Aiming at the problem that when new storage nodes are added to a parallel storage system by using Round-Robin method
the rebalancing operation needs to move a large quantity of data among storage nodes and therefore consume plenty of system resource
a new data layout called ordinal-selection was presented. The data layout of parallel storage system was completed by using rebalancing operations of simulation data repetitiously so as to make the nodes extension of the system more easily. Furthermore
an optimized ordinal-selection layout was also presented to increase the system's parallel degree by changing the data selection rules. The theoretical analysis and experimental results show that for a parallel storage system employing one of these two data layouts
the rebalancing operation can achieve zero ineffectual-move-ratio
therefore the remove of the data can be decreased farthest and the system resource consumption is decreased.