A plurality of storage nodes is provided. The plurality of storage nodes is configured to communicate together as a storage cluster. Each of the plurality of storage nodes includes nonvolatile solid-state memory. The plurality of storage nodes is configured to distribute user data and metadata associated with the user data throughout the plurality of storage nodes such that the plurality of storage nodes maintain the ability to read the user data, using erasure coding, despite a loss of one of the plurality of storage nodes. A chassis enclosing the plurality of storage nodes includes power distribution, a high speed communication bus and the ability to install one or more storage nodes which may use the power distribution and communication bus in some embodiments. A method for accessing user data in a plurality of storage nodes having nonvolatile solid-state memory is also provided.