to them.</para>
</refsect1>
+ <refsect1>
+ <title>Initrd System Manager Bootup</title>
+ <para>The default target in the initrd is the initrd-fs.target. The bootup process is
+ identical to the System Manager Bootup until it reaches basic.target. From there,
+ systemd approaches the special initrd.target. If the root device can be mounted at
+ /sysroot, the sysroot.mount unit becomes active and the initrd-root-fs.target is
+ reached.
+ The initrd-parse-etc.service scans /sysroot/etc/fstab for a possible /usr mountpoint
+ and additional entries marked with the <emphasis>x-initrd.mount</emphasis> option.
+ All entries found are mounted below /sysroot, and the initrd-fs.target is reached.
+ The initrd-cleanup.service isolates to the initrd-switch-root.target, where cleanup
+ services can run. As the very last step, the initrd-switch-root.service is activated,
+ which will cause the system to switch its root to /sysroot.
+ </para>
+
+<programlisting>
+ (identical to System Manager Bootup)
+ :
+ :
+ v
+ basic.target
+ | emergency.service
+ ______________________/| |
+ / | v
+ | sysroot.mount <emphasis>emergency.target</emphasis>
+ | |
+ | v
+ | initrd-root-fs.target
+ | |
+ | v
+ | initrd-parse-etc.service
+ (custom initrd services) |
+ | v
+ | (sysroot-usr.mount and
+ | various mounts marked
+ | with fstab option
+ | x-initrd.mount)
+ | |
+ | v
+ | initrd-fs.target
+ | |
+ \______________________ |
+ \|
+ v
+ initrd.target
+ |
+ v
+ initrd-cleanup.service
+ isolates to
+ initrd-switch-root.target
+ |
+ v
+ ______________________/|
+ / |
+ | initrd-udevadm-cleanup-db.service
+ | |
+ (custom initrd services) |
+ | |
+ \______________________ |
+ \|
+ v
+ initrd-switch-root.target
+ |
+ v
+ initrd-switch-root.service
+ |
+ v
+ switch-root
+</programlisting>
+ </refsect1>
+
+
<refsect1>
<title>System Manager Shutdown</title>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>boot</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>dracut</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>