diff --git a/src/cli/one_helper.rb b/src/cli/one_helper.rb
index c1df997153..385ff926a6 100644
--- a/src/cli/one_helper.rb
+++ b/src/cli/one_helper.rb
@@ -67,6 +67,13 @@ EOT
         :description => "Describe list columns"
     }
 
+    APPEND = {
+        :name => "append",
+        :short => "-a",
+        :large => "--append",
+        :description => "Append new attributes to the current template"
+    }
+
     # Command line VM template options
     TEMPLATE_NAME_VM={
         :name   => 'name',
@@ -655,22 +662,32 @@ EOT
     end
 
     def OpenNebulaHelper.update_template(id, resource, path=nil, xpath='TEMPLATE')
+        return update_template_helper(false, id, resource, path=nil, xpath='TEMPLATE')
+    end
+
+    def OpenNebulaHelper.append_template(id, resource, path=nil, xpath='TEMPLATE')
+        return update_template_helper(true, id, resource, path=nil, xpath='TEMPLATE')
+    end
+
+    def OpenNebulaHelper.update_template_helper(append, id, resource, path=nil, xpath='TEMPLATE')
         unless path
             require 'tempfile'
 
             tmp  = Tempfile.new(id.to_s)
             path = tmp.path
 
-            rc = resource.info
+            if !append
+                rc = resource.info
 
-            if OpenNebula.is_error?(rc)
-                puts rc.message
-                exit -1
+                if OpenNebula.is_error?(rc)
+                    puts rc.message
+                    exit -1
+                end
+
+                tmp << resource.template_like_str(xpath)
+                tmp.flush
             end
 
-            tmp << resource.template_like_str(xpath)
-            tmp.flush
-
             editor_path = ENV["EDITOR"] ? ENV["EDITOR"] : EDITOR_PATH
             system("#{editor_path} #{path}")
 
diff --git a/src/cli/onecluster b/src/cli/onecluster
index 11ddb04bd9..4e61e09e09 100755
--- a/src/cli/onecluster
+++ b/src/cli/onecluster
@@ -185,10 +185,16 @@ cmd=CommandParser::CmdParser.new(ARGV) do
         be launched to modify the current content.
     EOT
 
-    command :update, update_desc, :clusterid, [:file, nil] do
+    command :update, update_desc, :clusterid, [:file, nil],
+    :options=>OpenNebulaHelper::APPEND do
         helper.perform_action(args[0],options,"modified") do |obj|
-            str = OpenNebulaHelper.update_template(args[0], obj, args[1])
-            obj.update(str)
+            if options[:append]
+                str = OpenNebulaHelper.append_template(args[0], obj, args[1])
+            else
+                str = OpenNebulaHelper.update_template(args[0], obj, args[1])
+            end
+
+            obj.update(str, options[:append])
         end
     end
 end
diff --git a/src/cli/onedatastore b/src/cli/onedatastore
index 5f23224acf..77e4c4b2c2 100755
--- a/src/cli/onedatastore
+++ b/src/cli/onedatastore
@@ -162,10 +162,16 @@ cmd=CommandParser::CmdParser.new(ARGV) do
         be launched to modify the current content.
     EOT
 
-    command :update, update_desc, :datastoreid, [:file, nil] do
+    command :update, update_desc, :datastoreid, [:file, nil],
+    :options=>OpenNebulaHelper::APPEND do
         helper.perform_action(args[0],options,"modified") do |obj|
-            str = OpenNebulaHelper.update_template(args[0], obj, args[1])
-            obj.update(str)
+            if options[:append]
+                str = OpenNebulaHelper.append_template(args[0], obj, args[1])
+            else
+                str = OpenNebulaHelper.update_template(args[0], obj, args[1])
+            end
+
+            obj.update(str, options[:append])
         end
     end
 end
diff --git a/src/cli/onehost b/src/cli/onehost
index b49ad5ed39..9c9a4d9463 100755
--- a/src/cli/onehost
+++ b/src/cli/onehost
@@ -148,10 +148,16 @@ cmd=CommandParser::CmdParser.new(ARGV) do
         be launched to modify the current content.
     EOT
 
-    command :update, update_desc, :hostid, [:file, nil] do
-        helper.perform_action(args[0],options,"updated") do |host|
-            str = OpenNebulaHelper.update_template(args[0], host, args[1])
-            host.update(str)
+    command :update, update_desc, :hostid, [:file, nil],
+    :options=>OpenNebulaHelper::APPEND do
+        helper.perform_action(args[0],options,"updated") do |obj|
+            if options[:append]
+                str = OpenNebulaHelper.append_template(args[0], obj, args[1])
+            else
+                str = OpenNebulaHelper.update_template(args[0], obj, args[1])
+            end
+
+            obj.update(str, options[:append])
         end
     end
 
diff --git a/src/cli/oneimage b/src/cli/oneimage
index 59a19b56c8..838abb9bd4 100755
--- a/src/cli/oneimage
+++ b/src/cli/oneimage
@@ -212,10 +212,16 @@ cmd=CommandParser::CmdParser.new(ARGV) do
         be launched to modify the current content.
     EOT
 
-    command :update, update_desc, :imageid, [:file, nil] do
-        helper.perform_action(args[0],options,"modified") do |image|
-            str = OpenNebulaHelper.update_template(args[0], image, args[1])
-            image.update(str)
+    command :update, update_desc, :imageid, [:file, nil],
+    :options=>OpenNebulaHelper::APPEND do
+        helper.perform_action(args[0],options,"modified") do |obj|
+            if options[:append]
+                str = OpenNebulaHelper.append_template(args[0], obj, args[1])
+            else
+                str = OpenNebulaHelper.update_template(args[0], obj, args[1])
+            end
+
+            obj.update(str, options[:append])
         end
     end
 
diff --git a/src/cli/onetemplate b/src/cli/onetemplate
index db7153058a..e887cf9882 100755
--- a/src/cli/onetemplate
+++ b/src/cli/onetemplate
@@ -259,10 +259,16 @@ cmd=CommandParser::CmdParser.new(ARGV) do
         be launched to modify the current content.
     EOT
 
-    command :update, update_desc, :templateid, [:file, nil] do
-        helper.perform_action(args[0],options,"modified") do |template|
-            str = OpenNebulaHelper.update_template(args[0], template, args[1])
-            template.update(str)
+    command :update, update_desc, :templateid, [:file, nil],
+    :options=>OpenNebulaHelper::APPEND do
+        helper.perform_action(args[0],options,"modified") do |obj|
+            if options[:append]
+                str = OpenNebulaHelper.append_template(args[0], obj, args[1])
+            else
+                str = OpenNebulaHelper.update_template(args[0], obj, args[1])
+            end
+
+            obj.update(str, options[:append])
         end
     end
 
diff --git a/src/cli/oneuser b/src/cli/oneuser
index 1e929d3492..96aa91f0e5 100755
--- a/src/cli/oneuser
+++ b/src/cli/oneuser
@@ -192,10 +192,16 @@ cmd=CommandParser::CmdParser.new(ARGV) do
         be launched to modify the current content.
     EOT
 
-    command :update, update_desc, :userid, [:file, nil] do
-        helper.perform_action(args[0],options,"modified") do |user|
-            str = OpenNebulaHelper.update_template(args[0], user, args[1])
-            user.update(str)
+    command :update, update_desc, :userid, [:file, nil],
+    :options=>OpenNebulaHelper::APPEND do
+        helper.perform_action(args[0],options,"modified") do |obj|
+            if options[:append]
+                str = OpenNebulaHelper.append_template(args[0], obj, args[1])
+            else
+                str = OpenNebulaHelper.update_template(args[0], obj, args[1])
+            end
+
+            obj.update(str, options[:append])
         end
     end
 
diff --git a/src/cli/onevm b/src/cli/onevm
index 1258d8a749..bf6c4dd074 100755
--- a/src/cli/onevm
+++ b/src/cli/onevm
@@ -208,11 +208,16 @@ cmd=CommandParser::CmdParser.new(ARGV) do
         editor will be launched to modify the current content.
     EOT
 
-    command :update, update_desc, :vmid, [:file, nil] do
-        helper.perform_action(args[0],options,"modified") do |vm|
-            str = OpenNebulaHelper.update_template(args[0], vm, args[1],
-                                                   'USER_TEMPLATE')
-            vm.update(str)
+    command :update, update_desc, :vmid, [:file, nil],
+    :options=>OpenNebulaHelper::APPEND do
+        helper.perform_action(args[0],options,"modified") do |obj|
+            if options[:append]
+                str = OpenNebulaHelper.append_template(args[0], obj, args[1], 'USER_TEMPLATE')
+            else
+                str = OpenNebulaHelper.update_template(args[0], obj, args[1], 'USER_TEMPLATE')
+            end
+
+            obj.update(str, options[:append])
         end
     end
 
diff --git a/src/cli/onevnet b/src/cli/onevnet
index 84d64ea7b8..d7e4ce017a 100755
--- a/src/cli/onevnet
+++ b/src/cli/onevnet
@@ -199,10 +199,16 @@ cmd=CommandParser::CmdParser.new(ARGV) do
         be launched to modify the current content.
     EOT
 
-    command :update, update_desc, :vnetid, [:file, nil] do
-        helper.perform_action(args[0],options,"modified") do |vnet|
-            str = OpenNebulaHelper.update_template(args[0], vnet, args[1])
-            vnet.update(str)
+    command :update, update_desc, :vnetid, [:file, nil],
+    :options=>OpenNebulaHelper::APPEND do
+        helper.perform_action(args[0],options,"modified") do |obj|
+            if options[:append]
+                str = OpenNebulaHelper.append_template(args[0], obj, args[1])
+            else
+                str = OpenNebulaHelper.update_template(args[0], obj, args[1])
+            end
+
+            obj.update(str, options[:append])
         end
     end