Method and apparatus for synchronizing the rotations of data storage disks in a plurality of disk storage devices

摘要

A synchronization technique is described which finds use in a disk array subsystem comprising a plurality of disk storage devices connected to a controller. In response to signals from each of the devices specifying their angular position at a particular time, the controller calculates the relative angular positions of the devices and issues a signal to each of the devices specifying the amount and direction of change in rotational velocity required to achieve synchronization. In a two device subsystem, the signal to one device will specify a speed decrease and the signal to the second device will specify a speed increase.