diff --git a/releasenotes/notes/Add-volume_size_extend-config--opt-for-volume-tests-041f7d25fc2f3e05.yaml b/releasenotes/notes/Add-volume_size_extend-config--opt-for-volume-tests-041f7d25fc2f3e05.yaml
new file mode 100644
index 0000000..8069bd3
--- /dev/null
+++ b/releasenotes/notes/Add-volume_size_extend-config--opt-for-volume-tests-041f7d25fc2f3e05.yaml
@@ -0,0 +1,10 @@
+---
+features:
+  - |
+    Adding new config option for volume tests which allows to specify the size
+    a volume will be extended by (if a test does extend a volume or needs
+    a new bigger volume). The option is beneficial in case such tests are
+    executed on systems where the chunk size (the minimum size a volume can be
+    extended by) is other than 1 (originally hardcoded in the tests).:
+
+    CONF.volume.volume_size_extend
diff --git a/tempest/api/volume/test_volumes_clone.py b/tempest/api/volume/test_volumes_clone.py
index eb54426..9ca1c5e 100644
--- a/tempest/api/volume/test_volumes_clone.py
+++ b/tempest/api/volume/test_volumes_clone.py
@@ -49,13 +49,14 @@
         # Creates a volume from another volume passing a size different from
         # the source volume.
         src_size = CONF.volume.volume_size
+        extend_size = CONF.volume.volume_size_extend
 
         src_vol = self.create_volume(size=src_size)
         # Destination volume bigger than source
         dst_vol = self.create_volume(source_volid=src_vol['id'],
-                                     size=src_size + 1)
+                                     size=src_size + extend_size)
 
-        self._verify_volume_clone(src_vol, dst_vol, extra_size=1)
+        self._verify_volume_clone(src_vol, dst_vol, extra_size=extend_size)
 
     @decorators.idempotent_id('cbbcd7c6-5a6c-481a-97ac-ca55ab715d16')
     @utils.services('image')
diff --git a/tempest/api/volume/test_volumes_clone_negative.py b/tempest/api/volume/test_volumes_clone_negative.py
index 4bfb166..115465c 100644
--- a/tempest/api/volume/test_volumes_clone_negative.py
+++ b/tempest/api/volume/test_volumes_clone_negative.py
@@ -36,11 +36,11 @@
         """Test cloning a volume with decreasing size will fail"""
         # Creates a volume from another volume passing a size different from
         # the source volume.
-        src_size = CONF.volume.volume_size + 1
+        src_size = CONF.volume.volume_size + CONF.volume.volume_size_extend
         src_vol = self.create_volume(size=src_size)
 
         # Destination volume smaller than source
         self.assertRaises(exceptions.BadRequest,
                           self.volumes_client.create_volume,
-                          size=src_size - 1,
+                          size=src_size - CONF.volume.volume_size_extend,
                           source_volid=src_vol['id'])
diff --git a/tempest/api/volume/test_volumes_negative.py b/tempest/api/volume/test_volumes_negative.py
index 35dd0ca..554fc6a 100644
--- a/tempest/api/volume/test_volumes_negative.py
+++ b/tempest/api/volume/test_volumes_negative.py
@@ -45,7 +45,7 @@
             container_format=CONF.image.container_formats[0],
             disk_format=CONF.image.disk_formats[0],
             visibility='private',
-            min_disk=CONF.volume.volume_size + 1)
+            min_disk=CONF.volume.volume_size + CONF.volume.volume_size_extend)
         self.addCleanup(test_utils.call_and_ignore_notfound_exc,
                         self.images_client.delete_image, image['id'])
 
@@ -223,7 +223,7 @@
     @decorators.idempotent_id('8f05a943-013c-4063-ac71-7baf561e82eb')
     def test_volume_extend_with_nonexistent_volume_id(self):
         """Test extending non existent volume should fail"""
-        extend_size = self.volume['size'] + 1
+        extend_size = self.volume['size'] + CONF.volume.volume_size_extend
         self.assertRaises(lib_exc.NotFound, self.volumes_client.extend_volume,
                           data_utils.rand_uuid(), new_size=extend_size)
 
@@ -231,7 +231,7 @@
     @decorators.idempotent_id('aff8ba64-6d6f-4f2e-bc33-41a08ee9f115')
     def test_volume_extend_without_passing_volume_id(self):
         """Test extending volume without passing volume id should fail"""
-        extend_size = self.volume['size'] + 1
+        extend_size = self.volume['size'] + CONF.volume.volume_size_extend
         self.assertRaises(lib_exc.NotFound, self.volumes_client.extend_volume,
                           None, new_size=extend_size)
 
diff --git a/tempest/config.py b/tempest/config.py
index c409db6..6715a00 100644
--- a/tempest/config.py
+++ b/tempest/config.py
@@ -1000,6 +1000,11 @@
     cfg.IntOpt('volume_size',
                default=1,
                help='Default size in GB for volumes created by volumes tests'),
+    cfg.IntOpt('volume_size_extend',
+               default=1,
+               help="Size in GB a volume is extended by - if a test "
+                    "extends a volume, the size of the new volume will be "
+                    "volume_size + volume_size_extend."),
     cfg.ListOpt('manage_volume_ref',
                 default=['source-name', 'volume-%s'],
                 help="A reference to existing volume for volume manage. "