Patent ID: 6912614

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: means for storing 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; a write buffer in which data to be written in the disk array is accumulated; first searching means for searching for a valid logical address in accordance with the address translation table, said first searching means operating if one of the disk drives of the disk array fails and the disk array is reconstructed using a spare disk drive in place of the failing disk drive; means for reading from the disk array a physical stripe including the physical block corresponding to the logical block of the valid logical address searched for by the first searching means; second searching means for searching for a valid logical address based on the address translation table from among logical addresses of logical blocks corresponding to physical blocks included in the physical stripe read by the reading means; means for restoring valid data of the failing disk drive and which corresponds to the valid logical address searched for by the second search means, said valid data being restored based on the physical stripe read by the reading means; first writing means for writing data in the write buffer in units of one block, the data written by the first writing means including data which is stored in the failing disk drive and restored by the restoring means, and data which is included in the physical stripe read by the reading means, corresponds to the valid logical address searched for by the second searching means, and is data other than that stored in the failing disk drive; and second writing means for writing 1-stripe data including data corresponding to a predetermined number of blocks, each time the data corresponding to the predetermined number of blocks is accumulated in the write buffer, said 1-stripe data being written in a free area of a new disk array that uses a spare disk drive in place of the failing disk drive, said free area being different from an area where data which is stored in disk drives of the new disk array and which is to be updated is held.