can only access db named "test" with mongodb 3.0.1

[makersu]

When I config for db named "test", it's fine.

       location /test/ {
                gridfs test;
        }

But when I config for another db, like

location /mar/ {
                gridfs mar;
        }

The error.log

Mongo connection dropped, could not reconnect, client: 36.229.212.28, server: localhost, request: "GET /mar/5508186498dc9d7884000001 HTTP/1.1", host: "140.123.4.17:3002"

[makersu]

Seems cannot have more then one node of gridfs directive, but still cannot access to mongodb 3.0.1