Patent ID: 8782364

Claim:
A storage system comprising: a plurality of nodes; a plurality of data elements stored on the plurality of nodes, wherein each data element is a member data element of one of a plurality of layouts, each layout in the plurality of layouts indicating a unique subset of nodes from the plurality of nodes, wherein for each layout in the plurality of layouts, all member data elements of the layout are stored on each node in the unique subset of nodes indicated by the layout and are not stored on any other node in the plurality of nodes so that whenever there is more than one node in the unique subset of nodes indicated by the layout, all member data elements of the layout are replicated on all nodes in the unique subset of nodes indicated by the layout; and, a dependency list that includes every layout that has member data elements, the dependency list being used to determine availability of data elements based on ability to access nodes from the plurality of nodes; wherein the dependency list is a bitset and wherein within each layout, each node is represented by a bit; and, wherein when a first node becomes unavailable a Boolean operation is performed to indicate that within every layout no data on the first node is available.