diff options
Diffstat (limited to 'man/systemd-fstab-generator.xml')
| -rw-r--r-- | man/systemd-fstab-generator.xml | 46 |
1 files changed, 43 insertions, 3 deletions
diff --git a/man/systemd-fstab-generator.xml b/man/systemd-fstab-generator.xml index a971cb3675..5f37e9193e 100644 --- a/man/systemd-fstab-generator.xml +++ b/man/systemd-fstab-generator.xml @@ -89,12 +89,13 @@ <listitem><para>Takes a boolean argument. Defaults to <literal>yes</literal>. If <literal>no</literal>, causes the - generator to ignore any mounts or swaps configured in + generator to ignore any mounts or swap devices configured in <filename>/etc/fstab</filename>. <varname>rd.fstab=</varname> - is honored only by initial RAM disk (initrd) while + is honored only by the initial RAM disk (initrd) while <varname>fstab=</varname> is honored by both the main system and the initrd.</para></listitem> </varlistentry> + <varlistentry> <term><varname>root=</varname></term> @@ -102,6 +103,7 @@ initrd. <varname>root=</varname> is honored by the initrd.</para></listitem> </varlistentry> + <varlistentry> <term><varname>rootfstype=</varname></term> @@ -109,6 +111,7 @@ passed to the mount command. <varname>rootfstype=</varname> is honored by the initrd.</para></listitem> </varlistentry> + <varlistentry> <term><varname>rootflags=</varname></term> @@ -116,6 +119,7 @@ use. <varname>rootflags=</varname> is honored by the initrd.</para></listitem> </varlistentry> + <varlistentry> <term><varname>mount.usr=</varname></term> @@ -133,6 +137,7 @@ <para><varname>mount.usr=</varname> is honored by the initrd. </para></listitem> </varlistentry> + <varlistentry> <term><varname>mount.usrfstype=</varname></term> @@ -150,6 +155,7 @@ <para><varname>mount.usrfstype=</varname> is honored by the initrd.</para></listitem> </varlistentry> + <varlistentry> <term><varname>mount.usrflags=</varname></term> @@ -166,6 +172,39 @@ <para><varname>mount.usrflags=</varname> is honored by the initrd.</para></listitem> </varlistentry> + + <varlistentry> + <term><varname>systemd.volatile=</varname></term> + + <listitem><para>Controls whether the system shall boot up in volatile mode. Takes a boolean argument or the + special value <option>state</option>.</para> + + <para>If false (the default), this generator makes no changes to the mount tree and the system is booted up in + normal mode.</para> + + <para>If true the generator ensures + <citerefentry><refentrytitle>systemd-volatile-root.service</refentrytitle><manvolnum>8</manvolnum></citerefentry> + is run as part of the initial RAM disk ("initrd"). This service changes the mount table before transitioning to + the host system, so that a volatile memory file system (<literal>tmpfs</literal>) is used as root directory, + with only <filename>/usr</filename> mounted into it from the configured root file system, in read-only + mode. This way the system operates in fully stateless mode, with all configuration and state reset at boot and + lost at shutdown, as <filename>/etc</filename> and <filename>/var</filename> will be served from the (initially + unpopulated) volatile memory file system.</para> + + <para>If set to <option>state</option> the generator will leave the root + directory mount point unaltered, however will mount a <literal>tmpfs</literal> file system to + <filename>/var</filename>. In this mode the normal system configuration (i.e the contents of + <literal>/etc</literal>) is in effect (and may be modified during system runtime), however the system state + (i.e. the contents of <literal>/var</literal>) is reset at boot and lost at shutdown.</para> + + <para>Note that in none of these modes the root directory, <filename>/etc</filename>, <filename>/var</filename> + or any other resources stored in the root file system are physically removed. It's thus safe to boot a system + that is normally operated in non-volatile mode temporarily into volatile mode, without losing data.</para> + + <para>Note that enabling this setting will only work correctly on operating systems that can boot up with only + <filename>/usr</filename> mounted, and are able to automatically populate <filename>/etc</filename>, and also + <filename>/var</filename> in case of <literal>systemd.volatile=yes</literal>.</para></listitem> + </varlistentry> </variablelist> </refsect1> @@ -176,7 +215,8 @@ <citerefentry project='man-pages'><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>, - <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry> + <citerefentry><refentrytitle>systemd-cryptsetup-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>, + <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry> </para> </refsect1> |