A method for configuring a RAID (Redundant Array of Inexpensive Disks) includes the following steps. When a RAID instruction to access the RAID array is received, it is determined whether a removed hard drive unconnected to the RAID array is present in a hard drive list of the RAID array; when the removed hard drive unconnected to the RAID array is present in the hard drive list, the hard drive list of the RAID array is amended; it is detected whether a new hard drive connected to the RAID array is absent in the hard drive list; when the new hard drive connected to the RAID array is absent in the hard drive list, the hard drive list is amended; and the RAID instruction is executed to access the RAID array according to the hard drive list.