Merge "Add tip for destroying containers"

doc/source/admin/maintenance-tasks/scale-environment.rst

@@ -362,3 +362,40 @@ If a LVM backed Block Storage host needs to be shut down:
 
       # cat /home/user/running_instances | xargs -n1 nova start
       # cat /home/user/running_instances | xargs -n1 nova show | fgrep vm_state
+
+Destroying Containers
+~~~~~~~~~~~~~~~~~~~~~
+
+#. To destroy a container, execute the following:
+
+  .. code-block:: console
+
+     # cd /opt/openstack-ansible/playbooks
+     # openstack-ansible lxc-containers-destroy --limit <container name|container group>
+
+  .. note::
+
+     You will be asked two questions:
+
+       Are you sure you want to destroy the LXC containers?
+       Are you sure you want to destroy the LXC container data?
+
+       The first will just remove the container but leave the data in the bind mounts and logs.
+       The second will remove the data in the bind mounts and logs too.
+
+.. warning::
+   If you remove the containers and data for the entire galera_server container group you
+   will lose all your databases! Also, if you destroy the first container in many host groups
+   you will lose other important items like certificates, keys, etc. Be sure that you
+   understand what you're doing when using this tool.
+
+#. To create the containers again, execute the following:
+
+   .. code-block:: console
+
+      # cd /opt/openstack-ansible/playbooks
+      # openstack-ansible lxc-containers-destroy --limit lxc_hosts,<container name|container
+        group>
+
+   The lxc_hosts host group must be included as the playbook and roles executed require the
+   use of facts from the hosts.