diff --git a/ironic_python_agent/extensions/standby.py b/ironic_python_agent/extensions/standby.py
index 6e0d82683..31c733262 100644
--- a/ironic_python_agent/extensions/standby.py
+++ b/ironic_python_agent/extensions/standby.py
@@ -154,9 +154,17 @@ def _message_format(msg, image_info, device, partition_uuids):
             result_msg = msg + 'root_uuid={}'
             message = result_msg.format(image_info['id'], device, root_uuid)
     else:
-        root_uuid = disk_utils.get_disk_identifier(device)
-        result_msg = msg + 'root_uuid={}'
-        message = result_msg.format(image_info['id'], device, root_uuid)
+        try:
+            # NOTE(TheJulia): ironic-lib disk_utils.get_disk_identifier
+            # can raise OSError if hexdump is not found.
+            root_uuid = disk_utils.get_disk_identifier(device)
+            result_msg = msg + 'root_uuid={}'
+            message = result_msg.format(image_info['id'], device, root_uuid)
+        except OSError as e:
+            LOG.warning('Failed to call get_disk_identifier: '
+                        'Unable to obtain the root_uuid parameter: '
+                        'The hexdump tool may be missing in IPA: %s', e)
+            message = result_msg.format(image_info['id'], device)
     return message
 
 
diff --git a/ironic_python_agent/tests/unit/extensions/test_standby.py b/ironic_python_agent/tests/unit/extensions/test_standby.py
index 8187bb8fd..149d1adb8 100644
--- a/ironic_python_agent/tests/unit/extensions/test_standby.py
+++ b/ironic_python_agent/tests/unit/extensions/test_standby.py
@@ -887,6 +887,21 @@ class TestStandbyExtension(base.IronicAgentTest):
                         'efi_system_partition_uuid=efi_id')
         self.assertEqual(expected_msg, result_msg)
 
+    @mock.patch('ironic_lib.disk_utils.get_disk_identifier',
+                autospec=True)
+    def test__message_format_whole_disk_missing_oserror(self,
+                                                        ident_mock):
+        ident_mock.side_effect = OSError
+        image_info = _build_fake_image_info()
+        msg = 'image ({}) already present on device {}'
+        device = '/dev/fake'
+        partition_uuids = {}
+        result_msg = standby._message_format(msg, image_info,
+                                             device, partition_uuids)
+        expected_msg = ('image (fake_id) already present on device '
+                        '/dev/fake')
+        self.assertEqual(expected_msg, result_msg)
+
 
 class TestImageDownload(base.IronicAgentTest):