Fail VM removal on disk removal failures

Prevents bad states where the VM is "removed" but some of its disks
remain due to e.g. stuck watchers.

Rearrange the sequence so it goes stop, delete disks, then delete VM,
and then return a failure if any of the disk(s) fail to remove, allowing
the task to be rerun after fixing the problem.

daemon-common/vm.py

@@ -449,27 +449,29 @@ def remove_vm(zkhandler, domain):
     if current_vm_state != 'stop':
         change_state(zkhandler, dom_uuid, 'stop')
 
-    # Gracefully terminate the class instances
-    change_state(zkhandler, dom_uuid, 'delete')
-
-    # Delete the configurations
-    zkhandler.delete([
-        ('domain', dom_uuid)
-    ])
-
     # Wait for 1 second to allow state to flow to all nodes
     time.sleep(1)
 
     # Remove disks
     for disk in disk_list:
         # vmpool/vmname_volume
-        try:
-            disk_pool, disk_name = disk.split('/')
-            retcode, message = ceph.remove_volume(zkhandler, disk_pool, disk_name)
-        except ValueError:
-            continue
+        disk_pool, disk_name = disk.split('/')
+        retcode, message = ceph.remove_volume(zkhandler, disk_pool, disk_name)
+        if not retcode:
+            return False, message
 
-    return True, 'Removed VM "{}" and disks from the cluster.'.format(domain)
+    # Gracefully terminate the class instances
+    change_state(zkhandler, dom_uuid, 'delete')
+
+    # Wait for 1/2 second to allow state to flow to all nodes
+    time.sleep(0.5)
+
+    # Delete the VM configuration from Zookeeper
+    zkhandler.delete([
+        ('domain', dom_uuid)
+    ])
+
+    return True, 'Removed VM "{}" and its disks from the cluster.'.format(domain)
 
 
 def start_vm(zkhandler, domain):