SPEICHER FÜR PLATTENEINHEIT

摘要

The disk drive memory of the present invention uses a large plurality of small form factor disk drives to implement an inexpensive, high performance, high reliability disk drive memory that emulates the format and capability of large form factor disk drives. The plurality of disk drives are switchably interconnectable to form redundancy groups of N+M parallel connnected disk drives to store data thereon. The N+M disk drives are used to store the N segments of each data word plus M redundancy segments. In addition, a pool of R backup disk drives is maintained to automatically substitute a replacement disk drive for a disk drive in a redundancy group that fails during operation. The number N of data segments in each data redundancy group can be varied throughout the disk drive memory to thereby match the characteristics of the input data or operational parameters within the disk drive memory. Furthermore, a group of U unassigned disk drives can be maintained as a stock of disk drives that can be powered up as needed and assigned to either a redundancy group or to the pool of backup disk drives.