Description
Previously Zeppelin have been loading all the notebooks from storage to memory at the start and wouldn't detect if new notebook folders were manually added into ZEPPELIN_NOTEBOOK_DIR. After https://github.com/apache/incubator-zeppelin/pull/331 in-memory notebooks will be updated on every listing if ZEPPELIN_NOTEBOOK_RELOAD_FROM_STORAGE is true. However this new notebooks will not be synced with secondary storage if one is set ( https://github.com/apache/incubator-zeppelin/pull/123 ).