diff --git a/vectordb_bench/backend/clients/aws_opensearch/aws_opensearch.py b/vectordb_bench/backend/clients/aws_opensearch/aws_opensearch.py
index 03443b255..8d77d263b 100644
--- a/vectordb_bench/backend/clients/aws_opensearch/aws_opensearch.py
+++ b/vectordb_bench/backend/clients/aws_opensearch/aws_opensearch.py
@@ -117,6 +117,7 @@ def _build_vector_field_config(self) -> dict:
                 "data_type": "float",
                 "mode": "on_disk",
                 "compression_level": "32x",
+                "method": method_config,
             }
             log.info("Using on-disk vector configuration with compression_level: 32x")
         else:
@@ -283,13 +284,19 @@ def insert_chunk(client_idx: int, chunk_idx: int):
                     other_data[self.label_col_name] = chunk_labels_data[i]
                 insert_data.append(other_data)
 
-            try:
-                resp = client.bulk(body=insert_data)
-                log.info(f"Client {client_idx} added {len(resp['items'])} documents")
-                return len(chunk_embeddings), None
-            except Exception as e:
-                log.warning(f"Client {client_idx} failed to insert data: {e!s}")
-                return 0, e
+            max_retries = 10
+            for attempt in range(max_retries):
+                try:
+                    client.bulk(body=insert_data)
+                    return len(chunk_embeddings), None
+                except Exception as e:
+                    if "429" in str(e) and attempt < max_retries - 1:
+                        log.warning(f"Client {client_idx} got 429 error, retry {attempt + 1}/{max_retries} after 10s")
+                        time.sleep(10)
+                    else:
+                        log.warning(f"Client {client_idx} failed to insert data: {e!s}")
+                        return 0, e
+            return 0, Exception("Max retries exceeded")
 
         results = []
         with ThreadPoolExecutor(max_workers=len(clients)) as executor:
diff --git a/vectordb_bench/backend/clients/aws_opensearch/config.py b/vectordb_bench/backend/clients/aws_opensearch/config.py
index 327ba83e5..ff87f66bf 100644
--- a/vectordb_bench/backend/clients/aws_opensearch/config.py
+++ b/vectordb_bench/backend/clients/aws_opensearch/config.py
@@ -129,10 +129,6 @@ def index_param(self) -> dict:
         if self.engine == AWSOS_Engine.s3vector:
             return {"engine": "s3vector"}
 
-        # For on-disk mode, return empty dict as no method config is needed
-        if self.on_disk:
-            return {}
-
         parameters = {"ef_construction": self.efConstruction, "m": self.M}
 
         # Add encoder configuration based on quantization type