REDUNDANT RECORDING DISK DEVICE AND DATA PROCESSING METHOD USING PLURAL LOGICAL DISKS WITH MIRRORED DATA STORED WITH A PREDETERMINED PHASE-OFFSET

摘要

A recording medium 20 constitutes a mirror disk by taking a disk 21a as a first logical sub-disk and taking a disk 21b as a second logical sub-disk. Mirrored redundant data are recorded such that a recording position on the first logical sub-disk and a recording position on the second logical sub-disk are positions on the same cylinder and having a phase difference of 180 degrees around respective rotation axes of the disks with respect to one data. In a single disk device, therefore, the practical use of the disk device can be continued even when one recording surface is not usable by a fault, and the access speed of the disk can be increased when there is no fault.