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Index: en_US.ISO8859-1/books/handbook/boot/chapter.xml
===================================================================
--- en_US.ISO8859-1/books/handbook/boot/chapter.xml
+++ en_US.ISO8859-1/books/handbook/boot/chapter.xml
@@ -903,4 +903,57 @@
a module or statically compiled into a custom kernel.</para>
</note>
</sect1>
+
+ <sect1 xml:id="boot-reroot">
+ <title>Root Remount</title>
+
+ <note>
+ <para>Root remount, or <emphasis>reroot</emphasis>,
+ functionality is supported beginning with
+ &os;&nbsp;11.0-RELEASE.</para>
+ </note>
+
+ <para>Mounting the root filesystem sometimes requires additional
+ steps which can only be done from an already-working userspace.
+ One example of this is booting from an <acronym>iSCSI</acronym>
+ <acronym>LUN</acronym>: setting up an <acronym>iSCSI</acronym>
+ session requires the presence of &man.iscsid.8; and
+ &man.iscsictl.8;, which are not available at boot. This
+ presents a chicken and egg problem. The solution is to boot
+ with a temporary root filesystem on a memory disk image
+ preloaded by &man.loader.8;, set up the kernel state as
+ necessary, replace the temporary root file system with the
+ proper one, and then continue booting as usual.</para>
+
+ <para>The first step is to create a temporary root
+ filesystem:</para>
+
+ <screen><userinput>makefs /boot/reroot.img /usr/share/examples/reroot/manifest</userinput></screen>
+
+ <para>Then configure &man.loader.8; to preload the reroot image
+ in <filename>/boot/loader.conf</filename>:</para>
+
+ <screen>reroot_load="YES"
+reroot_type="md_image"
+reroot_name="/boot/reroot.img"</screen>
+
+ <para>The <filename>rc</filename> script contained in the image is
+ configured with &man.kenv.1; variables:
+ <varname>reroot_iface</varname>,
+ <varname>reroot_ifconfig</varname>,
+ <varname>reroot_sh</varname>,
+ <varname>reroot_iscsi_target</varname>,
+ <varname>reroot_iscsi_portal</varname>, and
+ <varname>reroot_mountfrom</varname>.
+ These can be set in <filename>/boot/loader.conf</filename> or
+ manually from the &man.loader.8; prompt.</para>
+
+ <para>As an example, to mount root from an
+ <acronym>iSCSI</acronym> volume:</para>
+
+ <screen>reroot_iface=em0
+reroot_iscsi_target=iqn.2012-06.com.example:target0
+reroot_iscsi_portal=192.168.1.5
+reroot_mountfrom=ufs:/dev/da0</screen>
+ </sect1>
</chapter>

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