Patent attributes
When a drive in a redundant array of independent disks (RAID) fails, for a first stripe unit stored in the failed drive, a RAID controller obtains from a bitmap a first indicator indicating whether the first stripe unit contains written data, wherein the bitmap contains a plurality of indicators corresponding to stripe units stored in the failed drive, and the first stripe unit belongs to a first stripe stored in the RAID system; if the first indicator indicates that the first stripe unit does not contain written data, write zeros into a first replacement stripe unit in a replacement drive, wherein the first replacement stripe unit replaces the first stripe unit in the first stripe. Without performing XOR operations for the stripe units indicated no data by the table, a time consumed for rebuilding can be significantly reduced, recovering the RAID array healthy sooner and reducing the impact on system bandwidth usage and host I/O performance impact during the rebuild process.