METHOD AND APPARATUS FOR REDUCING REPEATABLE RUNOUT IN STORAGE SYSTEMS

摘要

A storage system includes a first buffer configured to store a first repeatable runout profile (RRP) for a sector of a rotating storage medium. A second buffer is configured to store a second RRP for the sector. A controller: controls a servo of the rotating storage medium based on the first RRP during a first revolution of the rotating storage medium; and learns the second RRP (i) while operating in a track-following mode, and (ii) during the first revolution. The controller ceases learning of the second RRP when one of (i) the controller is operating in a seek mode and (ii) the rotating storage medium is in an off-track state. Subsequent to the first revolution of the rotating storage medium and based on whether the learning of the second RRP was stopped during the first revolution, the controller replaces the first RRP with the second RRP in the first buffer.