Patent ID: 6898669

Claim:
A disk array apparatus including a disk array which is made up of a plurality of disk drives, has a redundancy disk configuration, and is regarded as one logical disk drive by a host computer, said disk array apparatus comprising: an address translation table including address translation information, said address translation information being used for translating a logical address the host computer uses for specifying a valid logical block into a physical address indicating where in the disk array the logical block is stored; means for making a copy of the address translation table before starting a backup operation, which backs up data stored in the disk array in a mass storage device; means for searching for a valid logical address in accordance with the copy of the address translation table; means for reading from the disk array a physical stripe including a data block whose physical address corresponds to the valid logical address searched for by the searching means; data block writing means for writing in the mass storage device a data block corresponding to a valid logical address included in the physical stripe read by the reading means; means for storing control information in a control table, said control information including a logical address of the data block the data block writing means writes in the mass storage device, and a physical address representing a physical position at which the data block is stored in the mass storage device; control information writing means for writing all control information stored in the control table in the mass storage device; means for restoring the control table based on control information written in the mass storage device when a restoration operation is executed, the restoration operation being for restoring data backed up in the mass storage device in the disk array, wherein said restoring means sorts control information included in the restored control table in an order determined by logical addresses included in the control information; backup data reading means for reading data backed up in the mass storage device in an order determined by corresponding logical addresses in accordance with the restored control table in which the control information is sorted; a write buffer which accumulates data to be written in the disk array; and backup data writing means for writing the data the backup data reading means reads from the mass storage device, the data being written in the disk array through the write buffer, said backup data writing means operating each time data read from the mass storage device has been accumulated in the write buffer by a predetermined number of blocks, and writing 1-stripe data, which includes the predetermined number of blocks of data, in the disk array.