Patent attributes
Cloud data storage systems, methods, and techniques partition system data symbols into predefined-sized groups and then encode each group to form corresponding parity symbols, encode all data symbols into global redundant symbols, and store each symbol (data, parity, and redundant) in different failure domains in a manner that ensures independence of failures. In several implementations, the resultant cloud-encoded data features both data locality and ability to recover up to a predefined threshold tolerance of simultaneous erasures (unavailable data symbols) without any information loss. In addition, certain implementations also feature the placement of cloud-encoded data in domains (nodes or node groups) to provide similar locality and redundancy features simultaneous with the recovery of an entire domain of data that is unavailable due to software or hardware upgrades or failures.