diff --git a/backend/services/rag/vectorstore.py b/backend/services/rag/vectorstore.py
index e426471..6547279 100644
--- a/backend/services/rag/vectorstore.py
+++ b/backend/services/rag/vectorstore.py
@@ -203,6 +203,9 @@ class MilvusVectorStore(BaseVectorStore):
             "[MILVUS] Insert result: %s",
             insert_result,
         )
+        # Flush to ensure data is persisted to object storage (MinIO) immediately
+        await self.client.flush(collection_name)
+        logger.info("[MILVUS] Flushed collection '%s' to disk", collection_name)
 
     async def search(
         self, collection_name: str, query: str, limit: int = 4, filter: str = ""
diff --git a/docker-compose.yml b/docker-compose.yml
index 0666215..fb82632 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -116,6 +116,12 @@ services:
     environment:
       ETCD_ENDPOINTS: etcd:2379
       MINIO_ADDRESS: minio:9000
+      MINIO_ACCESS_KEY: minioadmin
+      MINIO_SECRET_KEY: minioadmin
+      MINIO_BUCKET_NAME: agent-alpha
+      # Data persistence tuning — flush segments to S3/MinIO every 3s
+      dataCoord_segment_dmlogFileTimeout: "3"
+      dataCoord_segment_flushInterval: "3"
     volumes:
       - milvus_data:/var/lib/milvus
     command: milvus run standalone
@@ -134,6 +140,7 @@ services:
       ETCD_SNAPSHOT_COUNT: "50000"
       ETCD_LISTEN_CLIENT_URLS: "http://0.0.0.0:2379"
       ETCD_ADVERTISE_CLIENT_URLS: "http://0.0.0.0:2379"
+      ETCD_DATA_DIR: /etcd
     volumes:
       - etcd_data:/etcd
     restart: unless-stopped