US Patent 10423506 Fast rebuild using layered RAID

A System, Computer program product, and computer-executable method of rebuilding a failed data storage device within a storage architecture including a plurality of protection domains including two or more data storage devices, wherein a RAID protection is generated over volumes provided from the plurality of protection domains, the System, Computer program product, and computer-executable method including receiving a notification of a failed data storage device of the data storage devices within a first protection domain of the plurality of protection domains and rebuilding the failed data storage device using reserved data storage within a first data storage device within the first protection domain.