Patent ID: 6237068
Filing Date: 2001-05-22
Classification: H04L

Abstract:
A distributed processing system comprising:multiple processors, one processor comprising a client node and one or more other processors each comprising a server node;each server node laving at least one storage tape associated therewith;means for writing blocks of data from a client process of said client node to a first storage tape of a first server node of the distributed processing system, wherein said writing continues until a physical end of storage is reached for the first storage tape, said physical end of storage being reached without size of said first storage tape having been predetermined;means for switching writing blocks of data from said client node to a second storage tape of a second server node of the distributed processing system when said physical end of storage is reached for said first storage tape, wherein said means for switching accomplishes said switching writing transparent to said client process of said client node;wherein said means for writing blocks of data from said client process of the client node to said first storage tape or to said second storage tape comprises means for writing said blocks of data using a write-behind operation wherein said first server node and said second server node periodically notify the client node whether previously received blocks of data have been correctly written to the first storage tape or the second storage tape, respectively;wherein said means for switching writing blocks of data to said second storage tape of said second server node comprises means for accomplishing said switching writing blocks of data without toss of data to be stared by said client process, and wherein said system further comprises means for detecting said physical end of storage of said first storage tape when writing blocks of data thereto, and means for buffering at said first server node unwritten blocks of data received subsequent to said detecting of said physical end of storage of said first storage tape, said unwritten blocks of data being buffered for return to said client node; andfurther comprising means for returning said buffered blocks of data from the first server node to the client node after notifying the client node that said physical end of storage of the first storage tape has been reached.