A distributed storage system has at least one host and at least one storage node. Hosts write data to and read data from storage devices within the storage nodes. A host upgrade manager (HUM) is installed in at least one of the hosts; a secondary upgrade manager (SUM) is installed in at least one of the nodes; and a primary upgrade manager (PUM) is installed within the distributed storage system itself, for example, in one of the nodes or hosts. Host and node storage system software is upgraded by transferring, via the respective HUM and SUM, upgraded versions of the software from the PUM to at least one host or node detected to be running an outdated version. The host and node storage system software components comprise different, cooperating portions of overall storage management software.