diff --git a/xCAT-server/lib/xcat/plugins/profilednodes.pm b/xCAT-server/lib/xcat/plugins/profilednodes.pm
index f2325559a..7c0b273bd 100644
--- a/xCAT-server/lib/xcat/plugins/profilednodes.pm
+++ b/xCAT-server/lib/xcat/plugins/profilednodes.pm
@@ -385,6 +385,7 @@ Usage:
             $allmacs{$macstr} = 0;
         }
     }
+    %allmacsupper = ();
     foreach (keys %allmacs){
             $allmacsupper{uc($_)} = 0;
     }
@@ -1117,6 +1118,7 @@ Usage:
             $allmacs{$macstr} = 0;
         }
     }
+    %allmacsupper = ();
     foreach (keys %allmacs){
         $allmacsupper{uc($_)} = 0;
     }
@@ -1518,6 +1520,7 @@ sub findme{
             $allmacs{$macstr} = 0;
         }
     }
+    %allmacsupper = ();
     foreach (keys %allmacs){
         $allmacsupper{uc($_)} = 0;
     }
diff --git a/xCAT-server/share/xcat/install/scripts/post.ubuntu b/xCAT-server/share/xcat/install/scripts/post.ubuntu
index 364d4f198..70583feb4 100644
--- a/xCAT-server/share/xcat/install/scripts/post.ubuntu
+++ b/xCAT-server/share/xcat/install/scripts/post.ubuntu
@@ -28,6 +28,8 @@ done >>/etc/resolv.conf
 #change the soft link /bin/sh to /bin/bash
 ln -sf /bin/bash /bin/sh
 #
+#delete the useless apt repo
+sed -i 's/^deb.*updates.*$/#&/g' /etc/apt/sources.list
 # Run xCAT post install
 #
 export MASTER_IP="#XCATVAR:XCATMASTER#"