Patent ID: 6499039
Filing Date: 2002-12-24
Classification: G06F,Y10S

Abstract:
A method of operating a data storage system for on-line expansion of a file system so that the file system uses additional data storage added to original data storage of the data storage system, data of the file system residing in the original data storage prior to the expansion, said method comprising the steps of reorganizing at least a portion of the data of the file system by moving some of the data of the file system from the original data storage to the additional data storage so tat the data of the file system is distributed over the original data storage and the additional data storage, and a file of the file system is reorganized by distributing data of the file over the original data storage and the additional data storage so that one portion of the data of the file remains in the original data storage and another portion of the data of the file is moved from we original data storage to the additional data storage, and repetitively updating metadata of the file during the movement of data of the file to permit a host processor to access concurrently the data of the file during the reorganization of the file;wherein data of the file is sequentially striped across the original data storage prior to the expansion, and during the expansion data of the file is sequentially striped across the original data storage and the additional data storage; and wherein an order of striping of data of the file in the original data storage prior to the expansion is not preserved during the striping of data across the original data storage and the additional data storage during the expansion, and the movement of data of the file from the original data storage to the additional data storage is performed up to a pivot point by using temporary storage for the data that is moved, and after the pivot point the movement of data of the file from the original data storage to the additional data storage is performed without using temporary storage for the data that is moved.