System Dynamics and Disk Drive Head Position Error Prediction in a Data Storage Box

Disk drives are packed at ever dense arrangement in a modern data storage system, internal and external mechanical disturbances can have a great effect to disk drive’s read and write performances. The VCM torque generated during seeking affects its own as well as neighboring drives head position. In this study, we modeled a storage box with multiple HDDs installed to obtain mechanical system transfer function. The mechanical excitation is characterized by VCM torque, and HDD operational vibration behaviors on linear and rotational shakers are measured. A system level hybrid method predicting HDD head position error in a data storage box is described, and both analytical and measured results will be presented.