References: bnc#892003
For very large memory VMs Xen takes a long time scrubbing memory
which causes the libvirt connection to timeout. Upstream was not
interested in making this a preferences option (4/11/2015)
Index: virt-manager-3.3.0/virtManager/connection.py
===================================================================
--- virt-manager-3.3.0.orig/virtManager/connection.py
+++ virt-manager-3.3.0/virtManager/connection.py
@@ -971,7 +971,7 @@ class vmmConnection(vmmGObject):
         self._add_conn_events()
 
         try:
-            self._backend.setKeepAlive(20, 1)
+            self._backend.setKeepAlive(20, 10)
         except Exception as e:
             log.debug("Failed to setKeepAlive: %s", str(e))