Patent attributes
A data storage system comprises a primary storage system comprising an array of drives and a storage controller comprising a stack of storage components. A storage component of the stack operates a data redundancy scheme for the primary storage system. The storage controller stores a set of data on the primary storage system, detects a failure on one or more drives and determines a set of addresses defining data that cannot be completely repaired. Starting with the storage component operating the data redundancy scheme, each storage component queries the storage component directly above with the set of addresses for the data that cannot be completely repaired, obtaining, from one or more storage components, the data that cannot be completely repaired. This obtained data is used to repair the data on the primary storage system with the data from the one or more storage components.