Implemented sto*_ratio tag

cloudcontrol/node/hypervisor/__init__.py

@@ -117,6 +117,8 @@ class Handler(HostHandler):
                 Tag('sto%s_vol' % name,
                     lambda sto: ' '.join(sto.volumes) if sto.volumes else None,
                     5, 5, storage),
+                Tag('sto%s_ratio' % name,
+                    lambda sto: '%0.2f' % (1 - float(sto.available) / sto.capacity), 5, 5, storage),
             ))
 
         # register domains
@@ -163,6 +165,7 @@ class Handler(HostHandler):
                 'sto%s_used' % storage,
                 'sto%s_type' % storage,
                 'sto%s_vol' % storage,
+                'sto%s_ratio' % storage,
             ))
         # unregister sub objects (for the same reason)
         for sub_id in self.tag_db.keys():