Patent ID: 7681072

Claim:
In a data storage system that includes a plurality of storage devices, and one or more nodes that access files from the storage devices, wherein a RAID-X format is implemented at a file level within the plurality of storage devices, a method for file reconstruction comprising: (a) in response to a failure that renders inaccessible at least one portion of a storage device, retrieving a map for at least one file having at least one component stored on the at least one portion; wherein the map includes a list of storage devices where components of the at least one file reside; (b) using the map to determine whether a number of lost or damaged components associated with the at least one file exceed a maximum limit beyond which reconstruction of a file stored using the file level implementation of the RAID-X format is not possible; and (c) if the maximum limit for reconstruction of a file stored using the RAID-X format has not been exceeded, reconstructing the at least one file; wherein the data storage system continues to service data storage and access requests, with reconstruction of the at least one file being performed as a background operation, after a number of device failures has occurred which would have exceeded the maximum limit of storage device failures for reconstruction had the file been stored using a volume level implementation of the RAID-X format.