Patent ID: 8521983

Claim:
A computer-readable, non-transitory recording medium which records a storage management program for managing a data allocation status of a distributed storage system that distributes and allocates a plurality of data blocks having a same content to a plurality of storage nodes connected via a network, the program causing a computer to perform a procedure comprising: designating, from the data blocks having the same content, main-data used as an access destination and sub-data used as a backup, and storing management information that registers the storage nodes as allocation destinations of the respective main-data and sub-data; collecting load information on the storage nodes; detecting as a replacement object a pair of the main-data and the sub-data having the same content based on the management information and the collected load information, the pair of the main-data and the sub-data having a condition such that a load difference between a storage node storing the main-data and a storage node storing the sub-data exceeds a predetermined allowable value; updating the management information so as to replace roles of the main-data and the sub-data between the detected pair of data blocks; and transmitting, upon receiving a request for the management information from an access node, the updated management information to the access node, wherein the access node accesses one of the data blocks stored in a storage node among the storage nodes, and when said one of the data blocks is the sub-data and an access to said one of the data blocks is rejected by the accessed storage node, transmits the request to the computer and accesses another one of the data blocks stored in another storage node among the storage nodes based on the updated management information received in response to the request.