Patent ID: 7788303
Filing Date: 2010-08-31
Classification: G06F

Abstract:
1. A method for identifying selected attributes in files stored in a distributed file system, the method comprising: providing a plurality of nodes in a network, wherein each node comprises: instructing, by the processor of the respective node, each of the nodes that locally stores metadata data blocks to determine each memory location where a metadata data block is locally stored using the respective node's metadata map data structure, read the respective metadata data blocks, and search the locally stored metadata data blocks for files which include data blocks stored on a particular node that is unavailable such that one or more of the nodes performs at least a portion of the search in parallel with at least a portion of the search of one or more of the other nodes; receiving from the nodes that store metadata data blocks, file identifiers related to files that include data blocks stored on the node that is unavailable; accessing the metadata data blocks corresponding to one of the file identifiers to determine the location of at least one accessible content data block and at least one accessible parity data block corresponding to one of the files that include data blocks stored on an unavailable node; reading the at least one accessible content data block and the at least one accessible parity data block from their respective locations in the memory devices of available nodes; and processing the at least one accessible content data block and the at least one accessible parity data block to generate recovered data blocks corresponding to the one or more data blocks stored on the unavailable node, wherein processing the at least one accessible content data block and the at least one accessible parity data block comprises performing an exclusive or (XOR) operation on the at least one accessible content data block and the at least one accessible parity data block.