diff --git a/ironic/drivers/modules/drac/raid.py b/ironic/drivers/modules/drac/raid.py
index 4b54480691..9cc49cb8fb 100644
--- a/ironic/drivers/modules/drac/raid.py
+++ b/ironic/drivers/modules/drac/raid.py
@@ -497,8 +497,14 @@ def _calculate_volume_props(logical_disk, physical_disks, free_space_mb):
 
     disks_per_span = len(selected_disks) / spans_count
 
-    logical_disk['span_depth'] = spans_count
-    logical_disk['span_length'] = disks_per_span
+    # Best practice is to not pass span_length and span_depth when creating a
+    # RAID10.  The iDRAC will dynamically calculate these values using maximum
+    # values obtained from the RAID controller.
+    logical_disk['span_depth'] = None
+    logical_disk['span_length'] = None
+    if logical_disk['raid_level'] != '1+0':
+        logical_disk['span_depth'] = spans_count
+        logical_disk['span_length'] = disks_per_span
 
     max_volume_size_mb = _max_volume_size_mb(
         logical_disk['raid_level'], selected_disks, free_space_mb,
diff --git a/ironic/tests/unit/drivers/modules/drac/test_raid.py b/ironic/tests/unit/drivers/modules/drac/test_raid.py
index a713cccd6a..b86ab5f7d7 100644
--- a/ironic/tests/unit/drivers/modules/drac/test_raid.py
+++ b/ironic/tests/unit/drivers/modules/drac/test_raid.py
@@ -661,6 +661,57 @@ class DracRaidInterfaceTestCase(test_utils.BaseDracTest):
         mock_client = mock.Mock()
         mock_get_drac_client.return_value = mock_client
 
+        self.root_logical_disk = {
+            'size_gb': 100,
+            'raid_level': '5+0',
+            'is_root_volume': True
+        }
+        self.logical_disks = [self.root_logical_disk]
+        self.target_raid_configuration = {'logical_disks': self.logical_disks}
+        self.node.target_raid_config = self.target_raid_configuration
+        self.node.save()
+
+        physical_disks = self._generate_physical_disks()
+        mock_list_physical_disks.return_value = physical_disks
+
+        mock_commit_config.return_value = '42'
+
+        with task_manager.acquire(self.context, self.node.uuid,
+                                  shared=False) as task:
+            task.driver.raid.create_configuration(
+                task, create_root_volume=True, create_nonroot_volumes=True)
+
+            mock_client.create_virtual_disk.assert_called_once_with(
+                'RAID.Integrated.1-1',
+                ['Disk.Bay.0:Enclosure.Internal.0-1:RAID.Integrated.1-1',
+                 'Disk.Bay.1:Enclosure.Internal.0-1:RAID.Integrated.1-1',
+                 'Disk.Bay.2:Enclosure.Internal.0-1:RAID.Integrated.1-1',
+                 'Disk.Bay.3:Enclosure.Internal.0-1:RAID.Integrated.1-1',
+                 'Disk.Bay.4:Enclosure.Internal.0-1:RAID.Integrated.1-1',
+                 'Disk.Bay.5:Enclosure.Internal.0-1:RAID.Integrated.1-1'],
+                '5+0', 102400, None, 3, 2)
+
+            # Commits to the controller
+            mock_commit_config.assert_called_once_with(
+                mock.ANY, raid_controller='RAID.Integrated.1-1', reboot=True)
+
+        self.node.refresh()
+        self.assertEqual(['42'],
+                         self.node.driver_internal_info['raid_config_job_ids'])
+
+    @mock.patch.object(drac_common, 'get_drac_client', spec_set=True,
+                       autospec=True)
+    @mock.patch.object(drac_raid, 'list_physical_disks', autospec=True)
+    @mock.patch.object(drac_job, 'validate_job_queue', spec_set=True,
+                       autospec=True)
+    @mock.patch.object(drac_raid, 'commit_config', spec_set=True,
+                       autospec=True)
+    def test_create_configuration_with_nested_raid_10(
+            self, mock_commit_config, mock_validate_job_queue,
+            mock_list_physical_disks, mock_get_drac_client):
+        mock_client = mock.Mock()
+        mock_get_drac_client.return_value = mock_client
+
         self.root_logical_disk = {
             'size_gb': 100,
             'raid_level': '1+0',
@@ -687,7 +738,7 @@ class DracRaidInterfaceTestCase(test_utils.BaseDracTest):
                  'Disk.Bay.1:Enclosure.Internal.0-1:RAID.Integrated.1-1',
                  'Disk.Bay.2:Enclosure.Internal.0-1:RAID.Integrated.1-1',
                  'Disk.Bay.3:Enclosure.Internal.0-1:RAID.Integrated.1-1'],
-                '1+0', 102400, None, 2, 2)
+                '1+0', 102400, None, None, None)
 
             # Commits to the controller
             mock_commit_config.assert_called_once_with(
diff --git a/releasenotes/notes/drac-fix-raid10-greater-than-16-drives-a4cb107e34371a51.yaml b/releasenotes/notes/drac-fix-raid10-greater-than-16-drives-a4cb107e34371a51.yaml
new file mode 100644
index 0000000000..d34c912040
--- /dev/null
+++ b/releasenotes/notes/drac-fix-raid10-greater-than-16-drives-a4cb107e34371a51.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes an issue where RAID 10 creation fails with greater than 16 drives
+    when using the ``idrac`` hardware type.  See bug `2002771
+    <https://storyboard.openstack.org/#!/story/2002771>`_ for details.