A method for writing a plurality of files that reduces average seek time includes receiving data of the plutality of files requested to be written to a tape from an application of a host, dividing a group of the received plurality of files into segments with specified sizes, and writing a series of the plurality of respective segments of the group of the plurality of files in sequence in a specified order, the respective segments having the specified sizes, wherein when writing the segments in the specified order, a left end portion of the tape is postioned and respective top segments of the files are first collectively written thereto. A tape drive system in which the method for writing is implemented reduces an average time required for seek of a plurality of image files.