1. A plurality of storage nodes in a single chassis, comprising: a first plurality of storage nodes configured to communicate together as a first storage cluster; a second plurality of storage nodes configured to communicate together as a second storage cluster; each of the first and second pluralities of storage nodes having nonvolatile solid-state memory for user data storage; and each of the first and second pluralities of storage nodes configured to distribute user data and metadata associated with the user data throughout a respective plurality of storage nodes such that a respective storage cluster maintains ability to read the user data, using erasure coding, despite a loss of one or more of the respective plurality of storage nodes.