diff --git a/include/Nebula.h b/include/Nebula.h
index 2dace61736..3acc32a8b5 100644
--- a/include/Nebula.h
+++ b/include/Nebula.h
@@ -217,10 +217,16 @@ public:
     string get_system_ds_path()
     {
         Datastore * ds;
-        string      system_ds_path;
+        string      system_ds_path = "";
 
         ds = dspool->get(DatastorePool::SYSTEM_DS_ID, true);
 
+        if ( ds == 0 )
+        {
+            NebulaLog::log("DaS", Log::ERROR, "Can not get system datastore");
+            return system_ds_path;
+        }
+
         system_ds_path = ds->get_base_path();
 
         ds->unlock();
@@ -235,10 +241,16 @@ public:
     string get_system_ds_tm_mad()
     {
         Datastore * ds;
-        string      tm_mad;
+        string      tm_mad = "";
 
         ds = dspool->get(DatastorePool::SYSTEM_DS_ID, true);
 
+        if ( ds == 0 )
+        {
+            NebulaLog::log("DaS", Log::ERROR, "Can not get system datastore");
+            return tm_mad;
+        }
+
         tm_mad = ds->get_tm_mad();
 
         ds->unlock();
@@ -253,16 +265,23 @@ public:
     string get_system_ds_name()
     {
         Datastore * ds;
-        string      name;
+        string      name = "";
 
         ds = dspool->get(DatastorePool::SYSTEM_DS_ID, true);
 
+        if ( ds == 0 )
+        {
+            NebulaLog::log("DaS", Log::ERROR, "Can not get system datastore");
+            return name;
+        }
+
         name = ds->get_name();
 
         ds->unlock();
 
         return name;
     };
+    
     /**
      *  Returns the path of the log file for a VM, depending where OpenNebula is
      *  installed,
diff --git a/src/vm/History.cc b/src/vm/History.cc
index f06a208ca3..747b057be0 100644
--- a/src/vm/History.cc
+++ b/src/vm/History.cc
@@ -91,7 +91,6 @@ void History::non_persistent_data()
 {
     ostringstream os;
     string        vm_lhome;
-    string        vm_rhome;
     Nebula&       nd = Nebula::instance();
 
     // ----------- Local Locations ------------