Home > Storage > PowerStore > Databases and Data Analytics > Dell PowerStore: Elastic Stack > Single or multiple-appliance cluster
If horizontal scaling, or scale-out, is required within the PowerStore T model cluster, during the initial configuration, select EDIT APPLIANCE SELECTION (see the following figure). In a multiple-appliance cluster, only the first appliance (primary) can support unified storage. Extra appliances are automatically configured as block-optimized.