STARFISH is a parallel file-system simulator we built for our research into the concept of disk-directed I/O. In this report, we detail steps taken to tune the file systems supported by STARFISH, which include a traditional parallel file system (with caching) and a disk-directed I/O system. In particular, we now support two-phase I/O, use smarter disk scheduling, increased the maximum number of outstanding requests that a compute processor may make to each disk, and added gather/scatter block transfer. We also present results of the experiments driving the tuning effort.