diff --git a/weed/iamapi/iamapi_server.go b/weed/iamapi/iamapi_server.go
index cf507ee82..82977458d 100644
--- a/weed/iamapi/iamapi_server.go
+++ b/weed/iamapi/iamapi_server.go
@@ -56,9 +56,16 @@ func NewIamApiServer(router *mux.Router, option *IamServerOption) (iamApiServer
 }
 
 func NewIamApiServerWithStore(router *mux.Router, option *IamServerOption, explicitStore string) (iamApiServer *IamApiServer, err error) {
+	masterClient := wdclient.NewMasterClient(option.GrpcDialOption, "", "iam", "", "", "", *pb.NewServiceDiscoveryFromMap(option.Masters))
+	
+	// Start KeepConnectedToMaster for volume location lookups
+	// IAM config files are typically small and inline, but if they ever have chunks,
+	// ReadEntry→StreamContent needs masterClient for volume lookups
+	go masterClient.KeepConnectedToMaster(context.Background())
+	
 	configure := &IamS3ApiConfigure{
 		option:       option,
-		masterClient: wdclient.NewMasterClient(option.GrpcDialOption, "", "iam", "", "", "", *pb.NewServiceDiscoveryFromMap(option.Masters)),
+		masterClient: masterClient,
 	}
 
 	s3ApiConfigure = configure
diff --git a/weed/wdclient/filer_client.go b/weed/wdclient/filer_client.go
index 038432d1a..bb2e9e5a4 100644
--- a/weed/wdclient/filer_client.go
+++ b/weed/wdclient/filer_client.go
@@ -156,7 +156,7 @@ func (fc *FilerClient) GetLookupFileIdFunction() LookupFileIdFunctionType {
 }
 
 // isRetryableGrpcError checks if a gRPC error is transient and should be retried
-// 
+//
 // Note on codes.Aborted: While Aborted can indicate application-level conflicts
 // (e.g., transaction failures), in the context of volume location lookups (which
 // are simple read-only operations with no transactions), Aborted is more likely
@@ -166,14 +166,14 @@ func isRetryableGrpcError(err error) bool {
 	if err == nil {
 		return false
 	}
-	
+
 	// Check gRPC status code
 	st, ok := status.FromError(err)
 	if ok {
 		switch st.Code() {
-		case codes.Unavailable:      // Server unavailable (temporary)
+		case codes.Unavailable: // Server unavailable (temporary)
 			return true
-		case codes.DeadlineExceeded:  // Request timeout
+		case codes.DeadlineExceeded: // Request timeout
 			return true
 		case codes.ResourceExhausted: // Rate limited or overloaded
 			return true
@@ -184,7 +184,7 @@ func isRetryableGrpcError(err error) bool {
 			return true
 		}
 	}
-	
+
 	// Fallback to string matching for non-gRPC errors (e.g., network errors)
 	errStr := err.Error()
 	return strings.Contains(errStr, "transport") ||