Index: drbl-virt/sbin/functions_drbl_virt
===================================================================
--- drbl-virt/sbin/functions_drbl_virt	(revision 189)
+++ drbl-virt/sbin/functions_drbl_virt	(revision 190)
@@ -327,26 +327,28 @@
 
 function delete_duplicating_MAC(){
-# backup
 drbl_mac_file="/etc/drbl/macadr-$eth.txt"
-cp $drbl_mac_file $drbl_mac_file.$(date +%Y-%m-%d-%H-%M-%S).drbl-virt_bak 
-
-read -p "debug $VM_MACs"
-# Delete duplating VM MAC
-for vm_mac in $(echo $VM_MACs)
-do
-    vm_mac_lines=$(cat -n $drbl_mac_file | grep $vm_mac | awk '{print $1}' )
-    read -p "DEBUG vm_mac_lines $vm_mac_lines"
-    # no duplicated vlaue, doesn't do it
-    if [ -n "$vm_mac_lines" ]; then
-        vm_mac_count=$(echo $vm_mac_lines | wc -w)
-        read -p "de vm_mac_count $vm_mac_count"
-        for (( i=1 ; i<=${vm_mac_count} ; i++ ))
-        do
-            del_line=$(echo $vm_mac_lines | cut -d " " -f${i})
-            sed -i "${del_line}d" $drbl_mac_file
-        done
-        bash
-    fi
-done
+# if macadr-ethX.txt.drbl-virt_bak already have, backup it 
+# else cp default backup
+if [ -e $drbl_mac_file.drbl-virt_bak ]; then
+    cp $drbl_mac_file $drbl_mac_file.$(date +%Y-%m-%d-%H-%M-%S).drbl-virt_bak
+    cp -f $drbl_mac_file.drbl-virt_bak $drbl_mac_file
+else 
+    cp $drbl_mac_file $drbl_mac_file.drbl-virt_bak
+fi
+
+    # Delete duplating VM MAC
+    for vm_mac in $(echo $VM_MACs)
+    do
+        vm_mac_lines=$(cat -n $drbl_mac_file | grep $vm_mac | awk '{print $1}' )
+        # no duplicated vlaue, doesn't do it
+        if [ -n "$vm_mac_lines" ]; then
+            vm_mac_count=$(echo $vm_mac_lines | wc -w)
+            for (( i=1 ; i<=${vm_mac_count} ; i++ ))
+            do
+                del_line=$(echo $vm_mac_lines | cut -d " " -f${i})
+                sed -i "${del_line}d" $drbl_mac_file
+            done
+        fi
+    done
 }