Index: nutchez-0.2/src/test/add_hosts
===================================================================
--- nutchez-0.2/src/test/add_hosts	(revision 172)
+++ nutchez-0.2/src/test/add_hosts	(revision 174)
@@ -2,5 +2,5 @@
 # Program:
 #   Add nutch_nodes to /etc/hosts (for nutchez management interface).
-#   $1=/home/nutchuser/nutch_nodes
+#   $1=/home/nutchuser/nutchez/system/nutch_nodes
 #   $2=/etc/hosts
 # Author: 
@@ -38,5 +38,10 @@
 done
 
-# 附加 nutch_nodes 到 /etc/hosts 
-cp -f /etc/hosts /etc/hosts.bak
-cat $1 | grep -v '#' >> $2
+# Backup /etc/hosts
+cp -f "$2" "$2.bak"
+
+# attache nutch_nodes to hosts
+sed -i '/# NutchEz add/d' $2
+echo "# NutchEz add" >>$2
+cat $1 | grep -v '#' >>$2
+