US Patent 9430321 Reconstructing data stored across archival data storage devices

Techniques for operating a storage system are disclosed. A read request with an object identifier for a data object is received. A synchronous group of data storage devices across a plurality of enclosures is identified. The synchronous group is associated with the object identifier. A request is sent to the plurality of enclosures to synchronously activate the data storage devices in the synchronous group. After sending the request, data fragments associated with the object identifier are retrieved from the synchronous group of data storage devices. The data fragments are erasure decoded into a contiguous data range to reconstruct the data object.