diff --git a/lib/backend.py b/lib/backend.py
index 1d6572908f4f875f7b44700533f3d4839c2682cf..7dc62f5b210d51c64397d4c68946f92c2bef320b 100644
--- a/lib/backend.py
+++ b/lib/backend.py
@@ -451,7 +451,7 @@ def VerifyNode(what, cluster_name):
       what[constants.NV_INSTANCELIST])
 
   if constants.NV_VGLIST in what:
-    result[constants.NV_VGLIST] = ListVolumeGroups()
+    result[constants.NV_VGLIST] = utils.ListVolumeGroups()
 
   if constants.NV_VERSION in what:
     result[constants.NV_VERSION] = (constants.PROTOCOL_VERSION,
@@ -519,7 +519,7 @@ def ListVolumeGroups():
       size of the volume
 
   """
-  return utils.ListVolumeGroups()
+  return True, utils.ListVolumeGroups()
 
 
 def NodeVolumes():
diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index c4a13b9ae0ece0d26703fa6b2f1a9a44983a967a..29b21ad36aec02607b37131b327ef4b6afed26fb 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -1510,11 +1510,13 @@ class LUSetClusterParams(LogicalUnit):
     if self.op.vg_name:
       vglist = self.rpc.call_vg_list(node_list)
       for node in node_list:
-        if vglist[node].failed:
+        msg = vglist[node].RemoteFailMsg()
+        if msg:
           # ignoring down node
-          self.LogWarning("Node %s unreachable/error, ignoring" % node)
+          self.LogWarning("Error while gathering data on node %s"
+                          " (ignoring node): %s", node, msg)
           continue
-        vgstatus = utils.CheckVolumeGroupSize(vglist[node].data,
+        vgstatus = utils.CheckVolumeGroupSize(vglist[node].payload,
                                               self.op.vg_name,
                                               constants.MIN_VG_SIZE)
         if vgstatus:
@@ -5226,7 +5228,10 @@ class LUReplaceDisks(LogicalUnit):
       raise errors.OpExecError("Can't list volume groups on the nodes")
     for node in oth_node, tgt_node:
       res = results[node]
-      if res.failed or not res.data or my_vg not in res.data:
+      msg = res.RemoteFailMsg()
+      if msg:
+        raise errors.OpExecError("Error checking node %s: %s" % (node, msg))
+      if my_vg not in res.payload:
         raise errors.OpExecError("Volume group '%s' not found on %s" %
                                  (my_vg, node))
     for idx, dev in enumerate(instance.disks):
@@ -5422,7 +5427,10 @@ class LUReplaceDisks(LogicalUnit):
     results = self.rpc.call_vg_list([pri_node, new_node])
     for node in pri_node, new_node:
       res = results[node]
-      if res.failed or not res.data or my_vg not in res.data:
+      msg = res.RemoteFailMsg()
+      if msg:
+        raise errors.OpExecError("Error checking node %s: %s" % (node, msg))
+      if my_vg not in res.payload:
         raise errors.OpExecError("Volume group '%s' not found on %s" %
                                  (my_vg, node))
     for idx, dev in enumerate(instance.disks):