diff --git a/ucloud/config.py b/ucloud/config.py
index 7c141a3..a2f523f 100644
--- a/ucloud/config.py
+++ b/ucloud/config.py
@@ -25,13 +25,13 @@ etcd_wrapper_kwargs = {
 
 etcd_client = Etcd3Wrapper(*etcd_wrapper_args, **etcd_wrapper_kwargs)
 
-host_pool = HostPool(etcd_client, env_vars.get('HOST_PREFIX'))
-vm_pool = VmPool(etcd_client, env_vars.get('VM_PREFIX'))
-request_pool = RequestPool(etcd_client, env_vars.get('REQUEST_PREFIX'))
+host_pool = HostPool(etcd_client, env_vars.get('HOST_PREFIX', "hosts"))
+vm_pool = VmPool(etcd_client, env_vars.get('VM_PREFIX', "vms"))
+request_pool = RequestPool(etcd_client, env_vars.get('REQUEST_PREFIX', "requests"))
 
 running_vms = []
 
-__storage_backend = env_vars.get("STORAGE_BACKEND")
+__storage_backend = env_vars.get("STORAGE_BACKEND", "filesystem")
 if __storage_backend == "filesystem":
     image_storage_handler = FileSystemBasedImageStorageHandler(vm_base=env_vars.get("VM_DIR"),
                                                                image_base=env_vars.get("IMAGE_DIR"))