Patent ID: 8166005

Claim:
A storage system comprising: a plurality of servers for interconnection in a data network for servicing client requests for data, the servers storing a nested multilayer directory structure distributed among the servers and indexing the data, wherein the storage system is programmed to store a global index to the nested multilayer directory structure, the global index is an abstract of the nested multilayer directory structure, the global index identifies respective portions of the nested multilayer directory structure that are stored in respective ones of the servers, and the global index identifies paths through the nested multilayer directory structure linking the respective portions of the nested multilayer directory structure, and wherein the storage system is further programmed to perform a top-down search of the nested multilayer directory structure in response to a client request, and upon finding that a portion of the nested multilayer directory structure is offline so as to be inaccessible for searching, to search the global index for portions of the nested multilayer directory structure that are located below the offline portion of the nested multilayer directory structure; wherein each of at least some of the servers is programmed to take over responsibility for maintenance of a respective portion of the nested multilayer directory structure by broadcasting an intention to take over responsibility for maintenance of the respective portion of the nested multilayer directory structure, receiving replies from the other of said at least some of the servers, resolving conflict in the replies, and taking over responsibility for maintenance of the respective portion of the nested multilayer directory structure upon resolving the conflict in favor of said each of at least some of the servers.