MNAIO: Clean up existing data when switching backing store

When switching from LVM to a file backing store, the existing pool
cannot be undefined until any existing VM's and LV's are removed.

This ensures that if this is the case, it will be cleaned up so
that the switch is effortless.

Change-Id: Ie1460b37593306044f0a63f445c3da1987362d34

multi-node-aio/playbooks/setup-host.yml

@@ -261,6 +261,35 @@
         - (default_vm_disk_mode == "file" and _virt_pools.pools.default.format is defined) or
           (default_vm_disk_mode == "lvm" and _virt_pools.pools.default.format is not defined)
       block:
+        - name: Stop running VMs
+          virt:
+            name: "{{ item }}"
+            command: destroy
+          failed_when: false
+          with_items: "{{ _virt_pools.pools.default.volumes }}"
+
+        - name: Delete VM LVs
+          lvol:
+            vg: "{{ default_vm_disk_vg }}"
+            lv: "{{ item }}"
+            state: absent
+            force: yes
+          failed_when: false
+          with_items: "{{ _virt_pools.pools.default.volumes }}"
+
+        - name: Delete VM Disk Images
+          file:
+            path: "{{ _virt_pools.pools.default.path | default('/data/images') }}/{{ item }}.img"
+            state: absent
+          with_items: "{{ _virt_pools.pools.default.volumes }}"
+
+        - name: Undefine the VMs
+          virt:
+            name: "{{ item }}"
+            command: undefine
+          failed_when: false
+          with_items: "{{ _virt_pools.pools.default.volumes }}"
+
         - name: Dismount the mount point if default_vm_disk_mode is 'lvm'
           mount:
             path: /data