Adds section about adding a volume node for block storage.

fix bug 1007528

Cherry picked from https://review.openstack.org/#/c/28155/

Change-Id: I9fc616a8c702b71608074241589253e6abb7aecd

doc/src/docbkx/openstack-block-storage-admin/add-volume-node.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<section xml:id="add-volume-node" xmlns="http://docbook.org/ns/docbook"
+    xmlns:xi="http://www.w3.org/2001/XInclude" xmlns:xlink="http://www.w3.org/1999/xlink"
+    version="1.0">
+    <title>Adding Block Storage Nodes</title>
+    <para>To offer more storage to your tenant's VMs, add another volume node running cinder services. Install the required packages for cinder. Creat a volume group called cinder-volumes (configurable using the cinder_volume parameter in <filename>cinder.conf</filename>). Configure tgtd with its targets.conf file and start the tgtd service. Connect the node to the cinder database by configuring the <filename>cinder.conf</filename> file with the connection information. Make sure the iscsi_ip_address setting in cinder.conf matches the public IP of the node you're installing, then restart the cinder services. When you issue a <command>cinder-manage host list</command> command you should see the new volume node listed. If not, look at the logs in <filename>/var/log/cinder/volume.log</filename> for issues. </para>
+</section>

doc/src/docbkx/openstack-block-storage-admin/block-storage-overview.xml

@@ -91,6 +91,7 @@
                 get a new disk (usually a /dev/vdX disk) </para>
         </listitem>
     </orderedlist>
+    <xi:include href="add-volume-node.xml"/>
     <xi:include href="troubleshoot-cinder.xml"/>
     <xi:include href="multi_backend.xml"/>
 </section>