diff --git a/lib/cmdlib.py b/lib/cmdlib.py
index 6a975263fb97259bca044ee0f694edff3b1fb237..c9474b0efb984b109c23a4ff42f55dfcef9ef110 100644
--- a/lib/cmdlib.py
+++ b/lib/cmdlib.py
@@ -1423,6 +1423,7 @@ class LUQueryNodes(NoHooksLU):
       "name", "pinst_cnt", "sinst_cnt",
       "pinst_list", "sinst_list",
       "pip", "sip", "tags",
+      "serial_no",
       ])
 
     _CheckOutputFields(static=self.static_fields,
@@ -1528,6 +1529,8 @@ class LUQueryNodes(NoHooksLU):
           val = node.secondary_ip
         elif field == "tags":
           val = list(node.GetTags())
+        elif field == "serial_no":
+          val = node.serial_no
         elif field in self.dynamic_fields:
           val = live_data[node.name].get(field, None)
         else:
@@ -2576,6 +2579,7 @@ class LUQueryInstances(NoHooksLU):
       "hvm_boot_order", "hvm_acpi", "hvm_pae",
       "hvm_cdrom_image_path", "hvm_nic_type",
       "hvm_disk_type", "vnc_bind_address",
+      "serial_no",
       ])
     _CheckOutputFields(static=self.static_fields,
                        dynamic=self.dynamic_fields,
@@ -2705,6 +2709,8 @@ class LUQueryInstances(NoHooksLU):
           val = instance.vcpus
         elif field == "tags":
           val = list(instance.GetTags())
+        elif field == "serial_no":
+          val = instance.serial_no
         elif field in ("network_port", "kernel_path", "initrd_path",
                        "hvm_boot_order", "hvm_acpi", "hvm_pae",
                        "hvm_cdrom_image_path", "hvm_nic_type",
diff --git a/man/gnt-instance.sgml b/man/gnt-instance.sgml
index 15cb4c818f674822383e35870d6bf6628568098c..1dd11525e75c0167f9c92a73ebd9c876edc425bf 100644
--- a/man/gnt-instance.sgml
+++ b/man/gnt-instance.sgml
@@ -612,6 +612,15 @@
                 tags</simpara>
               </listitem>
             </varlistentry>
+            <varlistentry>
+              <term>serial_no</term>
+              <listitem>
+                <simpara>the so called 'serial number' of the
+                instance; this is a numeric field that is incremented
+                each time the instance is modified, and it can be used
+                to detect modifications</simpara>
+              </listitem>
+            </varlistentry>
           </variablelist>
         </para>
 
diff --git a/man/gnt-node.sgml b/man/gnt-node.sgml
index 65b8d81f55343b09f9df5ce2fccb15c8bee8e601..5b1b46871d1af45975699b1c07db5c4993cf63d5 100644
--- a/man/gnt-node.sgml
+++ b/man/gnt-node.sgml
@@ -333,6 +333,15 @@
               tags</simpara>
             </listitem>
           </varlistentry>
+          <varlistentry>
+            <term>serial_no</term>
+            <listitem>
+              <simpara>the so called 'serial number' of the instance;
+              this is a numeric field that is incremented each time
+              the instance is modified, and it can be used to detect
+              modifications</simpara>
+            </listitem>
+          </varlistentry>
         </variablelist>
       </para>
 
diff --git a/scripts/gnt-instance b/scripts/gnt-instance
index 7b8ce9db343e216db7e48476054f6fc6cff82355..3452d08624232343870b8d9ceac99c28c65e3307 100755
--- a/scripts/gnt-instance
+++ b/scripts/gnt-instance
@@ -197,6 +197,7 @@ def ListInstances(opts, args):
       "hvm_nic_type": "HVM_NIC_type",
       "hvm_disk_type": "HVM_disk_type",
       "vnc_bind_address": "VNC_bind_address",
+      "serial_no": "SerialNo",
       }
   else:
     headers = None
@@ -206,7 +207,8 @@ def ListInstances(opts, args):
   else:
     unitfields = None
 
-  numfields = ["admin_ram", "oper_ram", "sda_size", "sdb_size", "vcpus"]
+  numfields = ["admin_ram", "oper_ram", "sda_size", "sdb_size", "vcpus",
+               "serial_no"]
 
   list_type_fields = ("tags",)
   # change raw values to nicer strings
@@ -972,7 +974,8 @@ commands = {
            "Lists the instances and their status. The available fields are"
            " (see the man page for details): status, oper_state, oper_ram,"
            " name, os, pnode, snodes, admin_state, admin_ram, disk_template,"
-           " ip, mac, bridge, sda_size, sdb_size, vcpus. The default field"
+           " ip, mac, bridge, sda_size, sdb_size, vcpus, serial_no."
+           " The default field"
            " list is (in order): %s." % ", ".join(_LIST_DEF_FIELDS),
            ),
   'reinstall': (ReinstallInstance, ARGS_ONE,
diff --git a/scripts/gnt-node b/scripts/gnt-node
index 8acf34a8e64841a45a15380c3f0503b23ab91350..46dc36e8d7d205f62c7cccf0dc48ef41b5909237 100755
--- a/scripts/gnt-node
+++ b/scripts/gnt-node
@@ -91,6 +91,7 @@ def ListNodes(opts, args):
       "bootid": "BootID",
       "ctotal": "CTotal",
       "tags": "Tags",
+      "serial_no": "SerialNo",
       }
   else:
     headers = None
@@ -103,7 +104,7 @@ def ListNodes(opts, args):
   numfields = ["dtotal", "dfree",
                "mtotal", "mnode", "mfree",
                "pinst_cnt", "sinst_cnt",
-               "ctotal"]
+               "ctotal", "serial_no"]
 
   list_type_fields = ("pinst_list", "sinst_list", "tags")
   # change raw values to nicer strings
@@ -344,7 +345,8 @@ commands = {
            "", "Lists the nodes in the cluster. The available fields"
            " are (see the man page for details): name, pinst_cnt, pinst_list,"
            " sinst_cnt, sinst_list, pip, sip, dtotal, dfree, mtotal, mnode,"
-           " mfree, bootid, cpu_count. The default field list is"
+           " mfree, bootid, cpu_count, serial_no."
+           " The default field list is"
            " (in order): %s." % ", ".join(_LIST_DEF_FIELDS),
            ),
   'remove': (RemoveNode, ARGS_ONE, [DEBUG_OPT],