy of the host system in a
- <literal>btrfs</literal> snapshot.</para>
+ <literal>btrfs</literal> snapshot which is
+ removed immediately when the container
+ exits. All file system changes made during
+ runtime will be lost on shutdown,
+ hence.</para>
</example>
<example>
<citerefentry project='die-net'><refentrytitle>debootstrap</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry project='archlinux'><refentrytitle>pacman</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>btrfs</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>