Abstract: Provided is a substrate supporting apparatus including: a mounting part provided with a first body brought into contact with a substrate so that the substrate is mounted thereon and a second body configured to surround the first body; and a support part connected under the mounting part so as to support the mounting part, wherein the first body and the second body include a plurality of protrusions, and an area of upper surfaces of the protrusions provided on the first body is formed larger than an area of upper surfaces of the protrusions provided on the second body, and thus, the substrate can be stably supported.

Abstract: A method for performing a preliminary search for cylinders in a hard disk drive. The method includes the steps of setting a target cylinder upon receiving a sequential data write command from the external device; setting search cylinders and setting a counter value to have a same value as a number of the search cylinders; sequentially searching the search cylinders for the target cylinder until the counter value becomes zero; and writing data on the target cylinder if the counter value is zero. Here, the search cylinders are positioned between the target cylinder and a current cylinder. The current cylinder is the cylinder where a disk head is located currently.