diff --git a/delfin/drivers/hpe/hpe_3par/rest_handler.py b/delfin/drivers/hpe/hpe_3par/rest_handler.py
index 2880b2099..8f4e0f1c3 100644
--- a/delfin/drivers/hpe/hpe_3par/rest_handler.py
+++ b/delfin/drivers/hpe/hpe_3par/rest_handler.py
@@ -158,6 +158,8 @@ def login(self):
                               {"url": url, "reason": res.text})
                     if 'invalid username or password' in res.text:
                         raise exception.InvalidUsernameOrPassword()
+                    elif 'maximum number of server connections' in res.text:
+                        raise exception.StorageMaxUserCountException(res.text)
                     else:
                         raise exception.StorageBackendException(
                             six.text_type(res.text))
@@ -165,9 +167,13 @@ def login(self):
                 LOG.error('Login Parameter error')
 
             return access_session
+        except exception.DelfinException as e:
+            err_msg = "Login error: %s" % (e.msg)
+            LOG.error(err_msg)
+            raise e
         except Exception as e:
             LOG.error("Login error: %s", six.text_type(e))
-            raise e
+            raise exception.StorageBackendException(six.text_type(e))
         finally:
             self.session_lock.release()
 
diff --git a/delfin/drivers/hpe/hpe_3par/ssh_handler.py b/delfin/drivers/hpe/hpe_3par/ssh_handler.py
index e650370c5..8bd2aecfe 100644
--- a/delfin/drivers/hpe/hpe_3par/ssh_handler.py
+++ b/delfin/drivers/hpe/hpe_3par/ssh_handler.py
@@ -485,7 +485,7 @@ def exec_command(self, command):
                 raise NotImplementedError(re)
             elif 'Too many local CLI connections' in re:
                 LOG.error("command %s failed: %s" % (command, re))
-                raise exception.StorageBackendException(re)
+                raise exception.StorageMaxUserCountException(re)
         return re
 
     def get_volumes(self):
diff --git a/delfin/drivers/utils/rest_client.py b/delfin/drivers/utils/rest_client.py
index e72868eb6..f0663dee9 100644
--- a/delfin/drivers/utils/rest_client.py
+++ b/delfin/drivers/utils/rest_client.py
@@ -109,7 +109,11 @@ def do_call(self, url, data, method,
                 raise exception.InvalidIpOrPort()
             elif 'Read timed out' in str(err):
                 raise exception.StorageBackendException(six.text_type(err))
+            elif 'ConnectionResetError(10054' in str(err):
+                raise exception.StorageMaxUserCountException(str(err))
+            elif 'maximum number of server connections' in str(err):
+                raise exception.StorageMaxUserCountException(str(err))
             else:
-                raise exception.BadResponse()
+                raise exception.StorageBackendException(str(err))
 
         return res