Patent ID: 8433947

Claim:
A computer-readable, non-transitory medium storing a data allocation control program for controlling data allocation in a plurality of disk nodes that manage data in storage devices connected thereto, the data allocation control program, when executed by a computer, causing the computer to perform a procedure, the procedure comprising: executing a redundancy restoration procedure by commanding a first disk node that manages redundancy-lost data to create a new copy of the redundancy-lost data, the redundancy-lost data being data stored in a first storage device and lacking a copy thereof; recording, upon receipt of a write error message indicating a write error encountered by a second storage device during the redundancy restoration procedure, an identifier of the second storage device in an error record memory; and identifying the second storage device by consulting the error record memory, selecting data stored in the second storage device as copy target data, and commanding a second disk node managing the second storage device to create a copy of the copy target data in a third storage device having no write error when the third storage device is found to have no such copy of the copy target data.